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Sample records for higher a-olefins carbonylation

  1. Protein carbonylation in plants

    DEFF Research Database (Denmark)

    Møller, Ian Max; Havelund, Jesper; Rogowska-Wrzesinska, Adelina

    2017-01-01

    This chapter provides an overview of the current knowledge on protein carbonylation in plants and its role in plant physiology. It starts with a brief outline of the turnover and production sites of reactive oxygen species (ROS) in plants and the causes of protein carbonylation. This is followed...... by a description of the methods used to study protein carbonylation in plants, which is also very brief as the methods are similar to those used in studies on animals. The chapter also focuses on protein carbonylation in plants in general and in mitochondria and in seeds in particular, as case stories where...

  2. Reciprocal carbonyl-carbonyl interactions in small molecules and proteins.

    Science.gov (United States)

    Rahim, Abdur; Saha, Pinaki; Jha, Kunal Kumar; Sukumar, Nagamani; Sarma, Bani Kanta

    2017-07-19

    Carbonyl-carbonyl n→π* interactions where a lone pair (n) of the oxygen atom of a carbonyl group is delocalized over the π* orbital of a nearby carbonyl group have attracted a lot of attention in recent years due to their ability to affect the 3D structure of small molecules, polyesters, peptides, and proteins. In this paper, we report the discovery of a "reciprocal" carbonyl-carbonyl interaction with substantial back and forth n→π* and π→π* electron delocalization between neighboring carbonyl groups. We have carried out experimental studies, analyses of crystallographic databases and theoretical calculations to show the presence of this interaction in both small molecules and proteins. In proteins, these interactions are primarily found in polyproline II (PPII) helices. As PPII are the most abundant secondary structures in unfolded proteins, we propose that these local interactions may have implications in protein folding.Carbonyl-carbonyl π* non covalent interactions affect the structure and stability of small molecules and proteins. Here, the authors carry out experimental studies, analyses of crystallographic databases and theoretical calculations to describe an additional type of carbonyl-carbonyl interaction.

  3. Validation of protein carbonyl measurement

    DEFF Research Database (Denmark)

    Augustyniak, Edyta; Adam, Aisha; Wojdyla, Katarzyna

    2015-01-01

    Protein carbonyls are widely analysed as a measure of protein oxidation. Several different methods exist for their determination. A previous study had described orders of magnitude variance that existed when protein carbonyls were analysed in a single laboratory by ELISA using different commercial...... kits. We have further explored the potential causes of variance in carbonyl analysis in a ring study. A soluble protein fraction was prepared from rat liver and exposed to 0, 5 and 15min of UV irradiation. Lyophilised preparations were distributed to six different laboratories that routinely undertook...... and control liver proteins, only seven were common in all three liver preparations. Lysine and arginine residues modified by carbonyls are likely to be resistant to tryptic proteolysis. Use of a cocktail of proteases may increase the recovery of oxidised peptides. In conclusion, standardisation is critical...

  4. Determination of Carbonyl Functional Groups in Bio-oils by Potentiometric Titration: The Faix Method.

    Science.gov (United States)

    Black, Stuart; Ferrell, Jack R

    2017-02-07

    Carbonyl compounds present in bio-oils are known to be responsible for bio-oil property changes upon storage and during upgrading. Specifically, carbonyls cause an increase in viscosity (often referred to as 'aging') during storage of bio-oils. As such, carbonyl content has previously been used as a method of tracking bio-oil aging and condensation reactions with less variability than viscosity measurements. Additionally, carbonyls are also responsible for coke formation in bio-oil upgrading processes. Given the importance of carbonyls in bio-oils, accurate analytical methods for their quantification are very important for the bio-oil community. Potentiometric titration methods based on carbonyl oximation have long been used for the determination of carbonyl content in pyrolysis bio-oils. Here, we present a modification of the traditional carbonyl oximation procedures that results in less reaction time, smaller sample size, higher precision, and more accurate carbonyl determinations. While traditional carbonyl oximation methods occur at room temperature, the Faix method presented here occurs at an elevated temperature of 80 °C.

  5. Carbonyl compounds in gas and particle phases of mainstream cigarette smoke

    Energy Technology Data Exchange (ETDEWEB)

    Pang, Xiaobing, E-mail: pangxbyuanj@gmail.com [Department of Chemistry, University of York, Heslington, York, YO10 5DD (United Kingdom); Lewis, Alastair C., E-mail: ally.lewis@york.ac.uk [National Centre for Atmospheric Science, University of York, Heslington, York, YO10 5DD (United Kingdom)

    2011-11-01

    Carbonyl compounds (carbonyls) are important constituents of cigarette smoke and some are toxic and may be carcinogenic or mutagenic to humans. In this study carbonyl emissions in the gas and particle phases of mainstream cigarette smoke were assessed by GC-MS with pentafluorophenyl hydrazine (PFPH) derivatization. Seven brands of cigarettes and one brand of cigar common in the UK market and having differing nicotine, tar and carbon monoxide yields were investigated. Sixteen carbonyl components were identified in gaseous emissions and twenty in the particle phase. In the gaseous emissions, acetaldehyde presented as the predominant species, followed by formaldehyde, 2-propenal, and pentanal. In the particulate emissions, 1-hydroxy-2-propanone was the most abundant followed by formaldehyde, benzaldehyde, and 2,5-dimethylbenzaldehyde. Significant differences were found in carbonyl emissions among the brands of cigarettes. The gaseous carbonyl emissions varied in the range of 216-405 {mu}g cigarette{sup -1} ({mu}g cig{sup -1}) and the particulate carbonyl emissions varied in the range of 23-127 {mu}g cig{sup -1}. Positive correlations were found between the total emission of carbonyls, tar yield and carbon monoxide yield. Similar gas/particle (G/P) partitioning ratios of carbonyls were found among all cigarettes, which implies that G/P partitions of carbonyls in smoke mainly depend on the physical properties of the carbonyls. The gaseous carbonyl emissions were enhanced by 40% to 130% when some of the water, accounting for 8-12% of cigarettes in mass, was removed from the tobacco. Non-filtered cigarettes showed significantly higher carbonyl emissions compared to their filtered equivalents. Carbonyl particulate accounted for 11-19% by mass of total particulate matter from tobacco smoke. The cigar generated 806 {mu}g cig{sup -1} gaseous and 141 {mu}g cig{sup -1} particulate carbonyls, which is 2-4 times greater than the cigarettes. - Highlights: {yields} Carbonyl

  6. Radical carbonylations using a continuous microflow system

    OpenAIRE

    Takahide Fukuyama; Md. Taifur Rahman; Naoya Kamata; Ilhyong Ryu

    2009-01-01

    Summary Radical-based carbonylation reactions of alkyl halides were conducted in a microflow reactor under pressurized carbon monoxide gas. Good to excellent yields of carbonylated products were obtained via radical formylation, carbonylative cyclization and three-component coupling reactions, using tributyltin hydride or TTMSS as a radical mediator.

  7. Radical carbonylations using a continuous microflow system

    Directory of Open Access Journals (Sweden)

    Takahide Fukuyama

    2009-07-01

    Full Text Available Radical-based carbonylation reactions of alkyl halides were conducted in a microflow reactor under pressurized carbon monoxide gas. Good to excellent yields of carbonylated products were obtained via radical formylation, carbonylative cyclization and three-component coupling reactions, using tributyltin hydride or TTMSS as a radical mediator.

  8. Transition metal catalyzed carbonylation reactions carbonylative activation of C-X bonds

    CERN Document Server

    Beller, Matthias

    2014-01-01

    This book provides students and researchers in organic synthesis with a detailed discussion of carbonylation from the basics through to applications. It discusses the past, present and future of carbonylation reactions.

  9. Transition-metal-catalyzed carbonylation reactions of olefins and alkynes: a personal account.

    Science.gov (United States)

    Wu, Xiao-Feng; Fang, Xianjie; Wu, Lipeng; Jackstell, Ralf; Neumann, Helfried; Beller, Matthias

    2014-04-15

    Carbon monoxide was discovered and identified in the 18th century. Since the first applications in industry 80 years ago, academic and industrial laboratories have broadly explored CO's use in chemical reactions. Today organic chemists routinely employ CO in organic chemistry to synthesize all kinds of carbonyl compounds. Despite all these achievements and a century of carbonylation catalysis, many important research questions and challenges remain. Notably, apart from academic developments, industry applies carbonylation reactions with CO on bulk scale. In fact, today the largest applications of homogeneous catalysis (regarding scale) are carbonylation reactions, especially hydroformylations. In addition, the vast majority of acetic acid is produced via carbonylation of methanol (Monsanto or Cativa process). The carbonylation of olefins/alkynes with nucleophiles, such as alcohols and amines, represent another important type of such reactions. In this Account, we discuss our work on various carbonylations of unsaturated compounds and related reactions. Rhodium-catalyzed isomerization and hydroformylation reactions of internal olefins provide straightforward access to higher value aldehydes. Catalytic hydroaminomethylations offer an ideal way to synthesize substituted amines and even heterocycles directly. More recently, our group has also developed so-called alternative metal catalysts based on iridium, ruthenium, and iron. What about the future of carbonylation reactions? CO is already one of the most versatile C1 building blocks for organic synthesis and is widely used in industry. However, because of CO's high toxicity and gaseous nature, organic chemists are often reluctant to apply carbonylations more frequently. In addition, new regulations have recently made the transportation of carbon monoxide more difficult. Hence, researchers will need to develop and more frequently use practical and benign CO-generating reagents. Apart from formates, alcohols, and metal

  10. Emissions of Toxic Carbonyls in an Electronic Cigarette

    Directory of Open Access Journals (Sweden)

    Guthery William

    2016-01-01

    Full Text Available Electronic cigarettes (e-cigs provide a smoke-free alternative for inhalation of nicotine without the vast array of toxic and carcinogenic combustion products produced by tobacco smoke. Elevated levels of toxic carbonyls may be generated during vaporisation; however, it is unclear whether that is indicative of a fault with the device or is due to the applied conditions of the test. A device, designed and built at this facility, was tested to determine the levels of selected toxic carbonyls. The reservoir was filled with approximately 960 mg of an e-liquid formulation containing 1.8% (w/v nicotine. Devices were puffed 200 times in blocks of 40 using a standardised regime consisting of a 55 mL puff volume; 3 s puff duration; 30 s puff interval; square wave puff profile. Confirmatory testing for nicotine and total aerosol delivery resulted in mean (n = 8 values of 10 mg (RSD 12.3% and 716 mg (RSD 11.2%, respectively. Emissions of toxic carbonyls were highly variable yet were between < 0.1% and 22.9% of expected levels from a Kentucky Reference Cigarette (K3R4F puffed 200 times under Health Canada Intense smoking conditions. It has been shown that a device built to a high specification with relatively consistent nicotine and aerosol delivery emits inconsistent levels of carbonyls. The exposure is greatly reduced when compared with lit tobacco products. However, it was observed that as the reservoirs neared depletion then emission levels were significantly higher

  11. Measurements of carbonyls in a 13-story building.

    Science.gov (United States)

    Báez, Armando P; Padilla, Hugo G; García, Rocío M; Belmont, Raúl D; Torres, Maria del Carmen B

    2004-01-01

    45% was observed in the fifth floor air after the air conditioning systems had been repaired. Formaldehyde and acetaldehyde concentrations were higher in smoking environments. Indoor carbonyl concentrations were significantly greater than outdoor concentrations. Tobacco smoke seems to be the main indoor source of formaldehyde. After the air conditioning system was maintained and repaired (as was recommended), an important reduction in the emission of formaldehyde and acetaldehyde was achieved on all floors, except for the 3rd level parking garage, thereby reducing the inhalation exposure doses. The results obtained in this research demonstrated that maintenance of air conditioning systems must be carried out regularly in order to avoid possible adverse effects on health. Additionally, it is mandatory that isolated smoking areas, with air extraction systems, be installed in every public building.

  12. Interresidue carbonyl-carbonyl polarization transfer experiments in uniformly 13C, 15N-labeled peptides and proteins

    Science.gov (United States)

    Janik, Rafal; Ritz, Emily; Gravelle, Andrew; Shi, Lichi; Peng, Xiaohu; Ladizhansky, Vladimir

    2010-03-01

    In this work, we demonstrate that Homonuclear Rotary Resonance Recoupling (HORROR) can be used to reintroduce carbonyl-carbonyl interresidue dipolar interactions and to achieve efficient polarization transfer between carbonyl atoms in uniformly 13C, 15N-labeled peptides and proteins. We show that the HORROR condition is anisotropically broadened and overall shifted to higher radio frequency intensities because of the CSA effects. These effects are analyzed theoretically using Average Hamiltonian Theory. At spinning frequencies used in this study, 22 kHz, this broadening is experimentally found to be on the order of a kilohertz at a proton field of 600 MHz. To match HORROR condition over all powder orientations, variable amplitude radio frequency (RF) fields are required, and efficient direct transfers on the order of 20-30% can be straightforwardly established. Two- and three-dimensional chemical shift correlation experiments establishing long-range interresidue connectivities (e.g., (N[i]-CO[i - 2])) are demonstrated on the model peptide N-acetyl-valine-leucine, and on the third immunoglobulin binding domain of protein G. Possible future developments are discussed.

  13. Characteristics of carbonyl compounds in public vehicles of Beijing city: Concentrations, sources, and personal exposures

    Science.gov (United States)

    Pang, Xiaobing; Mu, Yujing

    The characteristics of carbonyl compounds (carbonyls) including concentrations, major sources, and personal exposure were investigated for 29 vehicles including taxi, bus and subway in Beijing. It was found that the taxis (Xiali, TA) and buses (Huanghe, BA) fueled by gasoline with longer service years had the higher indoor carbonyl levels (178±42.7 and 188±31.6 μg m -3) while subways energized by electricity without exhaust and the jingwa buses (BB) driven in the suburb had the lower levels with total concentrations of 98.5±26.3 and 92.1±20.3 μg m -3, respectively. Outdoor carbonyls of taxi cars and buses were nearly at the same level with their total concentrations varying from 80 to 110 μg m -3. The level of outdoor subways carbonyls was equal with the ambient air levels. Exhaust leakage, indoor material emissions, photochemical formation, and infiltration of outdoor air were considered to be the major sources to in-vehicle carbonyls. Personal exposures and cancer risk to formaldehyde and acetaldehyde were calculated for professional bus and taxi drivers, respectively. Taxi drivers had the highest cancer risk with personal exposure to formaldehyde and acetaldehyde of 212 and 243 μg day -1, respectively. The public concern should pay considerable attention to professional drivers' health.

  14. Convenient Reduction of Carbonyl Compounds to their ...

    African Journals Online (AJOL)

    NICO

    Convenient Reduction of Carbonyl Compounds to their. Corresponding Alcohols with NaBH. 4. /(NH. 4. ) 2. C. 2. O. 4. System. Davood Setamdideh* and Sahar Ghahremani. Department of Chemistry, Faculty of Sciences, Mahabad Branch, Islamic Azad University, 59135-443, Iran. Received 6 January 2012, revised 14 ...

  15. Cyclometallated ruthenium (II) carbonyl complexes with 1 ...

    Indian Academy of Sciences (India)

    A facile method for the synthesis of a series of cyclometallated ruthenium(II) carbonyl complexes with 1-pyrenaldehyde 4-R-3-thiosemicarbazones (H2Ln where the two H's represent the dissociable thioamide and pyrenyl protons; R = H, Me and Ph) has been described. The characterization of the complexes having the ...

  16. Protein carbonylation, protein aggregation and neuronal cell death in a murine model of multiple sclerosis

    Science.gov (United States)

    Dasgupta, Anushka

    Many studies have suggested that oxidative stress plays an important role in the pathophysiology of both multiple sclerosis (MS) and its animal model experimental autoimmune encephalomyelitis (EAE). Yet, the mechanism by which oxidative stress leads to tissue damage in these disorders is unclear. Recent work from our laboratory has revealed that protein carbonylation, a major oxidative modification caused by severe and/or chronic oxidative stress conditions, is elevated in MS and EAE. Furthermore, protein carbonylation has been shown to alter protein structure leading to misfolding/aggregation. These findings prompted me to hypothesize that carbonylated proteins, formed as a consequence of oxidative stress and/or decreased proteasomal activity, promote protein aggregation to mediate neuronal apoptosis in vitro and in EAE. To test this novel hypothesis, I first characterized protein carbonylation, protein aggregation and apoptosis along the spinal cord during the course of myelin-oligodendrocyte glycoprotein (MOG)35-55 peptide-induced EAE in C57BL/6 mice [Chapter 2]. The results show that carbonylated proteins accumulate throughout the course of the disease, albeit by different mechanisms: increased oxidative stress in acute EAE and decreased proteasomal activity in chronic EAE. I discovered not only that there is a temporal correlation between protein carbonylation and apoptosis but also that carbonyl levels are significantly higher in apoptotic cells. A high number of juxta-nuclear and cytoplasmic protein aggregates containing the majority of the oxidized proteins are also present during the course of EAE, which seems to be due to reduced autophagy. In chapter 3, I show that when gluthathione levels are reduced to those in EAE spinal cord, both neuron-like PC12 (nPC12) cells and primary neuronal cultures accumulate carbonylated proteins and undergo cell death (both by necrosis and apoptosis). Immunocytochemical and biochemical studies also revealed a temporal

  17. Millimeter wave spectra of carbonyl cyanide ⋆

    Science.gov (United States)

    Bteich, S.B.; Tercero, B.; Cernicharo, J.; Motiyenko, R.A.; Margulès, L.; Guillemin, J.-C.

    2016-01-01

    Context More than 30 cyanide derivatives of simple organic molecules have been detected in the interstellar medium, but only one dicarbonitrile has been found and that very recently. There is still a lack of high-resolution spectroscopic data particularly for dinitriles derivatives. The carbonyl cyanide molecule is a new and interesting candidate for astrophysical detection. It could be formed by the reaction of CO and CN radicals, or by substitution of the hydrogen atom by a cyano group in cyanoformaldehyde, HC(=O)CN, that has already been detected in the interstellar medium. Aims The available data on the rotational spectrum of carbonyl cyanide is limited in terms of quantum number values and frequency range, and does not allow accurate extrapolation of the spectrum into the millimeter-wave range. To provide a firm basis for astrophysical detection of carbonyl cyanide we studied its millimeter-wave spectrum. Methods The rotational spectrum of carbonyl cyanide was measured in the frequency range 152 - 308 GHz and analyzed using Watson’s A- and S-reduction Hamiltonians. Results The ground and first excited state of v5 vibrational mode were assigned and analyzed. More than 1100 distinct frequency lines of the ground state were fitted to produce an accurate set of rotational and centrifugal distortion constants up to the eighth order. The frequency predictions based on these constants should be accurate enough for astrophysical searches in the frequency range up to 500 GHz and for transition involving energy levels with J ≤ 100 and Ka ≤ 42. Based on the results we searched for interstellar carbonyl cyanide in available observational data without success. Thus, we derived upper limits to its column density in different sources. PMID:27738349

  18. Effect of cooking and drying on carbonyls of oil sardine

    OpenAIRE

    Ammu, K.; Devadasan, K.

    1989-01-01

    Changes in the total as well as major individual carbonyls of oil sardine during steam cooking, oven drying, sun drying and freeze drying are presented. Carbonyls extracted with hexane were converted to their 2:4 dinitro phenyl hydrazone (DNPH) derivatives and were separated into major classes by column chromatography on celite/magnesia. Individual carbonyls were then identified by capillary gas chromatography of the DNPH derivatives. Dehydration and heating increase the carbonyl production f...

  19. Transition-Metal-Catalyzed Carbonylation of Methyl Acetate.

    Science.gov (United States)

    Polichnowski, S. W.

    1986-01-01

    Presents a study of the rhodium-catalyzed, ioding-promoted carbonylation of methyl acetate. This study provides an interesting contrast between the carbonylation of methyl acetate and the carbonylation of methanol when similar rhodium/iodine catalyst systems are used. (JN)

  20. Carbonyl compounds and dissolved organic carbon in rainwater of an urban atmosphere.

    Science.gov (United States)

    Balla, D; Papageorgiou, A; Voutsa, D

    2014-10-01

    This study investigates the occurrence of carbonyl compounds in rainwater at the city of Thessaloniki, Northern Greece. The concentrations of carbonyl compounds (as sum of 14 compounds) ranged from 21.8 to 592 μg/L, mean concentration 119 μg/L. Formaldehyde, acetaldehyde, hexanal, glyoxal, and methylglyoxal were the dominant compounds. DOC concentrations in rainwater ranged from 0.46 to 21.3 mg/L. UV-Vis and fluorescence spectra characteristics showed variation among rain events. Carbonyl compounds were negatively correlated with temperature exhibited relatively higher concentrations in cold season. They also influenced by storm origin with higher concentrations under terrestrial air masses. Calm conditions enhance the concentrations of DOC. Wash out is an effective removal mechanism of DOC.

  1. Molecular Engineering with Organic Carbonyl Electrode Materials for Advanced Stationary and Redox Flow Rechargeable Batteries.

    Science.gov (United States)

    Zhao, Qing; Zhu, Zhiqiang; Chen, Jun

    2017-12-01

    Organic carbonyl electrode materials that have the advantages of high capacity, low cost and being environmentally friendly, are regarded as powerful candidates for next-generation stationary and redox flow rechargeable batteries (RFBs). However, low carbonyl utilization, poor electronic conductivity and undesired dissolution in electrolyte are urgent issues to be solved. Here, we summarize a molecular engineering approach for tuning the capacity, working potential, concentration of active species, kinetics, and stability of stationary and redox flow batteries, which well resolves the problems of organic carbonyl electrode materials. As an example, in stationary batteries, 9,10-anthraquinone (AQ) with two carbonyls delivers a capacity of 257 mAh g -1 (2.27 V vs Li + /Li), while increasing the number of carbonyls to four with the formation of 5,7,12,14-pentacenetetrone results in a higher capacity of 317 mAh g -1 (2.60 V vs Li + /Li). In RFBs, AQ, which is less soluble in aqueous electrolyte, reaches 1 M by grafting -SO 3 H with the formation of 9,10-anthraquinone-2,7-disulphonic acid, resulting in a power density exceeding 0.6 W cm -2 with long cycling life. Therefore, through regulating substituent groups, conjugated structures, Coulomb interactions, and the molecular weight, the electrochemical performance of carbonyl electrode materials can be rationally optimized. This review offers fundamental principles and insight into designing advanced carbonyl materials for the electrodes of next-generation rechargeable batteries. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Carbonyl Compounds Produced by Vaporizing Cannabis Oil Thinning Agents.

    Science.gov (United States)

    Troutt, William D; DiDonato, Matthew D

    2017-11-01

    Cannabis use has increased in the United States, particularly the use of vaporized cannabis oil, which is often mixed with thinning agents for use in vaporizing devices. E-cigarette research shows that heated thinning agents produce potentially harmful carbonyls; however, similar studies have not been conducted (1) with agents that are commonly used in the cannabis industry and (2) at temperatures that are appropriate for cannabis oil vaporization. The goal of this study was to determine whether thinning agents used in the cannabis industry produce potentially harmful carbonyls when heated to a temperature that is appropriate for cannabis oil vaporization. Four thinning agents (propylene glycol [PG], vegetable glycerin [VG], polyethylene glycol 400 [PEG 400], and medium chain triglycerides [MCT]) were heated to 230°C and the resulting vapors were tested for acetaldehyde, acrolein, and formaldehyde. Each agent was tested three times. Testing was conducted in a smoking laboratory. Carbonyl levels were measured in micrograms per puff block. Analyses showed that PEG 400 produced significantly higher levels of acetaldehyde and formaldehyde than PG, MCT, and VG. Formaldehyde production was also significantly greater in PG compared with MCT and VG. Acrolein production did not differ significantly across the agents. PG and PEG 400 produced high levels of acetaldehyde and formaldehyde when heated to 230°C. Formaldehyde production from PEG 400 isolate was particularly high, with one inhalation accounting for 1.12% of the daily exposure limit, nearly the same exposure as smoking one cigarette. Because PG and PEG 400 are often mixed with cannabis oil, individuals who vaporize cannabis oil products may risk exposure to harmful formaldehyde levels. Although more research is needed, consumers and policy makers should consider these potential health effects before use and when drafting cannabis-related legislation.

  3. Oxidation of Reduced Sulfur Species: Carbonyl Sulfide

    DEFF Research Database (Denmark)

    Glarborg, Peter; Marshall, Paul

    2013-01-01

    A detailed chemical kinetic model for oxidation of carbonyl sulfide (OCS) has been developed, based on a critical evaluation of data from the literature. The mechanism has been validated against experimental results from batch reactors, flow reactors, and shock tubes. The model predicts satisfact...... by the competition between chain‐branching and ‐propagating steps; modeling predictions are particularly sensitive to the branching fraction for the OCS + O reaction to form CO + SO or CO2 + S.......A detailed chemical kinetic model for oxidation of carbonyl sulfide (OCS) has been developed, based on a critical evaluation of data from the literature. The mechanism has been validated against experimental results from batch reactors, flow reactors, and shock tubes. The model predicts...

  4. Carbonyl Compounds Generated from Electronic Cigarettes

    Directory of Open Access Journals (Sweden)

    Kanae Bekki

    2014-10-01

    Full Text Available Electronic cigarettes (e-cigarettes are advertised as being safer than tobacco cigarettes products as the chemical compounds inhaled from e-cigarettes are believed to be fewer and less toxic than those from tobacco cigarettes. Therefore, continuous careful monitoring and risk management of e-cigarettes should be implemented, with the aim of protecting and promoting public health worldwide. Moreover, basic scientific data are required for the regulation of e-cigarette. To date, there have been reports of many hazardous chemical compounds generated from e-cigarettes, particularly carbonyl compounds such as formaldehyde, acetaldehyde, acrolein, and glyoxal, which are often found in e-cigarette aerosols. These carbonyl compounds are incidentally generated by the oxidation of e-liquid (liquid in e-cigarette; glycerol and glycols when the liquid comes in contact with the heated nichrome wire. The compositions and concentrations of these compounds vary depending on the type of e-liquid and the battery voltage. In some cases, extremely high concentrations of these carbonyl compounds are generated, and may contribute to various health effects. Suppliers, risk management organizations, and users of e-cigarettes should be aware of this phenomenon.

  5. Carbonyl compounds generated from electronic cigarettes.

    Science.gov (United States)

    Bekki, Kanae; Uchiyama, Shigehisa; Ohta, Kazushi; Inaba, Yohei; Nakagome, Hideki; Kunugita, Naoki

    2014-10-28

    Electronic cigarettes (e-cigarettes) are advertised as being safer than tobacco cigarettes products as the chemical compounds inhaled from e-cigarettes are believed to be fewer and less toxic than those from tobacco cigarettes. Therefore, continuous careful monitoring and risk management of e-cigarettes should be implemented, with the aim of protecting and promoting public health worldwide. Moreover, basic scientific data are required for the regulation of e-cigarette. To date, there have been reports of many hazardous chemical compounds generated from e-cigarettes, particularly carbonyl compounds such as formaldehyde, acetaldehyde, acrolein, and glyoxal, which are often found in e-cigarette aerosols. These carbonyl compounds are incidentally generated by the oxidation of e-liquid (liquid in e-cigarette; glycerol and glycols) when the liquid comes in contact with the heated nichrome wire. The compositions and concentrations of these compounds vary depending on the type of e-liquid and the battery voltage. In some cases, extremely high concentrations of these carbonyl compounds are generated, and may contribute to various health effects. Suppliers, risk management organizations, and users of e-cigarettes should be aware of this phenomenon.

  6. Inactivation of cellular enzymes by carbonyls and protein-bound glycation/glycoxidation products

    DEFF Research Database (Denmark)

    Morgan, Philip E; Dean, Roger T; Davies, Michael Jonathan

    2002-01-01

    dismutase, or catalase dependent, suggesting that inhibition is not radical mediated. These effects are suggested to be due to direct adduction of the free- or protein-bound carbonyls with the target enzyme. Such an interpretation is supported by the detection of the loss of thiol groups on GAPDH...... and the detection of cross-linked materials on protein gels. Though direct comparison of the extent of inhibition induced by free versus protein-bound carbonyls was not possible, the significantly higher concentrations of the latter materials over the former in diabetic plasma and cells lead us to suggest...

  7. Millimeter wave spectra of carbonyl cyanide

    Science.gov (United States)

    Bteich, S. B.; Tercero, B.; Cernicharo, J.; Motiyenko, R. A.; Margulès, L.; Guillemin, J.-C.

    2016-07-01

    Context. More than 30 cyanide derivatives of simple organic molecules have been detected in the interstellar medium, but only one dicarbonitrile has been found and that very recently. There is still a lack of high-resolution spectroscopic data particularly for dinitriles derivatives. The carbonyl cyanide molecule is a new and interesting candidate for astrophysical detection. It could be formed by the reaction of CO and CN radicals, or by substitution of the hydrogen atom by a cyano group in cyanoformaldehyde, HC(=O)CN, that has already been detected in the interstellar medium. Aims: The available data on the rotational spectrum of carbonyl cyanide is limited in terms of quantum number values and frequency range, and does not allow accurate extrapolation of the spectrum into the millimeter-wave range. To provide a firm basis for astrophysical detection of carbonyl cyanide we studied its millimeter-wave spectrum. Methods: The rotational spectrum of carbonyl cyanide was measured in the frequency range 152-308 GHz and analyzed using Watson's A- and S-reduction Hamiltonians. Results: The ground and first excited state of v5 vibrational mode were assigned and analyzed. More than 1100 distinct frequency lines of the ground state were fitted to produce an accurate set of rotational and centrifugal distortion constants up to the eighth order. The frequency predictions based on these constants should be accurate enough for astrophysical searches in the frequency range up to 500 GHz and for transition involving energy levels with J ≤ 100 and Ka ≤ 42. Based on the results we searched for interstellar carbonyl cyanide in available observational data without success. Thus, we derived upper limits to its column density in different sources. This paper makes use of the following ALMA data: ADS/JAO.ALMA#2011.0.00009.SV. ALMA is a partnership of ESO (representing its member states), NSF (USA), and NINS (Japan) with NRC (Canada), NSC, and ASIAA (Taiwan), and KASI (Republic of

  8. Carbonyl Emissions from Gasoline and Diesel Motor Vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Destaillats, Hugo; Jakober, Chris A.; Robert, Michael A.; Riddle, Sarah G.; Destaillats, Hugo; Charles, M. Judith; Green, Peter G.; Kleeman, Michael J.

    2007-12-01

    Carbonyls from gasoline powered light-duty vehicles (LDVs) and heavy-duty diesel powered vehicles (HDDVs) operated on chassis dynamometers were measured using an annular denuder-quartz filter-polyurethane foam sampler with O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine derivatization and chromatography-mass spectrometry analyses. Two internal standards were utilized based on carbonyl recovery, 4-fluorobenzaldehyde forcarbonyls and 6-fluoro-4-chromanone for>_C8 compounds. Gas- and particle-phase emissions for 39 aliphatic and 20 aromatic carbonyls ranged from 0.1 ? 2000 ?g/L fuel for LDVs and 1.8 - 27000 mu g/L fuel for HDDVs. Gas-phase species accounted for 81-95percent of the total carbonyls from LDVs and 86-88percent from HDDVs. Particulate carbonyls emitted from a HDDV under realistic driving conditions were similar to concentrations measured in a diesel particulate matter (PM) standard reference material. Carbonyls accounted for 19percent of particulate organic carbon (POC) emissions from low-emission LDVs and 37percent of POC emissions from three-way catalyst equipped LDVs. This identifies carbonyls as one of the largest classes of compounds in LDV PM emissions. The carbonyl fraction of HDDV POC was lower, 3.3-3.9percent depending upon operational conditions. Partitioning analysis indicates the carbonyls had not achieved equilibrium between the gas- and particle-phase under the dilution factors of 126-584 used in the current study.

  9. Carbonyl emissions from heavy-duty diesel vehicle exhaust in China and the contribution to ozone formation potential.

    Science.gov (United States)

    Dong, Dong; Shao, Min; Li, Yue; Lu, Sihua; Wang, Yanjun; Ji, Zhe; Tang, Dagang

    2014-01-01

    Fifteen heavy-duty diesel vehicles were tested on chassis dynamometer by using typical heavy duty driving cycle and fuel economy cycle. The air from the exhaust was sampled by 2,4-dinitrophenyhydrazine cartridge and 23 carbonyl compounds were analyzed by high performance liquid chromatography. The average emission factor of carbonyls was 97.2 mg/km, higher than that of light-duty diesel vehicles and gasoline-powered vehicles. Formaldehyde, acetaldehyde, acetone and propionaldehyde were the species with the highest emission factors. Main influencing factors for carbonyl emissions were vehicle type, average speed and regulated emission standard, and the impact of vehicle loading was not evident in this study. National emission of carbonyls from diesel vehicles exhaust was calculated for China, 2011, based on both vehicle miles traveled and fuel consumption. Carbonyl emission of diesel vehicle was estimated to be 45.8 Gg, and was comparable to gasoline-powered vehicles (58.4 Gg). The emissions of formaldehyde, acetaldehyde and acetone were 12.6, 6.9, 3.8 Gg, respectively. The ozone formation potential of carbonyls from diesel vehicles exhaust was 537 mg O3/km, higher than 497 mg O3/km of none-methane hydrocarbons emitted from diesel vehicles.

  10. Spatial distributions of and diurnal variations in low molecular weight carbonyl compounds in coastal seawater, and the controlling factors

    Energy Technology Data Exchange (ETDEWEB)

    Takeda, Kazuhiko, E-mail: takedaq@hiroshima-u.ac.jp [Graduate School of Biosphere Science, Hiroshima University, 1-7-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8521 (Japan); Katoh, Shinya; Mitsui, Yumi; Nakano, Shinichi [Graduate School of Biosphere Science, Hiroshima University, 1-7-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8521 (Japan); Nakatani, Nobutake [Graduate School of Biosphere Science, Hiroshima University, 1-7-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8521 (Japan); Department of Environmental and Symbiotic Sciences, Rakuno Gakuen University, 582 Bunkyodai-Midorimachi, Ebetsu, Hokkaido 069-8501 (Japan); Sakugawa, Hiroshi [Graduate School of Biosphere Science, Hiroshima University, 1-7-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8521 (Japan)

    2014-09-15

    We studied the spatial distributions of and the diurnal variations in four low molecular weight (LMW) carbonyl compounds, formaldehyde, acetaldehyde, propionaldehyde, and glyoxal, in coastal seawater. The samples were taken from the coastal areas of Hiroshima Bay, the Iyo Nada, and the Bungo Channel, western Japan. The formaldehyde, acetaldehyde, and glyoxal concentrations were higher in the northern part of Hiroshima Bay than at offshore sampling points in the Iyo Nada and the Bungo Channel. These three compounds were found at much higher concentrations in the surface water than in deeper water layers in Hiroshima Bay. It is noteworthy that propionaldehyde was not detected in any of the seawater samples, the concentrations present being lower than the detection limit (1 nanomole per liter (nM)) of the high performance liquid chromatography (HPLC) system we used. Photochemical and biological experiments were performed in the laboratory to help understand the characteristic distributions and fates of the LMW carbonyl compounds. The primary process controlling their fate in the coastal environment appears to be their biological consumption. The direct photo degradation of propionaldehyde, initiated by ultraviolet (UV) absorption, was observed, although formaldehyde and acetaldehyde were not degraded by UV irradiation. Our results suggest that the degradation of the LMW carbonyl compounds by photochemically formed hydroxyl radicals is relatively insignificant in the study area. Atmospheric deposition is a possible source of soluble carbonyl compounds in coastal surface seawater, but it may not influence the carbonyl concentrations in offshore waters. - Highlights: • Low molecular weight (LMW) carbonyl compounds in coastal seawater were determined. • Photochemical productions of LMW carbonyl compounds in seawater were observed. • LMW carbonyl compounds were largely consumed biologically. • Photochemical degradation was relatively insignificant in the study area.

  11. Acute inhalation toxicity of carbonyl sulfide

    Energy Technology Data Exchange (ETDEWEB)

    Benson, J.M.; Hahn, F.F.; Barr, E.B. [and others

    1995-12-01

    Carbonyl sulfide (COS), a colorless gas, is a side product of industrial procedures sure as coal hydrogenation and gasification. It is structurally related to and is a metabolite of carbon disulfide. COS is metabolized in the body by carbonic anhydrase to hydrogen sulfide (H{sub 2}S), which is thought to be responsible for COS toxicity. No threshold limit value for COS has been established. Results of these studies indicate COS (with an LC{sub 50} of 590 ppm) is slightly less acutely toxic than H{sub 2}S (LC{sub 50} of 440 ppm).

  12. Impaired cardiac SIRT1 activity by carbonyl stress contributes to aging-related ischemic intolerance.

    Directory of Open Access Journals (Sweden)

    Chunhu Gu

    Full Text Available Reactive aldehydes can initiate protein oxidative damage which may contribute to heart senescence. Sirtuin 1 (SIRT1 is considered to be a potential interventional target for I/R injury management in the elderly. We hypothesized that aldehyde mediated carbonyl stress increases susceptibility of aged hearts to ischemia/reperfusion (I/R injury, and elucidate the underlying mechanisms with a focus on SIRT1. Male C57BL/6 young (4-6 mo and aged (22-24 mo mice were subjected to myocardial I/R. Cardiac aldehyde dehydrogenase (ALDH2, SIRT1 activity and protein carbonyls were assessed. Our data revealed that aged heart exhibited increased endogenous aldehyde/carbonyl stress due to impaired ALDH2 activity concomitant with blunted SIRT1 activity (P<0.05. Exogenous toxic aldehydes (4-HNE exposure in isolated cardiomyocyte verified that aldehyde-induced carbonyl modification on SIRT1 impaired SIRT1 activity leading to worse hypoxia/reoxygenation (H/R injury, which could all be rescued by Alda-1 (ALDH2 activator (all P<0.05. However, SIRT1 inhibitor blocked the protective effect of Alda-1 on H/R cardiomyocyte. Interestingly, myocardial I/R leads to higher carbonylation but lower activity of SIRT1 in aged hearts than that seen in young hearts (P<0.05. The application of Alda-1 significantly reduced the carbonylation on SIRT1 and markedly improved the tolerance to in vivo I/R injury in aged hearts, but failed to protect Sirt1(+/- knockout mice against myocardial I/R injury. This was verified by Alda-1 treatment improved postischemic contractile function recovery in ex vivo perfused aged but not in Sirt1(+/- hearts. Thus, aldehyde/carbonyl stress is accelerated in aging heart. These results provide a new insight that impaired cardiac SIRT1 activity by carbonyl stress plays a critical role in the increased susceptibility of aged heart to I/R injury. ALDH2 activation can restore this aging-related myocardial ischemic intolerance.

  13. Bifunctional dendrons for multiple carbohydrate presentation via carbonyl chemistry

    Directory of Open Access Journals (Sweden)

    Davide Bini

    2014-07-01

    Full Text Available The synthesis of new dendrons of the generations 0, 1 and 2 with a double bond at the focal point and a carbonyl group at the termini has been carried out. The carbonyl group has been exploited for the multivalent conjugation to a sample saccharide by reductive amination and alkoxyamine conjugation.

  14. Electromagnetic properties of carbonyl iron and their microwave ...

    Indian Academy of Sciences (India)

    Electromagnetic properties of carbonyl iron and their microwave absorbing characterization as filler in silicone rubber. Yuping Duan Guofang ... The complex permittivity, permeability and microwave-absorbing properties of rubber composites filled with carbonyl iron are measured at frequencies from 2–18 GHz. The results ...

  15. [High throughput screening of active and stereoselective carbonyl reductases].

    Science.gov (United States)

    Zhang, Hang; Chen, Xi; Feng, Jinhui; Bao, Jinku; Wu, Qiaqing; Zhu, Dunming

    2015-02-01

    In this study, a fast carbonyl reductases colorimetric screening method for discovering stereoselective carbonyl reductases was established by combining the reverse alcohol oxidation with the azoreductase-catalyzed reduction of azo dye. When azo dye (Orange I , 4-(4-hydroxy-1-naphthylazo) benzenesulfonic acid) and azoreductase (AzoB) were added into the reaction system of alcohol oxidation catalyzed by carbonyl reductase, the produced NAD(P)H served as electron donor for the azoreductase to reduce the azo dye, resulting the color fade. Hence, the carbonyl reductases can be screened by the obvious color change. When chiral alcohol was used as the substrate, the activity and stereoselectivity of carbonyl reductases can be screened at the same time.

  16. Aldehydes as alkyl carbanion equivalents for additions to carbonyl compounds

    Science.gov (United States)

    Wang, Haining; Dai, Xi-Jie; Li, Chao-Jun

    2017-04-01

    Nucleophilic addition reactions of organometallic reagents to carbonyl compounds for carbon-carbon bond construction have played a pivotal role in modern chemistry. However, this reaction's reliance on petroleum-derived chemical feedstocks and a stoichiometric quantity of metal have prompted the development of many carbanion equivalents and catalytic metal alternatives. Here, we show that naturally occurring carbonyls can be used as latent alkyl carbanion equivalents for additions to carbonyl compounds, via reductive polarity reversal. Such 'umpolung' reactivity is facilitated by a ruthenium catalyst and diphosphine ligand under mild conditions, delivering synthetically valuable secondary and tertiary alcohols in up to 98% yield. The unique chemoselectivity exhibited by carbonyl-derived carbanion equivalents is demonstrated by their tolerance to protic reaction media and good functional group compatibility. Enantioenriched tertiary alcohols can also be accessed with the aid of chiral ligands, albeit with moderate stereocontrol. Such carbonyl-derived carbanion equivalents are anticipated to find broad utility in chemical bond formation.

  17. The Hydrolysis of Carbonyl Sulfide at Low Temperature: A Review

    Science.gov (United States)

    Zhao, Shunzheng; Yi, Honghong; Tang, Xiaolong; Jiang, Shanxue; Gao, Fengyu; Zhang, Bowen; Zuo, Yanran; Wang, Zhixiang

    2013-01-01

    Catalytic hydrolysis technology of carbonyl sulfide (COS) at low temperature was reviewed, including the development of catalysts, reaction kinetics, and reaction mechanism of COS hydrolysis. It was indicated that the catalysts are mainly involved metal oxide and activated carbon. The active ingredients which can load on COS hydrolysis catalyst include alkali metal, alkaline earth metal, transition metal oxides, rare earth metal oxides, mixed metal oxides, and nanometal oxides. The catalytic hydrolysis of COS is a first-order reaction with respect to carbonyl sulfide, while the reaction order of water changes as the reaction conditions change. The controlling steps are also different because the reaction conditions such as concentration of carbonyl sulfide, reaction temperature, water-air ratio, and reaction atmosphere are different. The hydrolysis of carbonyl sulfide is base-catalyzed reaction, and the force of the base site has an important effect on the hydrolysis of carbonyl sulfide. PMID:23956697

  18. High throughput assay for evaluation of reactive carbonyl scavenging capacity

    Directory of Open Access Journals (Sweden)

    N. Vidal

    2014-01-01

    Full Text Available Many carbonyl species from either lipid peroxidation or glycoxidation are extremely reactive and can disrupt the function of proteins and enzymes. 4-hydroxynonenal and methylglyoxal are the most abundant and toxic lipid-derived reactive carbonyl species. The presence of these toxics leads to carbonyl stress and cause a significant amount of macromolecular damages in several diseases. Much evidence indicates trapping of reactive carbonyl intermediates may be a useful strategy for inhibiting or decreasing carbonyl stress-associated pathologies. There is no rapid and convenient analytical method available for the assessment of direct carbonyl scavenging capacity, and a very limited number of carbonyl scavengers have been identified to date, their therapeutic potential being highlighted only recently. In this context, we have developed a new and rapid sensitive fluorimetric method for the assessment of reactive carbonyl scavengers without involvement glycoxidation systems. Efficacy of various thiol- and non-thiol-carbonyl scavenger pharmacophores was tested both using this screening assay adapted to 96-well microplates and in cultured cells. The scavenging effects on the formation of Advanced Glycation End-product of Bovine Serum Albumin formed with methylglyoxal, 4-hydroxynonenal and glucose-glycated as molecular models were also examined. Low molecular mass thiols with an α-amino-β-mercaptoethane structure showed the highest degree of inhibitory activity toward both α,β-unsaturated aldehydes and dicarbonyls. Cysteine and cysteamine have the best scavenging ability toward methylglyoxal. WR-1065 which is currently approved for clinical use as a protective agent against radiation and renal toxicity was identified as the best inhibitor of 4-hydroxynonenal.

  19. 16th Carbonyl Metabolism Meeting: from enzymology to genomics

    Directory of Open Access Journals (Sweden)

    Maser Edmund

    2012-12-01

    Full Text Available Abstract The 16th International Meeting on the Enzymology and Molecular Biology of Carbonyl Metabolism, Castle of Ploen (Schleswig-Holstein, Germany, July 10–15, 2012, covered all aspects of NAD(P-dependent oxido-reductases that are involved in the general metabolism of xenobiotic and physiological carbonyl compounds. Starting 30 years ago with enzyme purification, structure elucidation and enzyme kinetics, the Carbonyl Society members have meanwhile established internationally recognized enzyme nomenclature systems and now consider aspects of enzyme genomics and enzyme evolution along with their roles in diseases. The 16th international meeting included lectures from international speakers from all over the world.

  20. Cobalt carbonyl-catalyzed carbonylation of functionalized aziridines to versatile β-lactam building blocks.

    Science.gov (United States)

    Piens, Nicola; Van Hecke, Kristof; Vogt, Dieter; D'hooghe, Matthias

    2017-06-07

    The Co2(CO)8-catalyzed carbonylation of different classes of non-activated aziridines with diverse substitution patterns was investigated. Special attention was devoted to selectivity issues and reaction optimization. This study resulted in the regio- and stereospecific synthesis of 24 novel β-lactam target structures in high yields on a multigram scale. The synthetic potential of the newly obtained azetidin-2-ones was illustrated via ring-expansion, ring-closure, and/or side chain-functionalization protocols to provide a straightforward entry to novel pyrrolidines, C-fused bi- and tricyclic β-lactams and monocyclic carbapenem analogs.

  1. Efficiency of Carbonyl Iron in Prevention of Anaemia in Piglets

    Directory of Open Access Journals (Sweden)

    M. Svoboda

    2007-01-01

    Full Text Available The aim of this study was to evaluate efficiency of elemental iron preparation in the form of carbonyl iron in prevention of iron deficiency in piglets. The piglets in group I (n = 14 were given 210 mg of carbonyl iron orally at the age of 3 days. The piglets in group II (n = 15 received 210 mg of carbonyl iron orally on days 3 and 9. In group III (n = 14 the piglets were injected i.m. with 200 mg Fe3+ as iron dextran. Fourteen days after birth, haemoglobin concentration in group I started to decrease and the piglets developed anaemia. In group II, at the age of 28 days, Hb dropped below 80 g/l and the piglets developed anaemia. Under conditions of this trial, the oral administration of carbonyl iron did not prevent development of iron deficiency in piglets.

  2. Keto-Enol Tautomers in a Carbonyl Phosphonium Salt

    Science.gov (United States)

    Berry, David E.; Patenaude, G. W.

    2002-04-01

    Supplementary NMR data is provided for an experiment previously published in this Journal describing the synthesis of carbonyl-stabilized ylides. The new data suggest that the keto-enol tautomerism is taking place in the phosphonium ion.

  3. Synthesis of main-chain metal carbonyl organometallic macromolecules (MCMCOMs).

    Science.gov (United States)

    Cao, Kai; Murshid, Nimer; Wang, Xiaosong

    2015-04-01

    Synthesis of main-chain metal carbonyl organometallic macromolecules (MCMCOMs) is difficult, mainly due to the instability of metal carbonyl complexes. Despite its challenge a number of MCMCOMs has been prepared by strategically using organometallic, organic, and polymer synthetic chemistry. Main contributions to this research field were reported by the groups of Tyler, Pannell, and Wang and are briefly summarized in this article. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Complex permeability and permittivity variation of carbonyl iron rubber in the frequency range of 2 to 18 GHz

    Directory of Open Access Journals (Sweden)

    Adriana Medeiros Gama

    2010-04-01

    Full Text Available The complex dielectric permittivity (e and magnetic permeability (m of Radar Absorbing Materials (RAM based on metallic magnetic particles (carbonyl iron particles embedded in a dielectric matrix (silicon rubber have been studied in the frequency range of 2 to 18 GHz. The relative permeability and permittivity of carbonyl iron-silicon composites for various mass fractions are measured by the transmission/reflection method using a vector network analyzer. The concentration dependence of permittivity and permeability on the frequency is analyzed. In a general way, the results show that e´ parameter shows a more significant variation among the evaluated parameters (e”, m”, m’. The comparison of dielectric and magnetic loss tangents (e”/e” and m”/m’, respectively shows more clearly the variation of both parameters (e and m according to the frequency. It is also observed that higher carbonyl iron content fractions favor both dielectric and magnetic loss tangents.

  5. Chemical probes for analysis of carbonylated proteins: a review.

    Science.gov (United States)

    Yan, Liang-Jun; Forster, Michael J

    2011-05-15

    Protein carbonylation is a major form of protein oxidation and is widely used as an indicator of oxidative stress. Carbonyl groups do not have distinguishing UV or visible, spectrophotometric absorbance/fluorescence characteristics and thus their detection and quantification can only be achieved using specific chemical probes. In this paper, we review the advantages and disadvantages of several chemical probes that have been and are still being used for protein carbonyl analysis. These probes include 2,4-dinitrophenylhydazine (DNPH), tritiated sodium borohydride ([(3)H]NaBH(4)), biotin-containing probes, and fluorescence probes. As our discussions lean toward gel-based approaches, utilizations of these probes in 2D gel-based proteomic analysis of carbonylated proteins are illustrated where applicable. Analysis of carbonylated proteins by ELISA, immunofluorescent imaging, near infrared fluorescence detection, and gel-free proteomic approaches are also discussed where appropriate. Additionally, potential applications of blue native gel electrophoresis as a tool for first dimensional separation in 2D gel-based analysis of carbonylated proteins are discussed as well. Copyright © 2010 Elsevier B.V. All rights reserved.

  6. Cytoskeletal protein carbonylation and degradation in experimental autoimmune encephalomyelitis

    Science.gov (United States)

    Smerjac, Suzanne M.; Bizzozero, Oscar A.

    2013-01-01

    Protein carbonylation, the non-enzymatic addition of aldehydes or ketones to specific amino acid residues, has been implicated in the pathophysiology of multiple sclerosis (MS). In this study we investigated whether protein carbonyls (PCOs) also accumulate in the spinal cord of Lewis rats with acute experimental autoimmune encephalomyelitis (EAE). Western blots analysis after derivatization with dinitrophenyl hydrazine (oxyblot) showed elevated protein carbonylation at the time of maximal clinical disability. During the same period glutathione levels were substantially reduced, suggesting a causal relationship between these two markers. In contrast, lipid peroxidation products accumulated in EAE spinal cord well before the appearance of neurological symptoms. Carbonyl staining was not restricted to inflammatory lesions but present throughout the spinal cord particularly in neuronal cell bodies and axons. By 2-dimensional-oxyblot we identified several cytoskeletal proteins, including β-actin, GFAP and the neurofilament proteins as the major targets of carbonylation. These findings were confirmed by pull-down experiments, which also showed an increase in the number of carbonylated β-actin molecules and a decrease in that of oxidized neurofilament proteins in EAE. These data suggest the possibility that oxidation targets neurofilament proteins for degradation, which may contribute to axonal pathology observed in MS and EAE. PMID:18088377

  7. Carbonyl species characteristics during the evaporation of essential oils

    Science.gov (United States)

    Chiang, Hsiu-Mei; Chiu, Hua-Hsien; Lai, Yen-Ming; Chen, Ching-Yen; Chiang, Hung-Lung

    2010-06-01

    Carbonyls emitted from essential oils can affect the air quality when they are used in indoors, especially under poor ventilation conditions. Lavender, lemon, rose, rosemary, and tea tree oils were selected as typical and popular essential oils to investigate in terms of composition, thermal characteristics and fifteen carbonyl constituents. Based on thermogravimetric (TG) analysis, the activation energy was 7.6-8.3 kcal mol -1, the reaction order was in the range of 0.6-0.7 and the frequency factor was 360-2838 min -1. Formaldehyde, acetaldehyde, acetone, and propionaldehyde were the dominant carbonyl compounds, and their concentrations were 0.034-0.170 ppm. The emission factors of carbonyl compounds were 2.10-3.70 mg g -1, and acetone, propionaldehyde, acetaldehyde, and formaldehyde accounted for a high portion of the emission factor of carbonyl compounds in essential oil exhaust. Some unhealthy carbonyl species such as formaldehyde and valeraldehyde, were measured at low-temperature during the vaporization of essential oils, indicating a potential effect on indoor air quality and human health.

  8. Prothrombin and fibrinogen carbonylation: How that can affect the blood clotting.

    Science.gov (United States)

    Harutyunyan, Hayk A

    2017-07-01

    The aim of the work was the development of a simple method for measuring the plasma prothrombin carbonylation and the study the impact of prothrombin and fibrinogen oxidation on the rate of plasma clotting. A new method was based on the ability of prothrombin to be adsorbed by the barium sulfate. It consists of four steps: prothrombin mixing with the water suspension of BaSO4; reaction of 2,4-dinitrophenylhydrazine with the BaSO4-bound prothrombin; desorption of prothrombin-2,4-dinitrophenylhydrazone complex from BaSO4 in an alkaline medium; neutralization and reading of the optical absorbance of the complex (λ = 370 nm). The prothrombin/fibrinogen carbonylation and plasma clotting rate in vitro in the presence of reactive oxygen species (ROS)-generating agents (0.05-0.8 mM Fe2+/H2O2) were monitored. The plasma volume required for measurement of carbonylated prothrombin was 0.4 ml. High level of linearity and reproducibility was observed (r = 0.9995, P = 0.0005 - for the protein; r = 0.9971, P = 0.0029 - for carbonyls). In the intact rats, the concentration of blood plasma prothrombin was 0.355 ± 0.009 mg/ml, and that of carbonyls was 4.94 ± 0.09 nmol/mg. Prothrombin and plasma clotting rate was not affected by low concentrations of ROS (0.05-0.2 mM Fe2+/H2O2). The fibrinogen was susceptible to ROS-related effect over all the used range of concentration (0.05-0.8 mM Fe2+/H2O2). Carbonylation of fibrinogen did not affect the plasma clotting activity at low ROS concentration (0.05-0.2 mM Fe2+/H2O2), however it retarded the clotting at higher ROS (0.2-0.8 mM Fe2+/H2O2).

  9. Protective effect of phenolic compounds on carbonyl-amine reactions produced by lipid-derived reactive carbonyls.

    Science.gov (United States)

    Hidalgo, Francisco J; Delgado, Rosa M; Zamora, Rosario

    2017-08-15

    The degradation of phenylalanine initiated by 2-pentenal, 2,4-heptadienal, 4-oxo-2-pentenal, 4,5-epoxy-2-heptenal, or 4,5-epoxy-2-decenal in the presence of phenolic compounds was studied to determine the structure-activity relationship of phenolic compounds on the protection of amino compounds against modifications produced by lipid-derived carbonyls. The obtained results showed that flavan-3-ols were the most efficient phenolic compounds followed by single m-diphenols. The effectiveness of these compounds was found to be related to their ability to trap rapidly the carbonyl compound, avoiding in this way the reaction of the carbonyl compound with the amino acid. The ability of flavan-3-ols for this reaction is suggested to be related to the high electronic density existing in some of the aromatic carbons of their ring A. This is the first report showing that carbonyl-phenol reactions involving lipid-derived reactive carbonyls can be produced more rapidly than carbonyl-amine reactions, therefore providing a satisfactory protection of amino compounds. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Investigation of carbonyl compound sources at a rural site in the Yangtze River Delta region of China.

    Science.gov (United States)

    Wang, Ming; Chen, Wentai; Shao, Min; Lu, Sihua; Zeng, Limin; Hu, Min

    2015-02-01

    Carbonyl compounds are important intermediates in atmospheric photochemistry, but their primary sources are still not understood well. In this work, carbonyls, hydrocarbons, and alkyl nitrates were continuously measured during November 2011 at a rural site in the Yangtze River Delta region of China. Mixing ratios of carbonyls and hydrocarbons showed large fluctuations during the entire measurement. The average level for total measured volatile organic compounds during the pollution episode from 25th to 27th November, 2011 was 91.6 ppb, about 7 times the value for the clean period of 7th-8th, November, 2011. To preliminarily identify toluene sources at this site, the emission ratio of toluene to benzene (T/B) during the pollution episode was determined based on photochemical ages derived from the relationship of alkyl nitrates to their parent alkanes. The calculated T/B was 5.8 ppb/ppb, significantly higher than the values of 0.2-1.7 ppb/ppb for vehicular exhaust and other combustion sources, indicating the dominant influence of industrial emissions on ambient toluene. The contributions of industrial sources to ambient carbonyls were then calculated using a multiple linear regression fit model that used toluene and alkyl nitrates as respective tracers for industrial emission and secondary production. During the pollution episode, 18.5%, 69.0%, and 52.9% of measured formaldehyde, acetaldehyde, and acetone were considered to be attributable to industrial emissions. The emission ratios relative to toluene for formaldehyde, acetaldehyde, and acetone were determined to be 0.10, 0.20 and 0.40 ppb/ppb, respectively. More research on industrial carbonyl emission characteristics is needed to understand carbonyl sources better. Copyright © 2014. Published by Elsevier B.V.

  11. Methane to acetic acid over Cu-exchanged zeolites: mechanistic insights from a site-specific carbonylation reaction.

    Science.gov (United States)

    Narsimhan, Karthik; Michaelis, Vladimir K; Mathies, Guinevere; Gunther, William R; Griffin, Robert G; Román-Leshkov, Yuriy

    2015-02-11

    The selective low temperature oxidation of methane is an attractive yet challenging pathway to convert abundant natural gas into value added chemicals. Copper-exchanged ZSM-5 and mordenite (MOR) zeolites have received attention due to their ability to oxidize methane into methanol using molecular oxygen. In this work, the conversion of methane into acetic acid is demonstrated using Cu-MOR by coupling oxidation with carbonylation reactions. The carbonylation reaction, known to occur predominantly in the 8-membered ring (8MR) pockets of MOR, is used as a site-specific probe to gain insight into important mechanistic differences existing between Cu-MOR and Cu-ZSM-5 during methane oxidation. For the tandem reaction sequence, Cu-MOR generated drastically higher amounts of acetic acid when compared to Cu-ZSM-5 (22 vs 4 μmol/g). Preferential titration with sodium showed a direct correlation between the number of acid sites in the 8MR pockets in MOR and acetic acid yield, indicating that methoxy species present in the MOR side pockets undergo carbonylation. Coupled spectroscopic and reactivity measurements were used to identify the genesis of the oxidation sites and to validate the migration of methoxy species from the oxidation site to the carbonylation site. Our results indicate that the Cu(II)-O-Cu(II) sites previously associated with methane oxidation in both Cu-MOR and Cu-ZSM-5 are oxidation active but carbonylation inactive. In turn, combined UV-vis and EPR spectroscopic studies showed that a novel Cu(2+) site is formed at Cu/Al <0.2 in MOR. These sites oxidize methane and promote the migration of the product to a Brønsted acid site in the 8MR to undergo carbonylation.

  12. The pollution levels of BTEX and carbonyls under haze and non-haze days in Beijing, China.

    Science.gov (United States)

    Zhang, Yujie; Mu, Yujing; Meng, Fan; Li, Hong; Wang, Xuezhong; Zhang, Weiqi; Mellouki, Abdelwahid; Gao, Jian; Zhang, Xinmin; Wang, Shulan; Chai, Fahe

    2014-08-15

    The North China Plain including Beijing is frequently suffering from serious haze days in recent years. To best recognize the influence of haze days on regional air quality, the pollution levels of deleterious gases of BTEX (benzene, toluene, ethylbenzene, m,p-xylene and o-xylene) and carbonyls (formaldehyde, acetaldehyde and acetone) under haze and non-haze days were contrastively investigated during the period of September 2008-August 2010 in Beijing. In comparison with non-haze days, remarkable enhancement of BTEX and the carbonyls under haze days in winter was found, with enhancement factors of 1.9-5.7 for BTEX and of 1.5-4.2 for the carbonyls. Whereas the enhancement factors for both BTEX (1.0-3.0) and the carbonyls (1.2-1.9) under haze days in summer were relatively small. The ratios of each BTEX to CO under both haze days and non-haze days exhibited a minimal value in the afternoon, whereas maximal values for the ratios of the carbonyls to CO were usually found in the afternoon. The ratios of each BTEX to CO were extremely greater under haze days than those under non-haze days in winter, but no evident difference was found in summer. The ratios of each carbonyl under both haze days and non-haze days in summer were at least a factor of 2 greater than those in winter and only enhancement of the ratios under haze days was found in winter. The remarkably higher ratios of ethylbenzene to m,p-xylene under haze days than non-haze days in both winter and summer revealed high reactivity of photochemical reactions initiated by OH radicals under haze days. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Characterization of Carbonyl Compounds in the Ambient Air of an Industrial City in Korea

    Directory of Open Access Journals (Sweden)

    Sung-Ok Baek

    2011-01-01

    Full Text Available The purpose of this study was to characterize spatial and temporal variations of carbonyl compounds in Gumi city, where a number of large electronic-industrial complexes are located. Carbonyl samples were collected at five sites in the Gumi area: three industrial, one commercial, and one residential area. Sampling was carried out throughout a year from December 2003 to November 2004. At one industrial site, samples were taken every six days, while those of the other sites were for seven consecutive days in every season. Each sample was collected for 150 minutes and at intervals of three times a day (morning, afternoon, and evening. A total of 476 samples were analyzed to determine 15 carbonyl compounds by the USEPA TO-11A (DNPH-cartridge/HPLC method. In general, acetaldehyde appeared to be the most abundant compound, followed by formaldehyde, and acetone+acrolein. Mean concentrations of acetaldehyde were two to three times higher in the industrial sites than in the other sites, with its maximum of 77.7 ppb. In contrast, ambient levels of formaldehyde did not show any significant difference between the industrial and non-industrial groups. Its concentrations peaked in summer probably due to the enhanced volatilization and photochemical reactivity. These results indicate significant emission sources of acetaldehyde in the Gumi industrial complexes. Mean concentrations of organic solvents (such as acetone+acrolein and methyl ethyl ketone were also significantly high in industrial areas. In conclusion, major sources of carbonyl compounds, including acetaldehyde, are strongly associated with industrial activities in the Gumi city area.

  14. Determination of Carbonyl Compounds in Exhaled Cigarette Smoke

    Directory of Open Access Journals (Sweden)

    Moldoveanu S

    2014-12-01

    Full Text Available This paper presents the findings on a quantitative evaluation of carbonyl levels in exhaled cigarette smoke from human subjects. The cigarettes evaluated include products with 5.0 mg ‘tar’, 10.6 mg ‘tar’ and 16.2 mg ‘tar’, where ‘tar’ is defined as the weight of total wet particulate matter (TPM minus the weight of nicotine and water, and the cigarettes are smoked following U.S. Federal Trade Commission (FTC recommendations. The measured levels of carbonyls in the exhaled smoke were compared with calculated yields of carbonyls in the inhaled smoke and a retention efficiency was obtained. The number of human subjects included a total of ten smokers for the 10.6 mg ‘tar’, five for the 16.2 mg ‘tar’, and five for the 5.0 mg ‘tar’ product, each subject smoking three cigarettes. The analyzed carbonyl compounds included several aldehydes (formaldehyde, acetaldehyde, acrolein, propionaldehyde, crotonaldehyde and n-butyraldehyde, and two ketones (acetone and 2-butanone. The smoke collection from the human subjects was vacuum assisted. Exhaled smoke was collected on Cambridge pads pretreated with a solution of dinitrophenylhydrazine (DNPH followed by high performance liquid chromatography (HPLC analysis of the dinitrophenylhydrazones of the carbonyl compounds. The cigarette butts from the smokers were collected and analyzed for nicotine. The nicotine levels for the cigarette butts from the smokers were used to calculate the level of carbonyls in the inhaled smoke, based on calibration curves. These were generated separately by analyzing the carbonyls in smoke and the nicotine in the cigarette butts obtained by machine smoking under different puffing regimes. The comparison of the level of carbonyl compounds in exhaled smoke with that from the inhaled smoke showed high retention of all the carbonyls. The retention of aldehydes was above 95% for all three different ‘tar’ levels cigarettes. The ketones were retained with a

  15. An alternative method for monitoring carbonyls, and the development of a 24-port fully automated carbonyl sampler for PAMS program

    Energy Technology Data Exchange (ETDEWEB)

    Parmar, S.S.; Ugarova, L. [Atmospheric Analysis and Consulting, Ventura, CA (United States); Fernandes, C.; Guyton, J.; Lee, C.P. [Arizona Dept. of Environmental Quality, Phoenix, AZ (United States)

    1994-12-31

    The authors have investigated the possibility of collecting different aldehydes and ketones on different sorbents such as silica gel, molecular sieve and charcoal followed by solvent extraction, DNPH derivatization and HPLC/UV analysis. Carbonyl collection efficiencies for these sorbents were calculated relative to a DNPH coated C{sub 18} sep-pak cartridge. From a limited number of laboratory experiments, at various concentrations, it appears that silica gel tubes can be used for sampling aldehydes (collection efficiencies {approximately} 1), whereas charcoal tubes are suitable for collecting ketones. Molecular sieve was found to be unsuitable for collecting most of the carbonyl studied. The authors also report the development of a fully automated 24-port carbonyl sampler specially designed for EPA`s PAMS program.

  16. [Defects in TOR regulatory complexes retard aging and carbonyl/oxidative stress development in yeast Saccharomyces cerevisiae].

    Science.gov (United States)

    Homza, B V; Vasyl'kovs'ka, R A; Semchyshyn, H M

    2014-01-01

    TOR signaling pathway first described in yeast S. cerevisiae is the highly conserved regulator of eukaryotic cell growth, aging and stress resistance. The effect of nitrogen sources, in particular amino acids, on the activity of TOR signaling pathway is well studied, however its relation to carbohydrates is poor understood. The aim of the present study is expanding of our understanding of potential role of TOR regulatory complexes in development of carbonyl/oxidative stress that can result from yeast cultivation on glucose and fructose. It has been shown that the level of alpha-dicarbonyl compounds and protein carbonyl groups increased with time of yeast cultivation and was higher in cells grown on fructose that demonstrated their accelerated aging and carbonyl/oxidative stress development as compared with cells grown on glucose. The strains defective in TOR proteins cultivated in the presence of glucose as well as fructose demonstrated lower markers of the stress and aging than parental strain. Thus these data confirmed the previous conclusion on fructose more potent ability to cause carbonyl/oxidative stress and accelerated aging in S. cerevisiae as compared with glucose. However, defects in TOR regulatory complexes retard aging and development of the stress in yeast independent on the type of carbohydrate in the cultivation medium.

  17. Electromagnetic properties of carbonyl iron and their microwave ...

    Indian Academy of Sciences (India)

    Administrator

    Abstract. The complex permittivity, permeability and microwave-absorbing properties of rubber composites filled with carbonyl iron are measured at frequencies from 2–18 GHz. The results indicate that the reflection loss peak shifts towards low frequency region with increasing layer thickness or increasing weight concentra-.

  18. Carbonyl Sulfide Isotopologues: Ultraviolet Absorption Cross Sections and Stratospheric Photolysis

    DEFF Research Database (Denmark)

    Danielache, Sebastian Oscar; Nanbu, Shinkoh; Eskebjerg, Carsten

    2009-01-01

    Ultraviolet absorption cross sections of the main and substituted carbonyl sulfide isotopologues were calculated using wavepacket dynamics. The calculated absorption cross section of 16O12C32S is in very good agreement with the accepted experimental spectrum between 190 and 250 nm. Relative to 16O...

  19. Sampling And Analysis Of Carbonyl In Laboratory Atmospheres ...

    African Journals Online (AJOL)

    A sampling and analytical method has been developed for carbonyl concentrations in different laboratory atmospheres at the faculty of Science Bayero University; Kano, Nigeria using cold oximation followed by titrimetric finish. The analysis was carried out between 008 and 1800 hrs from from October 2002 to June 2003.

  20. Cytokinin inhibits the proteasome-mediated degradation of carbonylated proteins in Arabidopsis leaves

    Science.gov (United States)

    Under normal conditions, plants contain numerous carbonylated proteins, which are thought to be indicative of oxidative stress damage. Conditions that promote formation of reactive oxygen species (ROS) enhance protein carbonylation, and protein degradation is required to reverse the damage. However,...

  1. Degradation of carbonyl hydroperoxides in the atmosphere and in combustion

    KAUST Repository

    Xing, Lili

    2017-10-12

    Oxygenates with carbonyl and hydroperoxy functional groups are important intermediates that are generated during the autooxidation of organic compounds in the atmosphere and during the autoignition of transport fuels. In the troposphere, the degradation of carbonyl hydroperoxides leads to low-vapor-pressure polyfunctional species that be taken into in cloud and fog droplets or to the formation of secondary organic aerosols (SOAs). In combustion, the fate of carbonyl hydroperoxides is important for the performance of advanced combustion engines, especially for autoignition. A key fate of the carbonyl hydroperoxides is reac-tion with OH radicals, for which kinetics data are experimentally unavailable. Here, we study 4-hydroperoxy-2-pentanone (CH3C(=O)CH2CH(OOH)CH3) as a model compound to clarify the kinetics of OH reactions with carbonyl hydroperoxides, in par-ticular H-atom abstraction and OH addition reactions. With a combination of electronic structure calculations, we determine previ-ously missing thermochemical data, and with multipath variational transition state theory (MP-VTST), a multidimensional tunnel-ing (MT) approximation, multiple-structure anharmonicity, and torsional potential anharmonicity we obtained much more accurate rate constants than the ones that can computed by conventional single-structure harmonic transition state theory (TST) and than the empirically estimated rate constants that are currently used in atmospheric and combustion modeling. The roles of various factors in determining the rates are elucidated. The pressure-dependent rate constants for the addition reaction are computed using system-specific quantum RRK theory. The calculated temperature range is 298-2400 K, and the pressure range is 0.01–100 atm. The accu-rate thermodynamic and kinetics data determined in this work are indispensable in the global modeling of SOAs in atmospheric science and in the detailed understanding and prediction of ignition properties of hydrocarbons

  2. High-resolution X-ray absorption spectroscopy of iron carbonyl complexes

    OpenAIRE

    Atkins, A.J.; Bauer, M; Jacob, C.R.

    2015-01-01

    We apply high-energy-resolution fluorescence-detected (HERFD) X-ray absorption near-edge spectroscopy (XANES) to study iron carbonyl complexes. Mono-, bi-, and tri-nuclear carbonyl complexes and pure carbonyl complexes as well as carbonyl complexes containing hydrocarbon ligands are considered. The HERFD-XANES spectra reveal multiple pre-edge peaks with individual signatures for each complex, which could not be detected previously with conventional XANES spectroscopy. These peaks are assigned...

  3. Optimized biotin-hydrazide enrichment and mass spectrometry analysis of peptide carbonyls

    DEFF Research Database (Denmark)

    Havelund, Jesper F.; Wojdyla, K; Jensen, O. N.

    is an important piece of information in this puzzle. Mass spectrometry is here a superior tool; however, protein/peptide carbonylation is of low stoichiometry and the MS signal is decreased due to low ionization efficiency and signal suppression from non-modified peptides. In addition, other more common...... modifications are isobaric to carbonylation and it is often challenging to detect the weaker signal from carbonylated peptides necessitating enrichment step. We here present an optimized method for the enrichment of carbonylated peptides....

  4. Elevated protein carbonylation and oxidative stress do not affect protein structure and function in the long-living naked-mole rat: a proteomic approach.

    Science.gov (United States)

    De Waal, Eric M; Liang, Hanyu; Pierce, Anson; Hamilton, Ryan T; Buffenstein, Rochelle; Chaudhuri, Asish R

    2013-05-17

    The 'oxidative stress theory of aging' predicts that aging is primarily regulated by progressive accumulation of oxidized macromolecules that cause deleterious effects to cellular homeostasis and induces a decline in physiological function. However, our reports on the detection of higher level of oxidized protein carbonyls in the soluble cellular fractions of long-living rodent naked-mole rats (NMRs, lifespan ~30yrs) compared to short-lived mice (lifespan ~3.5yrs) apparently contradicts a key tenet of the oxidative theory. As oxidation often inactivates enzyme function and induces higher-order soluble oligomers, we performed a comprehensive study to measure global protein carbonyl level in different tissues of age-matched NMRs and mice to determine if the traditional concept of oxidation mediated impairment of function and induction of higher-order structures of proteins are upheld in the NMRs. We made three intriguing observations with NMRs proteins: (1) protein carbonyl is significantly elevated across different tissues despite of its exceptional longevity, (2) enzyme function is restored despite of experiencing higher level of protein carbonylation, and (3) enzymes show lesser sensitivity to form higher-order non-reducible oligomers compared to short-living mouse proteins in response to oxidative stress. These observations were made based on the global analysis of protein carbonyl and identification of two heavily carbonylated proteins in the kidney, triosephosphate isomerase (TPI) and cytosolic peroxiredoxin (Prdx1). These un-expected intriguing observations thus strongly suggest that oxidative modification may not be the only criteria for impairment of protein and enzyme function; cellular environment is likely be the critical determining factor in this process and may be the underlying mechanism for exceptional longevity of NMR. Copyright © 2013 Elsevier Inc. All rights reserved.

  5. Cesium Carbonate-Catalyzed α-Phenylchalcogenation of Carbonyl Compounds with Diphenyl Dichalcogenide

    Directory of Open Access Journals (Sweden)

    Yutaka Nishiyama

    2009-09-01

    Full Text Available It was found that cesium carbonate has a unique catalytic ability on the reaction of carbonyl compounds with diphenyl diselenide to give the corresponding α-phenylseleno carbonyl compounds in moderate to good yields. Similarly, the α-phenylthiolation of carbonyl compounds with diphenyl disulfide was promoted by the cesium carbonate catalyst.

  6. Deep-blue phosphorescence from perfluoro carbonyl-substituted iridium complexes.

    Science.gov (United States)

    Lee, Sunghun; Kim, Seul-Ong; Shin, Hyun; Yun, Hui-Jun; Yang, Kiyull; Kwon, Soon-Ki; Kim, Jang-Joo; Kim, Yun-Hi

    2013-09-25

    The new deep-blue iridium(III) complexes, (TF)2Ir(pic), (TF)2Ir(fptz), (HF)2Ir(pic), and (HF)2Ir(fptz), consisting of 2',4″-difluororphenyl-3-methylpyridine with trifluoromethyl carbonyl or heptafluoropropyl carbonyl at the 3' position as the main ligand and a picolinate or a trifluoromethylated-triazole as the ancillary ligand, were synthesized and characterized for applications in organic light-emitting diodes (OLEDs). Density function theory (DFT) calculations showed that these iridium complexes had a wide band gap, owing to the introduction of the strong electron withdrawing perfluoro carbonyl group. Time-dependent DFT (TD-DFT) calculations suggested that their lowest triplet excited state was dominated by a HOMO → LUMO transition and that the contribution of the metal-to-ligand charge transfer (MLCT) was higher than 34% for all four complexes, indicating that strong spin-orbit coupling exists in the complexes. The 10 wt % (TF)2Ir(pic) doped 9-(3-(9H-carbazole-9-yl)phenyl)-3-(dibromophenylphosphoryl)-9H-carbazole (mCPPO1) film exhibited the highest photoluminescence quantum yield of 74 ± 3% among the films based on the four complexes. Phosphorescent OLEDs based on (TF)2Ir(pic) and (TF)2Ir(fptz) exhibited maximum external quantum efficiencies of 17.1% and 8.4% and Commission Internationale de l'Eclairage (CIE) coordinates of (0.141, 0.158) and (0.147, 0.116), respectively. These CIE coordinates represent some of the deepest blue emissions ever achieved from phosphorescent OLEDs with considerably high EQEs.

  7. Role of Carbonyl Modifications on Aging-Associated Protein Aggregation

    Science.gov (United States)

    Tanase, Maya; Urbanska, Aleksandra M.; Zolla, Valerio; Clement, Cristina C.; Huang, Liling; Morozova, Kateryna; Follo, Carlo; Goldberg, Michael; Roda, Barbara; Reschiglian, Pierluigi; Santambrogio, Laura

    2016-01-01

    Protein aggregation is a common biological phenomenon, observed in different physiological and pathological conditions. Decreased protein solubility and a tendency to aggregate is also observed during physiological aging but the causes are currently unknown. Herein we performed a biophysical separation of aging-related high molecular weight aggregates, isolated from the bone marrow and splenic cells of aging mice and followed by biochemical and mass spectrometric analysis. The analysis indicated that compared to younger mice an increase in protein post-translational carbonylation was observed. The causative role of these modifications in inducing protein misfolding and aggregation was determined by inducing carbonyl stress in young mice, which recapitulated the increased protein aggregation observed in old mice. Altogether our analysis indicates that oxidative stress-related post-translational modifications accumulate in the aging proteome and are responsible for increased protein aggregation and altered cell proteostasis.

  8. Metal Carbonyl-Hydrosilane Reactions and Hydrosilation Catalysis

    Energy Technology Data Exchange (ETDEWEB)

    Cutler, A. R.

    2001-04-14

    Manganese carbonyl complexes serve as hydrosilation precatalysts for selectively transforming a carbonyl group into a siloxy methylene or a fully reduced methylene group. Substrates of interest include (1) aldehydes, ketones, carboxylic acids, silyl esters, and esters, and (2) their organometallic acyl counterparts. Three relevant catalytic reactions are shown. Two types of manganese precatalysts have been reported: (a) alkyl and acyl complexes (L)(C0){sub 4}MnR [L = CO, PPh{sub 3}; R = COCH{sub 3}, COPh, CH{sub 3}] and (b) halides (CO){sub 5}MnX and [(CO){sub 4}MnX]{sub 2} (X = Br, I). The former promote hydrosilation and deoxygenation catalysis; the latter promote dehydrogenative silation of alcohols and carboxylic acids as well as hydrosilation and deoxygenation of some metallocarboxylic acid derivatives. In every case studied, these Mn precatalysts are far more reactive or selective than traditional Rh(I) precatalysts.

  9. Nucleophilic tetrafluoroethylation of carbonyl compounds with fluorinated sulfones

    Czech Academy of Sciences Publication Activity Database

    Václavík, Jiří; Chernykh, Yana; Jurásek, Bronislav; Beier, Petr

    2015-01-01

    Roč. 169, Jan (2015), s. 24-31 ISSN 0022-1139 R&D Projects: GA ČR GAP207/11/0421 Grant - others:GA MŠk(CZ) ED3.2.00/08.0144; GA MŠk(CZ) LM2010005 Institutional support: RVO:61388963 Keywords : fluorine * tetrafluoroethylation * sulfones * nucleophilic addition * carbonyl compounds Subject RIV: CC - Organic Chemistry Impact factor: 2.213, year: 2015

  10. Carbonyl-Phenol Adducts: An Alternative Sink for Reactive and Potentially Toxic Lipid Oxidation Products.

    Science.gov (United States)

    Zamora, Rosario; Hidalgo, Francisco J

    2018-02-14

    Different from the well-characterized function of phenolics as antioxidants, their function as lipid-derived carbonyl scavengers is mostly unknown. However, phenolics react with lipid-derived carbonyls as a function of the nucleophilicity of their reactive groups and the electronic effects and steric hindrances present in the reactive carbonyls. Furthermore, the reaction produces a wide variety of carbonyl-phenol adducts, some of which are stable and have been isolated and characterized but others polymerize spontaneously. This perspective updates present knowledge about the lipid-derived carbonyl trapping ability of phenolics, its competition with carbonyl-amine reactions produced in foods, and the presence of carbonyl-phenol adducts in food products.

  11. Carbonylation and glutathionylation of proteins in the blue mussel Mytilus edulis detected by proteomic analysis and Western blotting: Actin as a target for oxidative stress.

    Science.gov (United States)

    McDonagh, Brian; Tyther, Raymond; Sheehan, David

    2005-07-01

    Protein expression profiles (PEPs) were generated by two-dimensional electrophoresis (2-D SDS-PAGE) for gill and digestive glands of Mytilus edulis sampled from a polluted and reference site in Cork Harbour, Ireland. Similar patterns and expression levels were found for both sites in silver stained gels. However, Western blotting for carbonylated proteins demonstrated higher levels of specific carbonylation of proteins in tissues from animals in the polluted site. Animals from the reference site were acclimated in holding tanks, exposed to 1 mM H2O2 for 24 h, dissected and analysed by 2-D SDS-PAGE. Again, generally similar PEPs were found in control and exposed animals for gill and digestive gland but carbonylation was more pronounced in polluted and exposed animals. Western blotting of extracts after one-dimensional electrophoresis with antibodies to glutathione and actin revealed that gill proteins are glutathionylated more strongly than digestive gland and that this process is more pronounced in polluted animals than in controls. We conclude that carbonylation and glutathionylation can occur in gill and digestive gland in response to oxidative stress in M. edulis. Actin is a major target for both glutathionylation and carbonylation under oxidative stress conditions.

  12. Iron(III)-catalysed carbonyl-olefin metathesis

    Science.gov (United States)

    Ludwig, Jacob R.; Zimmerman, Paul M.; Gianino, Joseph B.; Schindler, Corinna S.

    2016-05-01

    The olefin metathesis reaction of two unsaturated substrates is one of the most powerful carbon-carbon-bond-forming reactions in organic chemistry. Specifically, the catalytic olefin metathesis reaction has led to profound developments in the synthesis of molecules relevant to the petroleum, materials, agricultural and pharmaceutical industries. These reactions are characterized by their use of discrete metal alkylidene catalysts that operate via a well-established mechanism. While the corresponding carbonyl-olefin metathesis reaction can also be used to construct carbon-carbon bonds, currently available methods are scarce and severely hampered by either harsh reaction conditions or the required use of stoichiometric transition metals as reagents. To date, no general protocol for catalytic carbonyl-olefin metathesis has been reported. Here we demonstrate a catalytic carbonyl-olefin ring-closing metathesis reaction that uses iron, an Earth-abundant and environmentally benign transition metal, as a catalyst. This transformation accommodates a variety of substrates and is distinguished by its operational simplicity, mild reaction conditions, high functional-group tolerance, and amenability to gram-scale synthesis. We anticipate that these characteristics, coupled with the efficiency of this reaction, will allow for further advances in areas that have historically been enhanced by olefin metathesis.

  13. Fluorimetric screening assay for protein carbonyl evaluation in biological samples.

    Science.gov (United States)

    Stocker, P; Ricquebourg, E; Vidal, N; Villard, C; Lafitte, D; Sellami, L; Pietri, S

    2015-08-01

    Many assays are available for the detection of protein carbonyls (PCs). Currently, the measurement of PC groups after their derivatization with 2,4-dinitrophenol hydrazine (DNPH) is widely used for measuring protein oxidation in biological samples. However, this method includes several washing steps. In this context, we have developed a rapid, sensitive, and accurate fluorimetric method adapted to 96-well microplates for the convenient assessment of protein carbonyl level in biological samples. The method reported here is based on the reaction of carbonyl content in proteins with 7-hydrazino-4-nitrobenzo-2,1,3-oxadiazole (NBDH) to form highly fluorescent derivatives via hydrazone formation. PCs were determined using the DNPH and NBDH assays in fully reduced bovine serum albumin (BSA) and plasma and liver homogenates obtained from healthy control rats up the addition of various amounts of HOCl-oxidized BSA (OxBSA). Using the NBDH assay, PC concentrations as low as 0.2 nmol/mg were detected with precision as low as 5%. Matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectroscopy was used to successfully identify the formation of the NBDH adducts after derivatization with standard oxidized peptides. Finally, the two methods were further used for PC determination in plasma and liver samples from diabetic and normal rats, showing that the NBDH assay can be reliably used in biological experiments. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. Carbonylation of Ethene Catalysed by Pd(II-Phosphine Complexes

    Directory of Open Access Journals (Sweden)

    Gianni Cavinato

    2014-09-01

    Full Text Available This review deals with olefin carbonylation catalysed by Pd(II-phosphine complexes in protic solvents. In particular, the results obtained in the carbonylation with ethene are reviewed. After a short description of the basic concepts relevant to this catalysis, the review treats in greater details the influence of the bite angle, skeletal rigidity, electronic and steric bulk properties of the ligand on the formation of the products, which range from high molecular weight perfectly alternating polyketones to methyl propanoate. It is shown that the steric bulk plays a major role in directing the selectivity. Particular emphasis is given to the factors governing the very active and selective catalysis to methyl propanoate, including the mechanism of the catalytic cycles with diphosphine- and monophosphine-catalysts. A brief note on the synthesis of methyl propanoate using a “Lucite” type catalyst in ionic liquids is also illustrated. A chapter is dedicated to the carbonylation of olefins in aqueous reaction media. The nonalternating CO-ethene copolymerization is also treated.

  15. Behavior of VOCs and carbonyl compounds emission from different types of wallpapers in Korea.

    Science.gov (United States)

    Lim, Jungyun; Kim, Suejin; Kim, Arong; Lee, Wooseok; Han, Jinseok; Cha, Jun-Seok

    2014-04-17

    Emissions of volatile organic compounds (VOCs) and carbonyls from three types of commercially available wallpapers (i.e., PVC-coated, paper-backed, natural material-coated) in Korea were evaluated using a 20 L small chamber. A total of 332 products were tested for emission factors, frequencies of occurrence and composition ratios. Toluene and formaldehyde concentrations were below Korean standard values for all products; however, the total VOC (TVOC) concentrations exceeded current standards (4.0 mg/m²·h) for 30 products. The TVOC emission factor for PVC-coated wallpapers, for which polymer materials are used in the manufacturing process, was seven and 16 times higher than those of paper-backed and natural material-coated wallpapers, respectively. The detection frequencies for toluene and formaldehyde were the highest (82.5%) and fourth highest (79.5%), respectively among the 50 target chemical species. The composition ratios for BTEX ranged from 0.3% to 5.1% and unidentified VOCs, which were not qualitatively analyzed using standard gas methods, ranged from 90.2% to 94.8%. Among six carbonyl compounds (acrolein was not detected in any type of wallpaper), acetone had the highest concentrations in PVC-coated (44.6%) and paper-backed (66.6%) wallpapers. Formaldehyde emissions were highest (64.6%) for natural material-coated wallpapers, a result of the formaldehyde-based resin used in the manufacturing process for these products.

  16. Enhanced microwave absorbing properties and heat resistance of carbonyl iron by electroless plating Co

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hongyu, E-mail: wanghongyu07010310@163.com; Zhu, Dongmei; Zhou, Wancheng; Luo, Fa

    2015-11-01

    Co coated carbonyl iron particles (Co (CI)) are fabricated through electroless plating method, and the electromagnetic microwave absorbing properties are investigated in the frequencies during 8.2–12.4 GHz. The complex permittivity of CI particles after electroless plating Co is higher than that of raw CI particles due to improvment of the polarization process. Furthermore, according to the XRD and TG results, the Co layer can enhance the heat resistance of CI particles. The bandwidth below −10 dB can reach 3.9 GHz for the Co(CI) absorbent. The results indicate that the electroless plating Co not only enhances the absorbing properties but also improves the heat resistance of CI. - Highlights: • The Co-coated carbonyl iron Co(CI) particles were prepared by electroless plating. • The electromagnetic wave absorbing properties of Co(CI) particles were studied. • The heat treatment on the absorbing property of Co(CI) particles was studied. • The Co(CI) particles have good absorbing property when compared with CI.

  17. [Chemical Characteristics and Sources of Atmospheric Carbonyls During the 2014 Beijing APEC].

    Science.gov (United States)

    He, Xiao-lang; Tan, Ji-hua; Guo, Song-jun; Ma, Yong-liang; He, Ke-bin

    2016-03-15

    Pollution characteristic and variation trend of atmospheric carbonyls were investigated in November during the 2014 Beijing APEC. Formaldehyde, acetaldehyde and acetone were the dominant carbonyls, accounting for 82.66% of total carbonyls, and especially, formaldehyde accounted for 40.12% of total carbonyls. Atmospheric concentrations of total carbonyls decreased by around 64.10% after the clean air policy was carried out during the Beijing APEC, and the variation trend of carbonyls showed a similar pattern to those of other pollutants like PM₂.₅ during the APEC. Strong correlations (R² of 0.67-0.98) were observed among formaldehyde, acetaldehyde, acetone and total carbonyls during and after the APEC, indicating that they had similar sources; however, poor correlations (R² of -0.11-0.42 and 0.16-0.94, respectively) were observed before the APEC, implying different emission sources for ambient carbonyls. The calculated ratios of C1/C2, C2/C3 and OC/EC indicated that both vehicles and coal emissions were responsible for atmospheric carbonyls before the APEC, and emissions from coal burning were the major contributor to atmospheric carbonyls during and after the APEC, especially after the APEC.

  18. Nanostructure Fabrication by Electron-Beam-Induced Deposition with Metal Carbonyl Precursor and Water Vapor

    Science.gov (United States)

    Takeguchi, Masaki; Shimojo, Masayuki; Furuya, Kazuo

    2007-09-01

    Nanorod fabrication is performed by electron beam induced deposition (EBID) with iron carbonyl [Fe(CO)5] and tungsten carbonyl [W(CO)6] precursors. The effects of water vapor addition to each metal carbonyl on the microstructure and composition of the obtained nanorods are studied. Normally, EBID-fabricated metal nanorods consist of an amorphous phase containing a considerable amount of carbon. However, it is found that water vapor addition to iron carbonyl can effectively reduce the carbon content of the nanorods and induce the formation of carbon-free crystalline Fe3O4 nanorods with increasing partial pressure ratio of water vapor to iron carbonyl. In contrast, for tungsten carbonyl, water vapor addition has no obvious effect on carbon content reduction. The obtained nanorods consist of a carbon-rich amorphous matrix containing tungsten oxide nanocrystals inside.

  19. Frustrated Lewis pairs-assisted reduction of carbonyl compounds

    DEFF Research Database (Denmark)

    Marek, Ales; Pedersen, Martin Holst Friborg

    2015-01-01

    An alternative and robust method for the reduction of carbonyl groups by frustrated Lewis pairs (FLPs) is reported in this paper. With its very mild reaction conditions, good to excellent yields, absolute regioselectivity and the non-metallic character of the reagent, it provides an excellent tool...... for H-1, H-2 as well as H-3 chemistry. It is a new strategy for the one-pot synthesis of aromatic alcohols selectively labeled with heavy isotopes of hydrogen. © 2015 Elsevier Ltd. All rights reserved....

  20. A biotin enrichment strategy identifies novel carbonylated amino acids in proteins from human plasma

    DEFF Research Database (Denmark)

    Havelund, Jesper F.; Wojdyla, Katarzyna; Davies, Michael J.

    2017-01-01

    Protein carbonylation is an irreversible protein oxidation correlated with oxidative stress, various diseases and ageing. Here we describe a peptide-centric approach for identification and characterisation of up to 14 different types of carbonylated amino acids in proteins. The modified residues...... in vitro metal ion-catalysed oxidation. Furthermore, we assigned 133 carbonylated sites in 36 proteins in native human plasma protein samples. The optimised workflow enabled detection of 10 hitherto undetected types of carbonylated amino acids in proteins: aldehyde and ketone modifications of leucine...

  1. Serum levels of carbonylated and nitrosylated proteins in mobbing victims with workplace adjustment disorders.

    Science.gov (United States)

    Di Rosa, A E; Gangemi, S; Cristani, M; Fenga, C; Saitta, S; Abenavoli, E; Imbesi, S; Speciale, A; Minciullo, P L; Spatari, G; Abbate, S; Saija, A; Cimino, F

    2009-12-01

    Today the most important problem in the work place is psychological abuse, which may affect the health because of high levels of stress and anxiety. There is evidence that most psychiatric disorders are associated with increased oxidative stress but nothing is reported about the presence of oxidative stress in mobbing victims. This study has been carried out in a group of 19 patients affected by workplace mobbing-due adjustment disorders, in comparison with 38 healthy subjects, to evaluate whether oxidative stress may be induced by mobbing. Serum levels of protein carbonyl groups and of nitrosylated proteins, biological markers of oxidative stress conditions, were higher than those measured in healthy subjects. These findings may contribute to a better understanding of the redox homeostasis dysregulation occurring in victims of workplace mobbing.

  2. Carbonyl iron based magnetorheological effects with silver nanoparticles via green-assisted coating

    Science.gov (United States)

    Hajalilou, Abdollah; Kianvash, Abbas; Shameli, Kamyar; Lavvafi, Hossein

    2017-06-01

    Carbonyl iron (CI) particles are widely used in magnetorheological (MR) fluids due to their excellent magnetic properties, i.e., high saturation magnetization and low coercivity. However, pristine CI-based MR fluids have major shortcomings, which restrict their applications: abrasion of device surfaces during operation, redispersion difficulties after caking, iron oxidation, and severe sedimentation of CI particles due to higher density compared to the carrier liquid. As a remedy, the CI particles were coated with Ag shell by green-assisted method and stabilized with honey. The CI and CI-Ag particles were separately dispersed in Polyalphaolefin (PAO) oil, and the subsequent rheological effects were evaluated. Although the MR effects, e.g., yield stress and shear viscosity of CI-Ag-based MR fluids, varied slightly compared to the original one, the dispersion qualities, e.g., sedimentation stability, were remarkably improved.

  3. Enhanced magnetorheological response of magnetic chromium dioxide nanoparticle added carbonyl iron suspension

    Science.gov (United States)

    Kim, Min Hwan; Choi, Kisuk; Do Nam, Jae; Choi, Hyoung Jin

    2017-09-01

    Hard-magnetic chromium dioxide nanoparticles with a rod-like shape were introduced as an additive to a soft-magnetic carbonyl iron (CI)-based magnetorheological (MR) fluid. The magnetic stimuli-response of the MR fluid in terms of the steady shear and dynamic oscillation tests was examined using a rotational rheometer. While the Bingham fluid model fitted the flow curves, the dynamic yield stress followed the universal yield stress scale function quite well. Compared to the CI-based MR fluid without chromium dioxide nanoparticles, the MR fluid with the chromium dioxide additive exhibited remarkably higher yield behavior with increasing magnetic field strength, enhancing its MR performance and dispersion stability.

  4. Anomalous Behavior Observed upon Annealing and Photodetachment of Anionic Copper Carbonyl Clusters in Argon Matrices

    Science.gov (United States)

    Ludwig, Ryan M.; Moore, David T.

    2014-06-01

    Using matrix isolation FTIR, we have observed the formation of anionic copper carbonyl complexes [Cu(CO)n]- (n=1-3) following co-deposition of Cu- and counter-cations (Ar+ or Kr+) into argon matrices doped with CO. When the deposition is carried out at 20 K, weak bands corresponding to the neutral copper carbonyl complexes Cu(CO)n (n=1-3) are also observed, and these grow in steadily as the matrix is annealed up to 30 K. This is in contrast to what is observed at 10 K (c.f. ISMS 2014 abstract #P631), where no appreciable neutral bands are observed, and indicates that some neutralization occurs during the formation of the complexes in the 20 K matrix. In addition, sharp peaks not previously observed grow in around the anionic bands upon annealing to 30 K; this is somewhat odd, since annealing typically simplifies the spectra of matrix samples as kinetically trapped metastable species relax to more stable forms. In this case, higher-resolution (0.125 wn) spectra reveal considerable new fine structure, with 5 and 20 peaks appearing in the regions of the mono- and tricarbonyl anions, respectively, each of which nominally has but a single IR-active CO-stretching mode. These new features are tentatively assigned (at least in part) to electric-field-induced splitting arising from long-range interactions with cationic species in the matrix. A second anomalous feature of these spectra is that, upon photodetachment, several new bands are observed in the region of the neutral copper carbonyl species. Upon annealing these bands then disappear, with concomitant growth of the expected neutral bands. This behavior raises the exciting possibility that these transient bands represent metastable "vertical detachment products", where the neutral species has been kinetically trapped by the matrix in the geometry of the anion. Evidence supporting this interpretation will be presented. Funding support from NSF CAREER Award CHE-0955637 is gratefully acknowledged Ryan M. Ludwig and David

  5. Iron(III)-Catalyzed Ring-Closing Carbonyl-Olefin Metathesis.

    Science.gov (United States)

    Saá, Carlos

    2016-09-05

    Recent developments in catalytic carbonyl-olefin metathesis are summarized in this Highlight. Schindler and co-workers have reported that the environmentally benign FeCl3 catalyst promotes ring-closing carbonyl-olefin metathesis (RCCOM) in high yield under very mild conditions. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Ketene as a Reaction Intermediate in the Carbonylation of Dimethyl Ether to Methyl Acetate over Mordenite

    DEFF Research Database (Denmark)

    Rasmussen, Dominik Bjørn; Christensen, Jakob Munkholt; Temel, Burcin

    2015-01-01

    Unprecedented insight into the carbonylation of dimethyl ether over Mordenite is provided through the identification of ketene (CH2CO) as a reaction intermediate. The formation of ketene is predicted by detailed DFT calculations and verified experimentally by the observation of doubly deuterated ...... acetic acid (CH2DCOOD), when D2O is introduced in the feed during the carbonylation reaction....

  7. VizieR Online Data Catalog: Millimeter wave spectra of carbonyl cyanide (Bteich+, 2016)

    Science.gov (United States)

    Bteich, S. B.; Tercero, B.; Cernicharo, J.; Motiyenko, R. A.; Margules, L.; Guillemin, J.-C.

    2016-05-01

    Table 3 contains assigned rotational transitions of the ground state and the first excited vibrational state (v5=1) of carbonyl cyanide. Table 4 contains predicted transitions of the ground vibrational state of carbonyl cyanide in the frequency range up to 1THz. (2 data files).

  8. Defects in tor regulatory complexes retard aging and carbonyl/oxidative stress development in yeast Sассharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    B. V. Homza

    2014-02-01

    Full Text Available TOR signaling pathway first described in yeast S. сerevisiae is the highly conserved regulator of eukaryotic cell growth, aging and stress resistance. The effect of nitrogen sources, in particular amino acids, on the activity of TOR signaling pathway is well studied, however its relation to carbohydrates is poor understood. The aim of the present study is expanding of our understanding of potential role of TOR regulatory complexes in development of carbonyl/oxidative stress that can result from yeast cultivation on glucose and fructose. It has been shown that the level of α-dicarbonyl compounds and protein carbonyl groups increased with time of yeast cultivation and was higher in cells grown on fructose that demonstrated their accelerated aging and carbonyl/oxidative stress development as compared with cells grown on glucose. The strains defective in TOR proteins cultivated in the presence of glucose as well as fructose demonstrated lower markers of the stress and aging than parental strain. Thus these data confirmed the previous conclusion on fructose more potent ability to cause carbonyl/oxidative stress and accelerated aging in S. cerevisiae as compared with glucose. However, defects in TOR regulatory complexes retard aging and development of the stress in yeast independent on the type of carbohydrate in the cultivation medium.

  9. High-resolution X-ray absorption spectroscopy of iron carbonyl complexes.

    Science.gov (United States)

    Atkins, Andrew J; Bauer, Matthias; Jacob, Christoph R

    2015-06-07

    We apply high-energy-resolution fluorescence-detected (HERFD) X-ray absorption near-edge spectroscopy (XANES) to study iron carbonyl complexes. Mono-, bi-, and tri-nuclear carbonyl complexes and pure carbonyl complexes as well as carbonyl complexes containing hydrocarbon ligands are considered. The HERFD-XANES spectra reveal multiple pre-edge peaks with individual signatures for each complex, which could not be detected previously with conventional XANES spectroscopy. These peaks are assigned and analysed with the help of TD-DFT calculations. We demonstrate that the pre-edge peaks can be used to distinguish the different types of iron-iron interactions in carbonyl complexes. This opens up new possibilities for applying HERFD-XANES spectroscopy to probe the electronic structure of iron catalysts.

  10. Rapid method for determination of carbonyl groups in lignin compounds by headspace gas chromatography.

    Science.gov (United States)

    Li, Jing; Hu, Hui-Chao; Chai, Xin-Sheng

    2015-07-24

    The paper reports on a novel method for rapid determination of carbonyl in lignins by headspace gas chromatography (HS-GC). The method involves the quantitative carbonyl reduction for aldehydes in 2min at room temperature or for acetones in 30min at 80°C by sodium borohydride solution in a closed headspace sample vial. After the reaction, the solution was acidified by injecting sulfuric acid solution and the hydrogen released to the headspace was determined by GC using thermal-conductivity detector. The results showed that with the addition of SiO2 powder, the reduction reaction of carbonyl groups can be greatly facilitated. The method has a good measurement precision (RSD<7.74%) and accuracy (relative error <10% compared with a reference method) in the carbonyl quantification. It is suitable to be used for rapid determination of carbonyl content in lignin and related materials. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Protein carbonylation and metal-catalyzed protein oxidation in a cellular perspective

    DEFF Research Database (Denmark)

    Møller, Ian Max; Rogowska-Wrzesinska, Adelina; Rao, Shyama Prasad

    2011-01-01

    Proteins can become oxidatively modified in many different ways, either by direct oxidation of amino acid side chains and protein backbone or indirectly by conjugation with oxidation products of polyunsaturated fatty acids and carbohydrates. While reversible oxidative modifications are thought...... to be relevant in physiological processes, irreversible oxidative modifications are known to contribute to cellular damage and disease. The most well-studied irreversible protein oxidation is carbonylation. In this work we first examine how protein carbonylation occurs via metal-catalyzed oxidation (MCO) in vivo...... and in vitro with an emphasis on cellular metal ion homeostasis and metal binding. We then review proteomic methods currently used for identifying carbonylated proteins and their sites of modification. Finally, we discuss the identified carbonylated proteins and the pattern of carbonylation sites in relation...

  12. Influência da estrutura de diferentes copolímeros de etileno e a-olefinas na funcionalização com anidrido maleico Influence of structure of ethylene a-olefins copolymers in functionalization with maleic anhydride

    Directory of Open Access Journals (Sweden)

    Carlota H. F. Maurano

    1998-01-01

    Full Text Available A funcionalização de copolímeros de etileno e a-olefinas com anidrido maleico (AM foi realizada em solução de xileno com peróxido de dibenzoíla (DBP como iniciador. Foi estudado o efeito das diferentes estruturas dos copolímeros, como número e comprimento de ramificação, na incorporação do AM. A funcionalização também foi realizada em estado fundido utilizando-se um misturador Rheomix 600 e uma extrusora Rheocord 9000 da Haake. A funcionalidade foi determinada por titulometria de neutralização e os produtos foram caracterizados por espectroscopia na região do infravermelho (FT-IR e por cromatografia de permeação em gel (GPC. A funcionalidade dos copolímeros de etileno com 1-hexeno aumentou com o aumento do teor de comonômero e dos copolímeros com 1-octeno e 1-deceno aumentou com o aumento do teor de a-olefina até um máximo, decrescendo e mantendo-se constante.Chemical modification of ethylene a-olefins copolymers with maleic anhydride was studied by radical reaction in solution, melt mixing and extrusion. The effect of copolymer structure, as the amount and length of the branches, was evaluated on the MA incorporation. The reactions were also achieved in Rheomix 600 (Haake mixer and Rheocord 9000 (Haake extruder. Functionalization was determinated by titration and modified ethylene a-olefins copolymers were characterized by Infrared Spectroscopy and Gel Permeation Chromatography. The maleic anhydride incorporation in the ethylene-hexene copolymers increases with the amount of a-olefin. Functionalization of ethylene-octene and ethylene-decene comonomers increases with increasing peroxide concentration until a maximum and then decreases up to a constant value.

  13. Protein carbonylation sites in bovine raw milk and processed milk products.

    Science.gov (United States)

    Milkovska-Stamenova, Sanja; Mnatsakanyan, Ruzanna; Hoffmann, Ralf

    2017-08-15

    During thermal treatment of milk, proteins are oxidized, which may reduce the nutritional value of milk, abolish protein functions supporting human health, especially important for newborns, and yield potentially harmful products. The side chains of several amino acids can be oxidized to reactive carbonyls, which are often used to monitor oxidative stress in organisms. Here we mapped protein carbonylation sites in raw milk and different brands of pasteurized, ultra high temperature (UHT) treated milk, and infant formulas (IFs) after digesting the precipitated proteins with trypsin. Reactive carbonyls were derivatized with O-(biotinylcarbazoylmethyl)hydroxylamine to enrich the modified peptides by avidin-biotin affinity chromatography and analyze them by nanoRP-UPLC-ESI-MS. Overall, 53 unique carbonylated peptides (37 carbonylation sites, 15 proteins) were identified. Most carbonyls were derived from dicarbonyls (mainly glyoxal). The number of carbonylation sites increased with the harsher processing from raw milk (4) to pasteurized (16) and UHT milk (16) and to IF (24). Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Electroless plating preparation and electromagnetic properties of Co-coated carbonyl iron particles/polyimide composite

    Science.gov (United States)

    Zhou, Yingying; Zhou, Wancheng; Li, Rong; Qing, Yuchang; Luo, Fa; Zhu, Dongmei

    2016-03-01

    To solve the serious electromagnetic interference problems at elevated temperature, one thin microwave-absorbing sheet employing Co-coated carbonyl iron particles and polyimide was prepared. The Co-coated carbonyl iron particles were successfully prepared using an electroless plating method. The microstructure, composition, phase and static magnetic properties of Co-coated carbonyl iron particles were characterized by combination of scanning electron microscope (SEM), energy dispersive spectrometer (EDS), X-ray diffraction (XRD) and vibrating sample magnetometer (VSM). The electromagnetic parameters of Co-coated carbonyl iron particles/polyimide composite were measured in the frequency range of 2-18 GHz, and the electromagnetic loss mechanism of the material-obtained was discussed. The microwave absorption properties of composites before and after heat treatment at 300 °C for 100 h were characterized in 2-18 GHz frequency range. It was established that composites based on Co-coated carbonyl iron demonstrate thermomagnetic stability, indicating that Co coating reduces the oxidation of carbonyl iron. Thus, Co-coated carbonyl iron particles/polyimide composites are useful in the design of microwave absorbers operating at temperatures up to 300 °C.

  15. FeCl3 -Catalyzed Ring-Closing Carbonyl-Olefin Metathesis.

    Science.gov (United States)

    Ma, Lina; Li, Wenjuan; Xi, Hui; Bai, Xiaohui; Ma, Enlu; Yan, Xiaoyu; Li, Zhiping

    2016-08-22

    Exploiting catalytic carbonyl-olefin metathesis is an ongoing challenge in organic synthesis. Reported herein is an FeCl3 -catalyzed ring-closing carbonyl-olefin metathesis. The protocol allows access to a range of carbo-/heterocyclic alkenes with good efficiency and excellent trans diastereoselectivity. The methodology presents one of the rare examples of catalytic ring-closing carbonyl-olefin metathesis. This process is proposed to take place by FeCl3 -catalyzed oxetane formation followed by retro-ring-opening to deliver metathesis products. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Engineering of a novel carbonyl reductase with coenzyme regeneration in E. coli for efficient biosynthesis of enantiopure chiral alcohols.

    Science.gov (United States)

    Wei, Ping; Gao, Jia-Xin; Zheng, Gao-Wei; Wu, Hong; Zong, Min-Hua; Lou, Wen-Yong

    2016-07-20

    The novel anti-Prelog stereospecific carbonyl reductase from Acetobacter sp. CCTCC M209061 was successfully expressed in E. coli combined with glucose dehydrogenase (GDH) to construct an efficient whole-cell biocatalyst with coenzyme NADH regeneration. The enzymatic activity of GAcCR (AcCR with a GST tag) reached 304.9U/g-dcw, even 9 folds higher than that of wild strain, and the activity of GDH for NADH regeneration recorded 46.0U/mg-protein in the recombinant E. coli. As a whole-cell biocatalyst, the recombinant E. coli BL21(DE3)pLysS (pETDuet-gaccr-gdh) possessed a broad substrate spectrum for kinds of carbonyl compounds with encouraging yield and stereoselectivity. Besides, the asymmetric reduction of ethyl 4-chloroacetoacetate (COBE) to optically pure ethyl 4-chloro-3-hydroxybutyrate (CHBE) catalyzed by the whole-cell biocatalyst was systematically investigated. Under the optimal reaction conditions, the optical purity of CHBE was over 99% e.e. for (S)-enantiomer, and the initial rate and product yield reached 8.04μmol/min and 99.4%, respectively. Moreover, the space-time yield was almost 20 folds higher than that catalyzed by the wild strain. Therefore, a new, high efficiency biocatalyst for asymmetric reductions was constructed successfully, and the enantioselective reduction of prochiral compounds using the biocatalyst was a promising approach for obtaining enantiopure chiral alcohols. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Atmospheric Sulfur Cycle Effects of Carbonyl Sulfide (OCS)

    Science.gov (United States)

    McBee, Joshua

    1996-01-01

    Carbonyl Sulfide(OCS) is considered to be one of the major sources of sulfur appearing in the stratosphere due to its relative inertness, about I to 10 yearsl. However, the roles of OCS as well as other reduced sulfur compounds such as carbon disulfide (CS2), hydrogen sulfide (H2S), and dimethyl disulfide(CH3)2S2, are not completely understood in the atmosphenc sulfur cycle. Consequently vely little information is available about the effect of sulfur compounds in the stratosphere. The ability of OCS to penetrate into the stratosphere makes it an excellent tracer for study of the role of the sulfi r cycle in stratospheric chemistry. Previously techniques such as gas chromatography and whole air sampling have been used to measure OCS analytically. Each technique had its drawbacks however, with both being quite slow, and whole air sampling being somewhat unreliable. With molecular spectroscopy, however, it has been found in recent years that the tunable diode laser absorption spectrometer (TDL) provides a very rapid and accurate method of measuring OCS and other trace gases

  18. Oxidative and reductive metabolism of lipid-peroxidation derived carbonyls.

    Science.gov (United States)

    Singh, Mahavir; Kapoor, Aniruddh; Bhatnagar, Aruni

    2015-06-05

    Extensive research has shown that increased production of reactive oxygen species (ROS) results in tissue injury under a variety of pathological conditions and chronic degenerative diseases. While ROS are highly reactive and can incite significant injury, polyunsaturated lipids in membranes and lipoproteins are their main targets. ROS-triggered lipid-peroxidation reactions generate a range of reactive carbonyl species (RCS), and these RCS spread and amplify ROS-related injury. Several RCS generated in oxidizing lipids, such as 4-hydroxy trans-2-nonenal (HNE), 4-oxo-2-(E)-nonenal (ONE), acrolein, malondialdehyde (MDA) and phospholipid aldehydes have been shown to be produced under conditions of oxidative stress and contribute to tissue injury and dysfunction by depleting glutathione and other reductants leading to the modification of proteins, lipids, and DNA. To prevent tissue injury, these RCS are metabolized by several oxidoreductases, including members of the aldo-keto reductase (AKR) superfamily, aldehyde dehydrogenases (ALDHs), and alcohol dehydrogenases (ADHs). Metabolism via these enzymes results in RCS inactivation and detoxification, although under some conditions, it can also lead to the generation of signaling molecules that trigger adaptive responses. Metabolic transformation and detoxification of RCS by oxidoreductases prevent indiscriminate ROS toxicity, while at the same time, preserving ROS signaling. A better understanding of RCS metabolism by oxidoreductases could lead to the development of novel therapeutic interventions to decrease oxidative injury in several disease states and to enhance resistance to ROS-induced toxicity. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  19. The oceanic cycle and global atmospheric budget of carbonyl sulfide

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, P.S.

    1994-12-31

    A significant portion of stratospheric air chemistry is influenced by the existence of carbonyl sulfide (COS). This ubiquitous sulfur gas represents a major source of sulfur to the stratosphere where it is converted to sulfuric acid aerosol particles. Stratospheric aerosols are climatically important because they scatter incoming solar radiation back to space and are able to increase the catalytic destruction of ozone through gas phase reactions on particle surfaces. COS is primarily formed at the surface of the earth, in both marine and terrestrial environments, and is strongly linked to natural biological processes. However, many gaps in the understanding of the global COS cycle still exist, which has led to a global atmospheric budget that is out of balance by a factor of two or more, and a lack of understanding of how human activity has affected the cycling of this gas. The goal of this study was to focus on COS in the marine environment by investigating production/destruction mechanisms and recalculating the ocean-atmosphere flux.

  20. Tropical sources and sinks of carbonyl sulfide observed from space

    Science.gov (United States)

    Glatthor, Norbert; Höpfner, Michael; Baker, Ian T.; Berry, Joe; Campbell, Elliott; Kawa, Stephan R.; Krysztofiak, Gisele; Sinnhuber, Björn-Martin; Stiller, Gabriele; Stinecipher, Jim; von Clarmann, Thomas

    2016-04-01

    According to current budget estimations the seasonal variation of carbonyl sulfide (COS) is governed by oceanic release and vegetation uptake. Its assimilation by plants is assumed to be similar to the photosynthetic uptake of CO2 but, contrary to the latter process, to be irreversible. Therefore COS has been suggested as co-tracer of the carbon cycle. Observations of COS, however, are sparse, especially in tropical regions. We use the comprehensive data set of spaceborne measurements of the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) to analyze its global distribution. Two major features are observed in the tropical upper troposphere around 250 hPa: enhanced amounts over the western Pacific and the Maritime Continent, peaking around 550 pptv in boreal summer, and a seasonally varying depletion of COS extending from tropical South America to Africa. The large-scale COS depletion, which in austral summer amounts up to -40 pptv as compared to the rest of the respective latitude band, has not been observed before and reveals the seasonality of COS uptake through tropical vegetation. The observations can only be reproduced by global models, when a large vegetation uptake and a corresponding increase in oceanic emissions as proposed in several recent publications is assumed.

  1. Photodecomposition of Molybdenum andTungsten Carbonyl Complexes

    Directory of Open Access Journals (Sweden)

    Thamer A. Alwani

    2009-01-01

    Full Text Available The photodecomposition of four different colored organometallic molybdenum and tungsten carbonyl complexes, i.e. [Mo(CO52LA] (complex I, [(Mo(CO3(bipy2LB] (complex II, [(W(CO3(tmen2LB] (complex III and [Mo(CO2LC]2 (complex I V where LA 2-phenyl-1,3-indandionebis(2-methyl anilines, LB 2-phenyl-1,3-indandione bis (4-hydroxy anilines and LCbis (2-hydroxo-benzalydine benzidine ion have been performed at 365 nm in chloroform at 25 °C under oxygen atmosphere. The absorbance spectrum of these complexes has been recorded with the time of irradiation in order to examine the kinetics of photodecomposition. The rate of the photodecomposition process was investigated and the relative values of the rate constants of dissociation (Kd for the first-order reaction are tabulated. The apparent rate constant of photodecomposition was found to be (8.33-11.50 × 10-5 s-1.

  2. Carbonyl Sulfide for Tracing Carbon Fluxes Field Campaign Report

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, J. Elliott [Univ. of California, Merced, CA (United States); Berry, Joseph A. [Carnegie Inst. of Science, Stanford, CA (United States); Billesbach, Dave [Univ. of Nebraska, Lincoln, NE (United States); Torn, Margaret S [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Zahniser, Mark [Aerodyne Research, Inc., Billerica, MA (United States); Seibt, Ulrike [Univ. of California, Los Angeles, CA (United States); Maseyk, Kadmiel [Pierre and Marie Curie Univ., Paris (France)

    2016-04-01

    The April-June 2012 campaign was located at the U.S. Department of Energy (DOE)’s Atmospheric Radiation Measurement (ARM) Climate Research Facility Southern Great Plains (SGP) site Central Facility and had three purposes. One goal was to demonstrate the ability of current instrumentation to correctly measure fluxes of atmospheric carbonyl sulfide (COS). The approach has been describe previously as a critical approach to advancing carbon cycle science1,2, but requires further investigation at the canopy scale to resolve ecosystem processes. Previous canopy-scale efforts were limited to data rates of 1Hz. While 1 Hz measurements may work in a few ecosystems, it is widely accepted that data rates of 10 to 20 Hz are needed to fully capture the exchange of traces gases between the atmosphere and vegetative canopy. A second goal of this campaign was to determine if canopy observations could provide information to help interpret the seasonal double peak in airborne observations at SGP of CO2 and COS mixing ratios. A third goal was to detect potential sources and sinks of COS that must be resolved before using COS as a tracer of gross primary productivity (GPP).

  3. Thermal characterization of magnetically aligned carbonyl iron/agar composites.

    Science.gov (United States)

    Diaz-Bleis, D; Vales-Pinzón, C; Freile-Pelegrín, Y; Alvarado-Gil, J J

    2014-01-01

    Composites of magnetic particles into polymeric matrices have received increasing research interest due to their capacity to respond to external magnetic or electromagnetic fields. In this study, agar from Gelidium robustum has been chosen as natural biocompatible polymer to build the matrix of the magnetic carbonyl iron particles (CIP) for their uses in biomedical fields. Heat transfer behavior of the CIP-agar composites containing different concentrations (5, 10, 15, 20, 25 and 30% w/w) of magnetically aligned and non-aligned CIP in the agar matrix was studied using photothermal radiometry (PTR) in the back-propagation emission configuration. The morphology of the CIP-agar composites with aligned and non-aligned CIP under magnetic field was also evaluated by scanning electron microscopy (SEM). The results revealed a dominant effect of CIP concentration over the alignment patterns induced by the magnetic field, which agrees with the behavior of the thermal diffusivity and thermal conductivity. Agar served as a perfect matrix to be used with CIP, and CIP-agar composites magnetically aligned at 20% CIP concentration can be considered as promising 'smart' material for hyperthermia treatments in the biomedical field. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Efficient and selective α-bromination of carbonyl compounds with N-bromosuccinimide under microwave

    KAUST Repository

    Guan, Xiao-Yu

    2014-02-07

    A highly efficient method for the synthesis of α-halocarbonyl compounds has been achieved via selective monobromination of aromatic and aliphatic carbonyl compounds with N-bromosuccinimide catalyzed by p-toluenesulfonic acid under microwave irradiation within 30 min.

  5. Comparison of sampling methods for radiocarbon dating of carbonyls in air samples via accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Schindler, Matthias, E-mail: matthias.schindler@physik.uni-erlangen.de; Kretschmer, Wolfgang; Scharf, Andreas; Tschekalinskij, Alexander

    2016-05-15

    Three new methods to sample and prepare various carbonyl compounds for radiocarbon measurements were developed and tested. Two of these procedures utilized the Strecker synthetic method to form amino acids from carbonyl compounds with either sodium cyanide or trimethylsilyl cyanide. The third procedure used semicarbazide to form crystalline carbazones with the carbonyl compounds. The resulting amino acids and semicarbazones were then separated and purified using thin layer chromatography. The separated compounds were then combusted to CO{sub 2} and reduced to graphite to determine {sup 14}C content by accelerator mass spectrometry (AMS). All of these methods were also compared with the standard carbonyl compound sampling method wherein a compound is derivatized with 2,4-dinitrophenylhydrazine and then separated by high-performance liquid chromatography (HPLC).

  6. Two-dimensional gel electrophoretic detection of protein carbonyls derivatized with biotin-hydrazide.

    Science.gov (United States)

    Wu, Jinzi; Luo, Xiaoting; Jing, Siqun; Yan, Liang-Jun

    2016-04-15

    Protein carbonyls are protein oxidation products that are often used to measure the magnitude of protein oxidative damage induced by reactive oxygen or reactive nitrogen species. Protein carbonyls have been found to be elevated during aging and in age-related diseases such as stroke, diabetes, and neurodegenerative diseases. In the present article, we provide detailed protocols for detection of mitochondrial protein carbonyls labeled with biotin-hydrazide followed by 2-dimensional isoelectric focusing (IEF)/SDS-PAGE and Western blotting probed with horse-radish peroxidase-conjugated streptavidin. The presented procedures can also be modified for detection of carbonylation of non-mitochondrial proteins. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Sulfenamide catalyzed oxidation of alcohols to the corresponding carbonyl compounds with anhydrous chloramine-T.

    Science.gov (United States)

    Kitagawa, Hideo; Mukaiyama, Teruaki

    2002-09-01

    N-tert-Butylbenzenesulfenamide (1) catalyzed oxidation of various alcohols with stoichiometric amount of anhydrous chloramines-T (2) proceeded smoothly at room temperature to afford the corresponding carbonyl compounds in good yields.

  8. Dipolar cycloaddition of rhodium-generated carbonyl ylides with p-quinones.

    Science.gov (United States)

    Pirrung, M C; Kaliappan, K P

    2000-02-10

    [reaction: see text] The dipolar cycloaddition of carbonyl ylides generated by the rhodium-catalyzed decomposition of delta- and epsilon-carbonyl-alpha-diazoketones with p-quinones leads to both C=O and C=C addition products. The product ratio is solvent- and catalyst-dependent and has been optimized to favor formation of either product. The C=C addition products of naphthoquinones are used in the assembly of structures hybridizing the illudin and anthraquinone anticancer agents.

  9. Protein Carbonylation and Aggregation Precede Neuronal Apoptosis Induced by Partial Glutathione Depletion

    Directory of Open Access Journals (Sweden)

    Anushka Dasgupta

    2012-02-01

    Full Text Available While the build-up of oxidized proteins within cells is believed to be toxic, there is currently no evidence linking protein carbonylation and cell death. In the present study, we show that incubation of nPC12 (neuron-like PC12 cells with 50 μM DEM (diethyl maleate leads to a partial and transient depletion of glutathione (GSH. Concomitant with GSH disappearance there is increased accumulation of PCOs (protein carbonyls and cell death (both by necrosis and apoptosis. Immunocytochemical studies also revealed a temporal/spatial relationship between carbonylation and cellular apoptosis. In addition, the extent of all three, PCO accumulation, protein aggregation and cell death, augments if oxidized proteins are not removed by proteasomal degradation. Furthermore, the effectiveness of the carbonyl scavengers hydralazine, histidine hydrazide and methoxylamine at preventing cell death identifies PCOs as the toxic species. Experiments using well-characterized apoptosis inhibitors place protein carbonylation downstream of the mitochondrial transition pore opening and upstream of caspase activation. While the study focused mostly on nPC12 cells, experiments in primary neuronal cultures yielded the same results. The findings are also not restricted to DEM-induced cell death, since a similar relationship between carbonylation and apoptosis was found in staurosporine- and buthionine sulfoximine-treated nPC12 cells. In sum, the above results show for the first time a causal relationship between carbonylation, protein aggregation and apoptosis of neurons undergoing oxidative damage. To the best of our knowledge, this is the first study to place direct (oxidative protein carbonylation within the apoptotic pathway.

  10. Chemoselective Reduction and Alkylation of Carbonyl Functions Using Phosphonium Salts as an in Situ Protecting Groups.

    Science.gov (United States)

    Ohta, Reiya; Fujioka, Hiromichi

    2017-01-01

    Recent progress in the chemoselective reduction and alkylation of carbonyl functions using our in situ protection method is described. Methods that enable reversal or control of the reactivity of a carbonyl functional group are potentially useful. They open up new areas of synthetic organic chemistry and change the concept of retrosynthesis because they remove the need for complicated protection/deprotection sequences. In this account, we discuss the strategy and applications of our in situ protection method using phosphonium salts.

  11. Functionalization of 6-Nitrobenzo[1,3]dioxole with Carbonyl Compounds via TDAE methodology

    Directory of Open Access Journals (Sweden)

    Patrice Vanelle

    2005-05-01

    Full Text Available We report herein the synthesis of substituted 2-(6-nitrobenzo[1,3]dioxol-5-yl-1- aryl ethanols and 2-(6-nitrobenzo[1,3]dioxol-5-yl-propionic acid ethyl esters from the reaction of 5-chloromethyl-6-nitrobenzo[1,3]dioxole with various aromatic carbonyl and α- carbonyl ester derivatives using the tetrakis(dimethylaminoethylene (TDAE methodology.

  12. Ketene as a Reaction Intermediate in the Carbonylation of Dimethyl Ether to Methyl Acetate over Mordenite.

    Science.gov (United States)

    Rasmussen, Dominik B; Christensen, Jakob M; Temel, Burcin; Studt, Felix; Moses, Poul Georg; Rossmeisl, Jan; Riisager, Anders; Jensen, Anker D

    2015-06-15

    Unprecedented insight into the carbonylation of dimethyl ether over Mordenite is provided through the identification of ketene (CH2CO) as a reaction intermediate. The formation of ketene is predicted by detailed DFT calculations and verified experimentally by the observation of doubly deuterated acetic acid (CH2DCOOD), when D2O is introduced in the feed during the carbonylation reaction. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Selective Palladium(II)-Catalyzed Carbonylation of Methylene β-C-H Bonds in Aliphatic Amines.

    Science.gov (United States)

    Cabrera-Pardo, Jaime R; Trowbridge, Aaron; Nappi, Manuel; Ozaki, Kyohei; Gaunt, Matthew J

    2017-09-18

    Palladium(II)-catalyzed C-H carbonylation reactions of methylene C-H bonds in secondary aliphatic amines lead to the formation of trans-disubstituted β-lactams in excellent yields and selectivities. The generality of the C-H carbonylation process is aided by the action of xantphos-based ligands and is important in securing good yields for the β-lactam products. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Oxidative Stress and Carbonyl Lesions in Ulcerative Colitis and Associated Colorectal Cancer

    Directory of Open Access Journals (Sweden)

    Zhiqi Wang

    2016-01-01

    Full Text Available Oxidative stress has long been known as a pathogenic factor of ulcerative colitis (UC and colitis-associated colorectal cancer (CAC, but the effects of secondary carbonyl lesions receive less emphasis. In inflammatory conditions, reactive oxygen species (ROS, such as superoxide anion free radical (O2∙-, hydrogen peroxide (H2O2, and hydroxyl radical (HO∙, are produced at high levels and accumulated to cause oxidative stress (OS. In oxidative status, accumulated ROS can cause protein dysfunction and DNA damage, leading to gene mutations and cell death. Accumulated ROS could also act as chemical messengers to activate signaling pathways, such as NF-κB and p38 MAPK, to affect cell proliferation, differentiation, and apoptosis. More importantly, electrophilic carbonyl compounds produced by lipid peroxidation may function as secondary pathogenic factors, causing further protein and membrane lesions. This may in turn exaggerate oxidative stress, forming a vicious cycle. Electrophilic carbonyls could also cause DNA mutations and breaks, driving malignant progression of UC. The secondary lesions caused by carbonyl compounds may be exceptionally important in the case of host carbonyl defensive system deficit, such as aldo-keto reductase 1B10 deficiency. This review article updates the current understanding of oxidative stress and carbonyl lesions in the development and progression of UC and CAC.

  15. COMPARATIVE STUDY OF EFFICACY OF FERROUS SULPHATE AND CARBONYL IRON IN ANEMIA OF ANTENATAL WOMEN

    Directory of Open Access Journals (Sweden)

    Radhika

    2015-03-01

    Full Text Available Iron deficiency anemia is the most common and important public health problem all over the world in the risk group of antenatal women. Research is going on to improve the iron status of the pregnant women with different forms of iron available. In this regard, Carbonyl Iron is showing promising results in improving the red cell mass with better compliance. 120 antenatal women were recruited in this study. The study comprised of 6weeks for each patient. They were given Carbonyl Iron 100 mg/day and FeS04 100gm/day . Before and after treatment all the baseline and specific investigations were one. Results were tabulated, comparison and significance were tested by unpaired student ’s’ test and their 'p' value was calculated. Results were shown graphically also. Carbonyl Iron showed improvement in hemoglobin, PCV and better than ferrous Sulphate (P <0.001. Incidence of side effects were less with Carbonyl Iron than Ferrous Sulphate, better compliance was seen with Carbonyl Iron. In conclusion, the present study s howed that Carbonyl Iron had better efficacy and safety in the management of Iron deficiency anemia in antenatal women than ferrous Sulphate

  16. Brand variation in oxidant production in mainstream cigarette smoke: Carbonyls and free radicals.

    Science.gov (United States)

    Reilly, Samantha M; Goel, Reema; Trushin, Neil; Elias, Ryan J; Foulds, Jonathan; Muscat, Joshua; Liao, Jason; Richie, John P

    2017-08-01

    Oxidative stress/damage resulting from exposure to cigarette smoke plays a critical role in the development of tobacco-caused diseases. Carbonyls and free radicals are two major classes of oxidants in tobacco smoke. There is little information on the combined delivery of these oxidants across different cigarette brands; thus, we set out to measure and compare their levels in mainstream smoke from popular US cigarettes. Mainstream smoke from 28 different cigarette brands produced by smoking (FTC protocol) was analyzed for five important, abundant carbonyls, and levels were compared to previously determined free radical for the same brands. Overall, there were large variations (3- to 6-fold) in carbonyl levels across brands with total carbonyl levels ranging from 275 to 804 μg/cigarette, which persisted even after adjusting for ventilation. Individual carbonyl levels were highly correlated with each other (r2: 0.40-0.95, P < 0.003) except for formaldehyde. Both gas-phase (r2: 0.37, P = 0.006) and particulate-phase (r2: 0.27, P = 0.005) free radicals were correlated to total carbonyl content; however, this correlation disappeared after adjusting for ventilation. These data show that overall oxidant production varies widely by cigarette brand and the resulting difference in oxidant burden could potentially lead to differences in disease risk. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. New Ir Bis-Carbonyl Precursor for Water Oxidation Catalysis

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Daria L. [Department of Chemistry, Yale University, 225; Beltrán-Suito, Rodrigo [Department of Chemistry, Yale University, 225; Thomsen, Julianne M. [Department of Chemistry, Yale University, 225; Hashmi, Sara M. [Department of Chemical and Environmental; Materna, Kelly L. [Department of Chemistry, Yale University, 225; Sheehan, Stafford W. [Catalytic Innovations LLC, 70 Crandall; Mercado, Brandon Q. [Department of Chemistry, Yale University, 225; Brudvig, Gary W. [Department of Chemistry, Yale University, 225; Crabtree, Robert H. [Department of Chemistry, Yale University, 225

    2016-02-05

    This paper introduces IrI(CO)2(pyalc) (pyalc = (2-pyridyl)-2-propanoate) as an atom-efficient precursor for Ir-based homogeneous oxidation catalysis. This compound was chosen to simplify analysis of the water oxidation catalyst species formed by the previously reported Cp*IrIII(pyalc)OH water oxidation precatalyst. Here, we present a comparative study on the chemical and catalytic properties of these two precursors. Previous studies show that oxidative activation of Cp*Ir-based precursors with NaIO4 results in formation of a blue IrIV species. This activation is concomitant with the loss of the placeholder Cp* ligand which oxidatively degrades to form acetic acid, iodate, and other obligatory byproducts. The activation process requires substantial amounts of primary oxidant, and the degradation products complicate analysis of the resulting IrIV species. The species formed from oxidation of the Ir(CO)2(pyalc) precursor, on the other hand, lacks these degradation products (the CO ligands are easily lost upon oxidation) which allows for more detailed examination of the resulting Ir(pyalc) active species both catalytically and spectroscopically, although complete structural analysis is still elusive. Once Ir(CO)2(pyalc) is activated, the system requires acetic acid or acetate to prevent the formation of nanoparticles. Investigation of the activated bis-carbonyl complex also suggests several Ir(pyalc) isomers may exist in solution. By 1H NMR, activated Ir(CO)2(pyalc) has fewer isomers than activated Cp*Ir complexes, allowing for advanced characterization. Future research in this direction is expected to contribute to a better structural understanding of the active species. A diol crystallization agent was needed for the structure determination of 3.

  18. Binding of ether and carbonyl oxygens to lithium ion

    Energy Technology Data Exchange (ETDEWEB)

    Blint, R.J. [Physical Chemistry Dept., Warren, MI (United States)

    1994-12-31

    The electrolyte for a lithium battery is a lithium salt (e.g. lithium Perchlorate) dissolved in an organic solvent or a mixture of organic solvents. The conductivity in these electrolytes is ionic and needs to be as high as possible to efficiently remove energy from the battery. The diffusion coefficient of the solvated ion in liquid electrolytes is inversely dependent on the radius of the salvation sphere. Consequently conductivity will increase with a decrease in the size of the salvation shell. The size of the salvation shell is determined by the size and coordination number of the solvent molecules. The types of organic solvents in electrolytes used in lithium battery applications are usually differentiated based on their perceived solvation properties. These solvents are often small, oxygen containing organic molecules which move with the Li{sup +} ions. This paper calculates the binding energies of some of these solvents to Li{sup +} using molecular quantum mechanics (MQM) techniques. The binding energies of the various solvents to Li{sup +} may determine which solvents will be preferentially bound to the ion. In liquid organic electrolytes, then, it will be the identity of the solvent and the coordination number which most affect the conductivity; the binding energies determine both of these properties. Carbonyl oxygens which occur in formaldehyde, acetaldehyde, acetone, ethylene carbonate and propylene carbonate have different Li{sup +} bonding properties than do the ether oxygens which occur in water, dimethyl ether and diethyl ether. Polymer solvents for the lithium salts such as the polyethers have chains which are too long to move with the binding energies then serve as the basis for a different Li{sup +} transport. Dimethyl ether and diethyl ether serve both as solvents and models for the polyethers.

  19. Plasma protein carbonyl responses to anaerobic exercise in female cyclists

    Directory of Open Access Journals (Sweden)

    M.E Afzalpour

    2016-03-01

    Full Text Available Single bouts of aerobic exercise may leads to oxidative stress due to the use of oxygen for metabolism and the generation of reactive oxygen. In athletes, oxidative stress can lead to several deleterious performance effects, such as muscular oxidative damage, muscle soreness, loss of skeletal muscle force production and/or inflammation. However, little is known regarding the severity and duration of oxidative stress arising from intensive anaerobic modes of exercise in aerobically-trained athletes. The purpose of this study was to investigate the effect of a single bout of intensive anaerobic exercise on plasma protein carbonyl (PC in aerobically-trained women. Aerobically-trained, provincial female cyclists [n = 18, age: 24.2±2.7 years; stature: 163.6±4.6 cm; body mass: 53.4±4.2 kg] were randomly assigned into either a non-exercising control (CON; n = 9 or experimental (EXP; n = 9 group that underwent a 30-second anaerobic (Wingate cycle ergometer exercise session. Blood sampling took place before exercise, immediately after the exercise (IE, and 24 hours following the exercise (24HR bout. In the EXP, results indicated significant (P ≤ 0.05 differences in PC levels between the pre-test and IE (0.010±0.0124 to 0.0149±0.0420 mmol/milt; P = 0.010, and IE and 24HR (0.0149±0.0420 to 0.0111±0.0183 mmol/milt; P = 0.013. No significant differences were observed between pre-test and 24HR (0.010±0.0124 to 0.0111±0.0183 mmol/milt; P = 0.371. These results indicate that oxidative protein damage, as indicated by PC levels, rises immediately with the onset of anaerobic exercise, but returns to resting levels within 24 hours following exercise in aerobically-trained women.

  20. Reactive Carbonyl Species Mediate ABA Signaling in Guard Cells.

    Science.gov (United States)

    Islam, Md Moshiul; Ye, Wenxiu; Matsushima, Daiki; Munemasa, Shintaro; Okuma, Eiji; Nakamura, Yoshimasa; Biswas, Sanaullah; Mano, Jun'ichi; Murata, Yoshiyuki

    2016-12-01

    Drought is responsible for a massive reduction in crop yields. In response to drought, plants synthesize the hormone ABA, which induces stomatal closure, thus reducing water loss. In guard cells, ABA triggers production of reactive oxygen species (ROS), which is mediated by NAD(P)H oxidases. The production of ROS is a key factor for ABA-induced stomatal closure, but it remains to be clarified how the production of ROS is transduced into downstream signaling components in guard cells. We investigated roles of reactive carbonyl species (RCS) in ABA-induced stomatal closure using transgenic tobacco (Nicotiana tabacum) overexpressing Arabidopsis 2-alkenal reductase (AER-OE), which scavenges RCS. ABA and hydrogen peroxide (H2O2) induced accumulation of RCS including acrolein and 4-hydroxy-(E)-2-nonenal in wild-type tobacco but not in AER-OE. Stomatal closure and RCS accumulation in response to ABA and H2O2 were inhibited in AER-OE unlike in the wild type, while ABA-induced H2O2 production in guard cells was observed in AER-OE as well as in the wild type. Moreover, ABA inhibited inward-rectifying K(+) channels in wild-type guard cells but not in AER-OE guard cells. These results suggest that RCS is involved in ABA-induced stomatal closure and functions downstream of H2O2 production in the ABA signaling pathway in guard cells. © The Authors 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  1. Intramolecular Hydrogen Bond in Biologically Active o-Carbonyl Hydroquinones

    Directory of Open Access Journals (Sweden)

    Maximiliano Martínez-Cifuentes

    2014-07-01

    Full Text Available Intramolecular hydrogen bonds (IHBs play a central role in the molecular structure, chemical reactivity and interactions of biologically active molecules. Here, we study the IHBs of seven related o-carbonyl hydroquinones and one structurally-related aromatic lactone, some of which have shown anticancer and antioxidant activity. Experimental NMR data were correlated with theoretical calculations at the DFT and ab initio levels. Natural bond orbital (NBO and molecular electrostatic potential (MEP calculations were used to study the electronic characteristics of these IHB. As expected, our results show that NBO calculations are better than MEP to describe the strength of the IHBs. NBO energies (∆Eij(2 show that the main contributions to energy stabilization correspond to LPàσ* interactions for IHBs, O1…O2-H2 and the delocalization LPàπ* for O2-C2 = Cα(β. For the O1…O2-H2 interaction, the values of ∆Eij(2 can be attributed to the difference in the overlap ability between orbitals i and j (Fij, instead of the energy difference between them. The large energy for the LP O2àπ* C2 = Cα(β interaction in the compounds 9-Hydroxy-5-oxo-4,8, 8-trimethyl-l,9(8H-anthracenecarbolactone (VIII and 9,10-dihydroxy-4,4-dimethylanthracen-1(4H-one (VII (55.49 and 60.70 kcal/mol, respectively when compared with the remaining molecules (all less than 50 kcal/mol, suggests that the IHBs in VIII and VII are strongly resonance assisted.

  2. Nicotine, aerosol particles, carbonyls and volatile organic compounds in tobacco- and menthol-flavored e-cigarettes.

    Science.gov (United States)

    Lee, Mi-Sun; LeBouf, Ryan F; Son, Youn-Suk; Koutrakis, Petros; Christiani, David C

    2017-04-27

    We aimed to assess the content of electronic cigarette (EC) emissions for five groups of potentially toxic compounds that are known to be present in tobacco smoke: nicotine, particles, carbonyls, volatile organic compounds (VOCs), and trace elements by flavor and puffing time. We used ECs containing a common nicotine strength (1.8%) and the most popular flavors, tobacco and menthol. An automatic multiple smoking machine was used to generate EC aerosols under controlled conditions. Using a dilution chamber, we targeted nicotine concentrations similar to that of exposure in a general indoor environment. The selected toxic compounds were extracted from EC aerosols into a solid or liquid phase and analyzed with chromatographic and spectroscopic methods. We found that EC aerosols contained toxic compounds including nicotine, fine and nanoparticles, carbonyls, and some toxic VOCs such as benzene and toluene. Higher mass and number concentrations of aerosol particles were generated from tobacco-flavored ECs than from menthol-flavored ECs. We found that diluted machine-generated EC aerosols contain some pollutants. These findings are limited by the small number of ECs tested and the conditions of testing. More comprehensive research on EC exposure extending to more brands and flavor compounds is warranted.

  3. Organometallic and Bioorganometallic Chemistry - Ferrocene and Metal Carbonyls

    Directory of Open Access Journals (Sweden)

    Čakić Semenčić, M.

    2011-02-01

    Full Text Available Organometallic chemistry deals with compounds containing metal-carbon bonds. Basic organometallics derived from the s- and p-block metals (containing solely σ-bonds were understood earlier, while organometallic chemistry of the d- and f-block has developed much more recently. These compounds are characterized by three types of M-C bonds (σ, π and δand their structures are impossible to deduce by chemical means alone; fundamental advances had to await the development of X-ray diffraction, as well as IR- and NMR-spectroscopy. On the other hand, elucidation of the structure of e. g. vitamin B12 and ferrocene (discovered in 1951 contributed to progress in these instrumental analytical methods, influencing further phenomenal success of transition-metal organometallic chemistry in the second half of the twentieth century. The most thoroughly explored fields of application of organometallics were in the area of catalysis, asymmetric synthesis, olefin metathesis, as well as organic synthesis and access to new materials and polymers.The most usual ligands bound to d- and f-metals are carbon monoxide, phosphines, alkyls, carbenes and arenes, and in this review the bonding patterns in the metal carbonyls and ferrocene are elaborated. The common characteristics of these two classes are two-component bonds. The CO-M bonds include (i donation from ligand HOMO to vacant M d-orbitals (σ-bond, and (ii back-donation from the filled M d-orbitals in the ligand LUMO (π-bond. Similar (but much more complicated ferrocene contains delocalized bonds consisting of electron donation from Cp to Fe (σ-bonds- and π-bonding and δ-back-bonding from metal to Cp. In such a way ferrocene, i. e. (η5-Cp2Fe contains 18 bonding electrons giving to this compound "superaromatic" properties in the sense of stability and electrophilic substitution. In contrast to benzenoid aromatic compounds reactions in two Cp-rings can occur giving homo- and heteroannularly mono-, two-… per

  4. Excited state evolution towards ligand loss and ligand chelation at group 6 metal carbonyl centres.

    Science.gov (United States)

    Manton, Jennifer C; Amirjalayer, Saeed; Coleman, Anthony C; McMahon, Suzanne; Harvey, Emma C; Greetham, Gregory M; Clark, Ian P; Buma, Wybren Jan; Woutersen, Sander; Pryce, Mary T; Long, Conor

    2014-12-21

    The photochemistry and photophysics of three model "half-sandwich" complexes (η(6)-benzophenone)Cr(CO)3, (η(6)-styrene)Cr(CO)3, and (η(6)-allylbenzene)Cr(CO)3 were investigated using pico-second time-resolved infrared spectroscopy and time-dependent density functional theory methods. The (η(6)-benzophenone)Cr(CO)3 complex was studied using two excitation wavelengths (470 and 320 nm) while the remaining complexes were irradiated using 400 nm light. Two independent excited states were detected spectroscopically for each complex, one an unreactive excited state of metal-to-arene charge-transfer character and the other with metal-to-carbonyl charge transfer character. This second excited state leads to an arrested release of CO on the pico-second time-scale. Low-energy excitation (470 nm) of (η(6)-benzophenone)Cr(CO)3 populated only the unreactive excited state which simply relaxes to the parent complex. Higher energy irradiation (320 nm) induced CO-loss. Irradiation of (η(6)-styrene)Cr(CO)3, or (η(6)-allylbenzene)Cr(CO)3 at 400 nm provided evidence for the simultaneous population of both the reactive and unreactive excited states. The efficiency at which the unreactive excited state is populated depends on the degree of conjugation of the substituent with the arene π-system and this affects the efficiency of the CO-loss process. The quantum yield of CO-loss is 0.50 for (η(6)-allylbenzene)Cr(CO)3 and 0.43 for (η(6)-styrene)Cr(CO)3. These studies provide evidence for the existence of two photophysical routes to CO loss, a minor ultrafast route and an arrested mechanism involving the intermediate population of a reactive excited state. This reactive excited state either relaxes to reform the parent species or eject CO. Thus the quantum yield of the CO-loss is strongly dependent on the excitation wavelength. Time-dependent density functional theory calculations confirm that the state responsible for ultrafast CO-loss has significant metal-centred character while

  5. Comparison of extraction techniques and mass spectrometric ionization modes in the analysis of wine volatile carbonyls

    Energy Technology Data Exchange (ETDEWEB)

    Zapata, Julian; Mateo-Vivaracho, Laura; Cacho, Juan [Laboratory for Flavor Analysis and Enology, Institute of Engineering of Aragon, I3A, Department of Analytical Chemistry, Faculty of Sciences, University of Zaragoza, 50009 Zaragoza (Spain); Ferreira, Vicente, E-mail: vferre@unizar.es [Laboratory for Flavor Analysis and Enology, Institute of Engineering of Aragon, I3A, Department of Analytical Chemistry, Faculty of Sciences, University of Zaragoza, 50009 Zaragoza (Spain)

    2010-02-15

    This work presents a comparative study of the analytical characteristics of two methods for the analysis of carbonyl compounds in wine, both based on the derivatization with O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine hydrochloride (PFBHA). In the first method derivatives are formed in the solid phase extraction (SPE) cartridge in which the analytes have been previously isolated, while in the second method derivatives are formed in a solid phase microextraction (SPME) fibre saturated with vapors of the reagent and exposed to the sample headspace. In both cases detection has been carried out by electron impact (EI) or negative chemical ionization (NCI) mass spectrometry. The possibility of determining haloanisols simultaneously has been also considered. The method based on SPE presents, in general, better analytical properties than the SPME one. Although linearity was satisfactory for both methods (R{sup 2} > 0.99), repeatability of the SPE method (RSD < 10%) was better than that obtained with SPME (9% < RSD < 20%). Detection limits obtained with EI are better for the SPE method except for trihaloanisols, while with NCI detection limits for both strategies are comparable, although the SPME strategy presents worse results for ketones and methional. Detection limits are always lower with NCI, being the improvement most notable for SPME. Recovery experiments show that in the case of SPE, uncertainties are lower than 12% in all cases, while with the SPME method the imprecision plus the existence of matrix effects make the global uncertainty to be higher than 15%.

  6. Microwave absorbing property of a hybrid absorbent with carbonyl irons coating on the graphite

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Yonggang, E-mail: xuyonggang221@163.com [Science and Technology on Electromagnetic Scattering Laboratory, Shanghai, 200438 (China); Yan, Zhenqiang; Zhang, Deyuan [Bionic and Micro/Nano/Bio Manufacturing Technology Research Center, School of Mechanical Engineering and Automation, Beihang University, Beijing 100191 (China)

    2015-11-30

    Graphical abstract: The absorbing property could be enhanced as the CIPs coated on the graphite. - Highlights: • Absorbers filled with CIPs coating on the graphite was fabricated. • The permittivity and permeability increased as CIPs coated. • The CIP materials enhanced the electromagnetic property. • The graphite coated CIPs were effective in 2–18 GHz. - Abstract: The hybrid absorbent filled with carbonyl iron particles (CIPs) coating on the graphite was prepared using a chemical vapor decomposition (CVD) process. X-ray diffraction (XRD) patterns were done to analyze the particle crystal grain structure. The complex permittivity and permeability were measured using a vector network analyzer in the frequency range of 2–18 GHz. The results showed that α-Fe appeared in the super-lattice diffraction peaks in XRD graph. The composites added CIPs coating on the graphite had a higher permittivity and imaginary permeability due to the superior microwave dielectric loss and magnetic loss of the CIPs. The reflection loss (RL) result showed that composites filled with 5 vol% Fe-graphite had an excellent absorbing property in the 2–18 GHz, the minimum RL was −25.14 dB at 6 mm and −26.52 dB at 8 mm, respectively.

  7. Carbonyl sulfide removal with compost and wood chip biofilters, and in the presence of hydrogen sulfide.

    Science.gov (United States)

    Sattler, Melanie L; Garrepalli, Divya R; Nawal, Chandraprakash S

    2009-12-01

    Carbonyl sulfide (COS) is an odor-causing compound and hazardous air pollutant emitted frequently from wastewater treatment facilities and chemical and primary metals industries. This study examined the effectiveness of biofiltration in removing COS. Specific objectives were to compare COS removal efficiency for various biofilter media; to determine whether hydrogen sulfide (H2S), which is frequently produced along with COS under anaerobic conditions, adversely impacts COS removal; and to determine the maximum elimination capacity of COS for use in biofilter design. Three laboratory-scale polyvinyl chloride biofilter columns were filled with up to 28 in. of biofilter media (aged compost, fresh compost, wood chips, or a compost/wood chip mixture). Inlet COS ranged from 5 to 46 parts per million (ppm) (0.10-9.0 g/m3 hr). Compost and the compost/wood chip mixture produced higher COS removal efficiencies than wood chips alone. The compost and compost/wood chip mixture had a shorter stabilization times compared with wood chips alone. Fresh versus aged compost did not impact COS removal efficiency. The presence of H2S did not adversely impact COS removal for the concentration ratios tested. The maximum elimination capacity is at least 9 g/m3 hr for COS with compost media.

  8. Improvement of operational stability of Ogataea minuta carbonyl reductase for chiral alcohol production.

    Science.gov (United States)

    Honda, Kohsuke; Inoue, Mizuha; Ono, Tomohiro; Okano, Kenji; Dekishima, Yasumasa; Kawabata, Hiroshi

    2017-06-01

    Directed evolution of enantio-selective carbonyl reductase from Ogataea minuta was conducted to improve the operational stability of the enzyme. A mutant library was constructed by an error-prone PCR and screened using a newly developed colorimetric assay. The stability of a mutant with two amino acid substitutions was significantly higher than that of the wild type at 50°C in the presence of dimethyl sulfoxide. Site-directed mutagenesis analysis showed that the improved stability of the enzyme can be attributed to the amino acid substitution of V166A. The half-lives of the V166A mutant were 11- and 6.1-times longer than those of the wild type at 50°C in the presence and absence, respectively, of 20% (v/v) dimethyl sulfoxide. No significant differences in the substrate specificity and enantio-selectivity of the enzyme were observed. The mutant enzyme converted 60 mM 2,2,2-trifluoroacetophenone to (R)-(-)-α-(trifluoromethyl)benzyl alcohol in a molar yield of 71% whereas the conversion yield with an equivalent concentration of the wild-type enzyme was 27%. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  9. Benchmarking of protein carbonylation analysis in Caenorhabditis elegans: specific considerations and general advice.

    Science.gov (United States)

    Pyr Dit Ruys, S; Bonzom, J-M; Frelon, S

    2016-10-01

    Oxidative stress has been extensively studied due to its correlation with cellular disorders and aging. In proteins, one biomarker of oxidative stress is the presence of carbonyl groups, such as aldehyde and ketone, in specific amino acid side chains such as lysine, proline, arginine and threonine, so-called protein carbonylation (PC). PC study is now a growing field in general and medical science since PC accumulation is associated with various pathologies and disorders. At present, enzyme-linked immunosorbent assays (ELISA) seem to be the most robust method of quantifying the presence of carbonyl groups in proteins, despite having some recognised caveats. In parallel, gel-based approaches present cross-comparison difficulties, along with other technical problems. As generic PC analyses still suffer from poor homogeneity, leading to cross-data analysis difficulties and poor results overlap, the need for harmonisation in the field of carbonyl detection is now widely accepted. This study aims to highlight some of the technical challenges in proteomic gel-based multiplexing experiments when dealing with PC in difficult samples like those from Caenorhabditis elegans, from protein extraction to carbonyl detection. We demonstrate that some critical technical parameters, such as labelling time, probe concentration, and total and carbonylated protein recovery rates, should be re-addressed in a sample-specific way. We also defined a procedure to cost-effectively adapt CyDye™-hydrazide-based protocols to specific samples, especially when the experimental interest is focused on studying differences between stimulating conditions with a maximised signal-to-noise ratio. Moreover, we have improved an already-existing powerful solubilisation buffer, making it potentially useful for hard-to-solubilise protein pellets. Lastly, the depicted methodology exemplifies a simple way of normalising carbonyl-related signal to total protein in SDS-PAGE multiplexing experiments. Within

  10. Proteomic identification of carbonylated proteins in F344 rat hippocampus after 1-bromopropane exposure

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Zhenlie [Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, Nagoya 466‐8550 (Japan); Department of Toxicology, Guangdong Prevention and Treatment Center for Occupational Diseases, Guangzhou 510‐300 (China); Ichihara, Sahoko [Graduate School of Regional Innovation Studies, Mie University, Tsu 514‐8507 (Japan); Oikawa, Shinji [Department of Environmental and Molecular Medicine, Mie University Graduate School of Medicine, Mie 514‐8507 (Japan); Chang, Jie; Zhang, Lingyi; Subramanian, Kaviarasan; Mohideen, Sahabudeen Sheik [Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, Nagoya 466‐8550 (Japan); Ichihara, Gaku, E-mail: gak@med.nagoya-u.ac.jp [Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, Nagoya 466‐8550 (Japan)

    2012-08-15

    1-Bromopropane (1-BP) is neurotoxic in both experimental animals and humans. Previous proteomic analysis of rat hippocampus implicated alteration of protein expression in oxidative stress, suggesting that oxidative stress plays a role in 1-BP-induced neurotoxicity. To understand this role at the protein level, we exposed male F344 rats to 1-BP at 0, 400, or 1000 ppm for 8 h/day for 1 week or 4 weeks by inhalation and quantitated changes in hippocampal protein carbonyl using a protein carbonyl assay, two-dimensional gel electrophoresis (2-DE), immunoblotting, and matrix-assisted laser-desorption ionization time-of-flight mass spectrometry (MALDI-TOF-TOF/MS). Hippocampal reactive oxygen species and protein carbonyl were significantly increased, demonstrating 1-BP-associated induction of oxidative stress and protein damage. MALDI-TOF-TOF/MS identified 10 individual proteins with increased carbonyl modification (p < 0.05; fold-change ≥ 1.5). The identified proteins were involved in diverse biological processes including glycolysis, ATP production, tyrosine catabolism, GTP binding, guanine degradation, and neuronal metabolism of dopamine. Hippocampal triosephosphate isomerase (TPI) activity was significantly reduced and negatively correlated with TPI carbonylation (p < 0.001; r = 0.83). Advanced glycation end-product (AGE) levels were significantly elevated both in the hippocampus and plasma, and hippocampal AGEs correlated negatively with TPI activity (p < 0.001; r = 0.71). In conclusion, 1-BP-induced neurotoxicity in the rat hippocampus seems to involve oxidative damage of cellular proteins, decreased TPI activity, and elevated AGEs. -- Highlights: ► 1-BP increases hippocampal ROS levels and hippocampal and plasma protein carbonyls. ► 1-BP increases TPI carbonylation and decreases TPI activity in the hippocampus. ► 1-BP increases hippocampal and plasma AGE levels.

  11. Atmospheric Levels of Benzene and C1-C2 Carbonyls in San Nicolas de los Garza, Nuevo Leon, Mexico: Source Implications and Health Risk

    Directory of Open Access Journals (Sweden)

    Julia Griselda Cerón Bretón

    2017-10-01

    Full Text Available Atmospheric benzene and carbonyls were studied in San Nicolas de los Garza, Nuevo Leon, during 2011 and 2012. The relative abundance for measured VOCs was the following: formaldehyde (9.06 µg m−3 > acetaldehyde (8.06 µg m−3 > benzene (0.65 µg m−3. All measured VOCs had a clear seasonal trend with higher values of concentration during summer. Benzene and formaldehyde had a marked diurnal trend with the highest levels during morning, whereas acetaldehyde did not show a clear diurnal pattern. Meteorological analysis showed that the dominant winds came from NNE and ENE, suggesting that sources located in these directions contribute to the VOC levels. Principal component analysis (PCA analysis revealed that photochemical activity influenced benzene and carbonyl levels during summer and that benzene was associated with vehicular traffic emissions during autumn and winter, showing good correlation with CO. Meteorological data showed that measured VOCs were influenced by regional sources. A health risk assessment showed that local exposure to carbonyls and benzene exceeded 1 × 10−6 for integrated lifetime cancer risk. People living in San Nicolas de los Garza, thus, have a probable risk of suffering cancer in their lifetime. It is, therefore, necessary to improve environmental policies for controlling VOC levels in this area.

  12. Proteomic quantification and identification of carbonylated proteins upon oxidative stress and during cellular aging.

    Science.gov (United States)

    Baraibar, Martin A; Ladouce, Romain; Friguet, Bertrand

    2013-10-30

    Increased protein carbonyl content is a hallmark of cellular and organismal aging. Protein damage leading to the formation of carbonyl groups derives from direct oxidation of several amino acid side chains but can also derive through protein adducts formation with lipid peroxidation products and dicarbonyl glycating compounds. All these modifications have been implicated during oxidative stress, aging and age-related diseases. However, in most cases, the proteins targeted by these deleterious modifications as well as their consequences have not yet been clearly identified. Indeed, this is essential to determine whether and how these modified proteins are impacting on cellular function, on the development of the senescent phenotype and the pathogenesis of age-related diseases. In this context, protein modifications occurring during aging and upon oxidative stress as well as main proteomic methods for detecting, quantifying and identifying oxidized proteins are described. Relevant proteomics studies aimed at monitoring the extent of protein carbonylation and identifying the targeted proteins in the context of aging and oxidative stress are also presented. Proteomics approaches, i.e. fluorescent based 2D-gel electrophoresis and mass spectrometry methods, represent powerful tools for monitoring at the proteome level the extent of protein oxidative and related modifications and for identifying the targeted proteins. Accumulation of damaged macromolecules, including oxidatively damaged (carbonylated) proteins, is a hallmark of cellular and organismal aging. Since protein carbonyls are the most commonly used markers of protein oxidation, different methods have been developed for the detection and quantification of carbonylated proteins. The identification of these protein targets is of valuable interest in order to understand the mechanisms by which damaged proteins accumulate and potentially affect cellular functions during oxidative stress, cellular senescence and

  13. Iron dextran treatment does not induce serum protein carbonyls in the newborn pig.

    Science.gov (United States)

    Caperna, T J; Shannon, A E; Blomberg, L A; Garrett, W M; Ramsay, T G

    2012-01-01

    Oxidation of serum proteins can lead to carbonyl formation that alters their function and is often associated with stress-related diseases. As it is recommended that all pigs reared in modern production facilities be given supplemental iron at birth to prevent anemia, and metals can catalyze the carbonylation of proteins, the primary objective of this study was to determine whether standard iron dextran treatment was associated with enhanced serum protein oxidation in newborn piglets. Piglets were treated with 100 mg of iron dextran intramuscularly either on the day of birth, or on the third day after birth. Blood samples were collected from piglets 48 or 96 h after treatment and serum was harvested. For quantification, serum protein carbonyls were converted to hydrazones with dinitrophenyl hydrazine and analyzed spectrophotometrically. To identify and determine relative distribution of carbonylated proteins, serum protein carbonyls were derivatized with biotin hydrazide, separated by two-dimensional polyacrylamide gel electrophoresis, stained with avidin-fluorescein and identified by mass spectrometry. The standard iron dextran treatment was associated with no increase in total oxidized proteins if given either on the first or third day of life. In addition, with a few noted exceptions, the overall distribution and identification of oxidized proteins were similar between control and iron dextran-treated pigs. These results indicate that while iron dextran treatment is associated with a marked increase in circulating iron, it does not appear to specifically induce the oxidation of serum proteins.

  14. [Source profile of volatile carbonyl compounds in wastewater treatment plant of an oil refinery].

    Science.gov (United States)

    Zhou, Bo-Yu; Liu, Wang; Wang, Bo-Guang; Zhou, Mi; Huang, Qing; Zhou, Lei

    2013-07-01

    An observation was conducted at the wastewater treatment plant in a refinery in Guangdong province, using the PFPH-GC/MS method to analyze the composition and the concentration of volatile carbonyl compounds. The emission characteristics and the atmospheric chemical reactivity of these compounds were also studied. The results showed that 20 kinds of carbonyl compounds were detected with a concentration range of 0 to 68.80 microg x m(-3). The mean value of total concentration in all processing unit was (253.02 +/- 124.5) microg x m(-3). Background corrected concentrations showed that for each of the 6 treatment units of the plant, over 90% of the volatile carbonyl emissions were contributed by 14 of the 20 volatile carbonyl compounds, among which aldehyde was the most abundant with an average concentration of (44.74 +/- 20.89) microg x m(-3), followed by 2-butanone and acetaldehyde with average concentrations of (30.47 +/- 12.94) microg x m(-3) and (23.51 +/- 14.57) microg x m(-3), respectively. Several molecular markers were identified based on the analysis of the chemical activities and atmospheric lifetimes of the 20 carbonyl compounds. Finally, a source profile was established for the plant.

  15. Novel DNPH-based method for determination of protein carbonylation in muscle and meat.

    Science.gov (United States)

    Soglia, Francesca; Petracci, Massimiliano; Ertbjerg, Per

    2016-04-15

    Protein oxidation is considered an ongoing deteriorative process during storage of fresh and processed meat. Carbonyl compounds have traditionally been detected spectrophotometrically after derivatization with 2,4-dinitrophenylhydrazine (DNPH) to form protein-bound hydrazones with absorbance at 370 nm. Here we describe a novel DNPH-based method to quantify protein carbonylation in muscle and meat. The additional steps of the novel method aimed at increasing the protein solubility and inducing protein unfolding before labeling with DNPH. Compared to the traditional method, the new procedure reflected an increased protein carbonylation level measuring overall two to fourfold more carbonyls in muscles from different species as well as in soluble, salt-soluble and insoluble protein fractions. The study suggested that protein unfolding is a more important phenomenon than solubilization for increased DNPH labeling. The novel method resulted in three to fourfold larger carbonyl content determined in chicken, pork and beef (2.8, 3.6 and 3.1 nmol/mg of protein, respectively). Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Exchange of carbonyl sulfide (OCS) between soils and atmosphere under various CO2 concentrations

    Science.gov (United States)

    Bunk, Rüdiger; Behrendt, Thomas; Yi, Zhigang; Andreae, Meinrat O.; Kesselmeier, Jürgen

    2017-06-01

    A new continuous integrated cavity output spectroscopy analyzer and an automated soil chamber system were used to investigate the exchange processes of carbonyl sulfide (OCS) between soils and the atmosphere under laboratory conditions. The exchange patterns of OCS between soils and the atmosphere were found to be highly dependent on soil moisture and ambient CO2 concentration. With increasing soil moisture, OCS exchange ranged from emission under dry conditions to an uptake within an optimum moisture range, followed again by emission at high soil moisture. Elevated CO2 was found to have a significant impact on the exchange rate and direction as tested with several soils. There is a clear tendency toward a release of OCS at higher CO2 levels (up to 7600 ppm), which are typical for the upper few centimeters within soils. At high soil moisture, the release of OCS increased sharply. Measurements after chloroform vapor application show that there is a biotic component to the observed OCS exchange. Furthermore, soil treatment with the fungi inhibitor nystatin showed that fungi might be the dominant OCS consumers in the soils we examined. We discuss the influence of soil moisture and elevated CO2 on the OCS exchange as a change in the activity of microbial communities. Physical factors such as diffusivity that are governed by soil moisture also play a role. Comparing KM values of the enzymes to projected soil water CO2 concentrations showed that competitive inhibition is unlikely for carbonic anhydrase and PEPCO but might occur for RubisCO at higher CO2 concentrations.

  17. Carbonyl compounds at Mount Tai in the North China Plain: Characteristics, sources, and effects on ozone formation

    Science.gov (United States)

    Yang, Xue; Xue, Likun; Yao, Lan; Li, Qinyi; Wen, Liang; Zhu, Yanhong; Chen, Tianshu; Wang, Xinfeng; Yang, Lingxiao; Wang, Tao; Lee, Shuncheng; Chen, Jianmin; Wang, Wenxing

    2017-11-01

    Carbonyl compounds, an important category of volatile organic compounds (VOCs), play important roles in ozone (O3) formation and atmospheric chemistry. To better understand the characteristics and sources of carbonyl compounds and their effects on O3 formation, C1-C8 carbonyls were measured at Mount Tai, the highest mountain in the North China Plain (NCP), in summer 2014. Acetone (3.57 ± 0.55 ppbv), formaldehyde (3.48 ± 0.98 ppbv) and acetaldehyde (1.27 ± 0.78 ppbv) are the three most abundant species, comprising as high as 90% of the total observed compounds. Isovaleraldehyde (0.37 ± 0.17 ppbv) presents another important carbonyl compound despite its high reactivity. Comparison with the observations available in China highlights the serious situation of carbonyls pollution in the NCP region. The sources of carbonyls are dominated by photo-oxidation of VOCs during the daytime and regional transport at night. Secondary sources from oxidation of hydrocarbons contribute on average 44% of formaldehyde, 31% of acetone, 85% of acetaldehyde, 78% of benzaldehyde, and 84% of isovaleraldehyde, demonstrating the dominant role of secondary formation in the ambient carbonyl levels. Formaldehyde, acetaldehyde and isovaleraldehyde are the most important contributors to the OH reactivity and O3 production among the measured carbonyls. This study shows that carbonyl compounds contribute significantly to the photochemical pollution in the NCP region and hence understanding their sources and characteristics is essential for developing the science-based O3 pollution control strategies.

  18. Influence of the Dielectric Medium on the Carbonyl Infrared Absorption Peak of Acetylferrocene

    Directory of Open Access Journals (Sweden)

    F. López-Linares

    2005-02-01

    Full Text Available The solvent effect on the position of the carbonyl vibrational stretching ofacetylferrocene in aprotic media was studied in this work. The solvent-induced shifts in thisorganometallic compound were interpreted in terms of the alternative reaction field model(SCRF-MO proposed by Kolling. In contrast to the established trends for carbonyl groupsin organic systems, the results suggest that the continuum models for the reaction field arenot adequate and that the influence of dipolarity-polarizability described by aninhomogeneous coupling function θ (ε L(n 2 that assumes optical dielectric saturation isresponsible for the carbonyl band shift and, there is empirical evidence that the effect offield-induced intermolecular interaction on band shift, interpreted in terms of the van derWaals forces from the solvent, have a important contribution to this phenomena.

  19. Determination of protein carbonyls in plasma, cell extracts, tissue homogenates, isolated proteins

    DEFF Research Database (Denmark)

    Weber, Daniela; Davies, Michael J.; Grune, Tilman

    2015-01-01

    Protein oxidation is involved in regulatory physiological events as well as in damage to tissues and is thought to play a key role in the pathophysiology of diseases and in the aging process. Protein-bound carbonyls represent a marker of global protein oxidation, as they are generated by multiple...... in the most relevant methods to detect protein carbonyls after derivatization with 2,4-dinitrophenylhydrazine with an emphasis on measurement in plasma, cells, organ homogenates, isolated proteins and organelles. Sample preparation, derivatization conditions and protein handling are presented...... for the spectrophotometric and HPLC method as well as for immunoblotting and ELISA. An extensive overview covering these methods in previously published articles is given for researchers who plan to measure protein carbonyls in different samples....

  20. Effect of carbonyl iron particles composition on the physical characteristics of MR grease

    Energy Technology Data Exchange (ETDEWEB)

    Mohamad, Norzilawati, E-mail: mnorzilawati@gmail.com; Mazlan, Saiful Amri, E-mail: amri.kl@utm.my [Vehicle System Engineering, Malaysia – Japan International Institute of Technology, Universiti Teknologi Malaysia, Jalan Sultan Yahya Petra (Jalan Semarak), Kuala Lumpur, 54000 (Malaysia); Ubaidillah, E-mail: ubaidillah@uns.ac.id [Vehicle System Engineering, Malaysia – Japan International Institute of Technology, Universiti Teknologi Malaysia, Jalan Sultan Yahya Petra (Jalan Semarak), Kuala Lumpur, 54000 (Malaysia); Mechanical Engineering Department, Faculty of Engineering, Universitas Sebelas Maret, Jl. Ir. Sutami 36A, Kentingan, Surakarta, 57126, Central Java, Surakarta (Indonesia)

    2016-03-29

    Magnetorheological (MR) grease is an extension of the study of magnetorheological materials. The MR grease can help to reduce the particles sedimentation problem occurred in the MR fluids. Within this study, an effort has been taken to investigate the effect of different weight compositions of carbonyl iron particles on the physical and chemical characteristics of the MR grease under off-state condition (no magnetic field). The MR grease is prepared by mixing carbonyl iron particles having a size range of 1 to 10 µm with commercial NPC Highrex HD-3 grease. Characterizations of MR grease are investigated using Vibrating Sample Magnetometer (VSM), Environmental Scanning Electron Microscopy (ESEM), Differential Scanning Calorimeter (DSC) and rheometer. The dependency of carbonyl iron particles weight towards the magnetic properties of MR grease and other characterizations are investigated.

  1. Cryopreservation of bull semen is associated with carbonylation of sperm proteins.

    Science.gov (United States)

    Mostek, Agnieszka; Dietrich, Mariola Aleksandra; Słowińska, Mariola; Ciereszko, Andrzej

    2017-04-01

    Artificial insemination with cryopreserved semen enables affordable, large-scale dissemination of gametes with superior genetics. However, cryopreservation can cause functional and structural damage to spermatozoa that is associated with reactive oxygen species (ROS) production, impairment of sperm motility and decreased fertilizing potential, but little attention has been paid to protein changes. The goal of this study was to investigate the oxidative modifications (measured as carbonylation level changes) of bull spermatozoa proteins triggered by the cryopreservation process. Flow cytometry and computer-assisted sperm analysis were used to evaluate changes in viability, ROS level and motility of spermatozoa. Western blotting, in conjunction with two-dimensional electrophoresis (2D-oxyblot) and matrix-assisted laser desorption/ionization time-of-flight/time-of-flight spectrometry, was employed to identify and quantify the specifically carbonylated spermatozoa proteins. Cryopreservation decreased motility and viability but increased the number of ROS-positive cells. We identified 11 proteins (ropporin-1, outer dense fiber protein 2, glutathione S-transferase, triosephosphate isomerase, capping protein beta 3 isoform, actin-related protein M1, actin-related protein T2, NADH dehydrogenase, isocitrate dehydrogenase, cilia- and flagella-associated protein 161, phosphatidylethanolamine-binding protein 4) showing differences in protein carbonylation in response to cryopreservation. The identified proteins are associated with cytoskeleton and flagella organization, detoxification and energy metabolism. Moreover, almost all of the identified carbonylated proteins are involved in capacitation. Our results indicate for the first time that cryopreservation induces oxidation of selected sperm proteins via carbonylation. We suggest that carbonylation of sperm proteins could be a direct result of oxidative stress and potentially lead to disturbances of capacitation

  2. Polycyclic Aromatic Hydrocarbons via Iron(III)-Catalyzed Carbonyl-Olefin Metathesis.

    Science.gov (United States)

    McAtee, Christopher C; Riehl, Paul S; Schindler, Corinna S

    2017-03-01

    Polycyclic aromatic hydrocarbons are important structural motifs in organic chemistry, pharmaceutical chemistry, and materials science. The development of a new synthetic strategy toward these compounds is described based on the design principle of iron(III)-catalyzed carbonyl-olefin metathesis reactions. This approach is characterized by its operational simplicity, high functional group compatibility, and regioselectivity while relying on FeCl3 as an environmentally benign, earth-abundant metal catalyst. Experimental evidence for oxetanes as reactive intermediates in the catalytic carbonyl-olefin ring-closing metathesis has been obtained.

  3. First application of supported ionic liquid phase (SILP) catalysis for continuous methanol carbonylation

    DEFF Research Database (Denmark)

    Riisager, Anders; Jørgensen, Betina; Wasserscheid, Peter

    2006-01-01

    A solid, silica-supported ionic liquid phase (SILP) rhodium iodide Monsanto-type catalyst system, [BMIM][Rh(CO)(2)I-2]-[BMIM]I -SiO2, exhibits excellent activity and selectivity towards acetyl products in fixed-bed, continuous gas-phase methanol carbonylation.......A solid, silica-supported ionic liquid phase (SILP) rhodium iodide Monsanto-type catalyst system, [BMIM][Rh(CO)(2)I-2]-[BMIM]I -SiO2, exhibits excellent activity and selectivity towards acetyl products in fixed-bed, continuous gas-phase methanol carbonylation....

  4. Contribution of carbonyl photochemistry to aging of atmospheric secondary organic aerosol

    DEFF Research Database (Denmark)

    Mang, Stephen A.; Henricksen, Dana K.; Bateman, Adam P.

    2008-01-01

    The photodegradation of secondary organic aerosol (SOA) material by actinic UV radiation was investigated. SOA was generated via the dark reaction of ozone and d-limonene, collected onto quartz-fiber filters, and exposed to wavelength-tunable radiation. Photochemical production of CO was monitored...... was measured and compared with the photolysis action spectrum for the release of CO, a marker for Norrish type-1 photocleavage of carbonyls. Both spectra had a band at similar to 300 nm corresponding to the overlapping n -> pi* transitions in nonconjugated carbonyls. The effective extinction coefficient...

  5. Photophysical properties of a synthetic, carbonyl-containing (N=6+CO) carotenoid analogue

    Energy Technology Data Exchange (ETDEWEB)

    Niedzwiedzki, Dariusz M. [Washington Univ., St. Louis, MO (United States)

    2014-05-01

    Retinyl-1 is a synthetic carotenoid analogue belonging to the retinal analogues family. It has six conjugated carbon–carbon double bonds with a carbonyl group conjugated to the π-electron system. Presence of the carbonyl group in vicinity of the conjugated carbon–carbon backbone leads to unique excited state properties that are extremely sensitive to solvent polarity and temperature. The simplicity of the synthesis of Retinyl-1 and ease of attachment to synthetic tetrapyrrole chromophores make Retinyl-1 attractive for use in artificial photosynthetic systems.

  6. Selective Palladium(II)-Catalyzed Carbonylation of Methylene β-C-H Bonds in Aliphatic Amines.

    OpenAIRE

    Cabrera-Pardo, Jaime R; Trowbridge, Aaron; Nappi, Manuel; Ozaki, Kyohei; Gaunt, Matthew James

    2017-01-01

    Pd(II)-catalyzed C–H carbonylation of methylene C–H bonds in secondary aliphatic amines leads to the formation trans-disubstituted β-lactams in excellent yields and selectivities. The generality of the C–H carbonylation process is aided by the action of xantphos-based ligands and is important in securing good yields of the β-lactam products. EPSRC (EP/100548X/1), ERC (ERC-STG-259711), Royal Society (Wolfson Award), Marie Curie Foundation and Herchel Smith Foundation.

  7. Proteome oxidative carbonylation during oxidative stress-induced premature senescence of WI-38 human fibroblasts

    DEFF Research Database (Denmark)

    Le Boulch, Marine; Ahmed, Emad K; Rogowska-Wrzesinska, Adelina

    2017-01-01

    Accumulation of oxidatively damaged proteins is a hallmark of cellular and organismal ageing, and is also a phenotypic feature shared by both replicative senescence and stress-induced premature senescence of human fibroblasts. Moreover, proteins that are building up as oxidized (i.e. the "Oxi......-proteome") during ageing and age-related diseases represent a restricted set of cellular proteins, indicating that certain proteins are more prone to oxidative carbonylation and subsequent intracellular accumulation. The occurrence of specific carbonylated proteins upon oxidative stress induced premature senescence...... to belong to functional interaction networks pointing to signalling pathways that have been implicated in the oxidative stress response and subsequent premature senescence....

  8. 1,3-Dipolar Cycloaddition Reactions of Azomethine Ylides with Carbonyl Dipolarophiles Yielding Oxazolidine Derivatives

    Directory of Open Access Journals (Sweden)

    Adam G. Meyer

    2016-07-01

    Full Text Available We provide a comprehensive account of the 1,3-dipolar cycloaddition reactions of azomethine ylides with carbonyl dipolarophiles. Many different azomethine ylides have been studied, including stabilized and non-stabilized ylides. Of the carbonyl dipolarophiles, aldehydes including formaldehyde are the most studied, although there are now examples of cycloadditions with ketones, ketenes and carboxyl systems, in particular isatoic anhydrides and phthalic anhydrides. Intramolecular cycloadditions with esters can also occur under certain circumstances. The oxazolidine cycloadducts undergo a range of reactions triggered by the ring-opening of the oxazolidine ring system.

  9. Towards the understanding of biogeochemical processes involved in the release of carbonyl sulfide (COS) from soil

    Science.gov (United States)

    Behrendt, Thomas; Catao, Elisa; Bunk, Rüdiger; Yi, Zhigang; Greule, Markus; Keppler, Frank; Kesselmeier, Jürgen; Trumbore, Susan

    2017-04-01

    Carbonyl sulfide (COS) is present in the atmosphere in low mixing ratio ( 500ppt). It is relevant in climate change through the effect in aerosol formation. Soils can act as source of COS, e.g. by microbial degradation of thiocyanate from plant material. On the other side it is known that COS can be consumed via various enzymatic pathways. Assuming that biogenic processes dominate over chemical reactions we extracted nucleic acids and performed amplicon sequencing for bacteria (16S rRNA) and fungi (ITS region) from a mid-latitude agricultural maize soil which was previously incubated under ambient COS and COS fumigation ( 1000ppt). The mixing ratios of COS have been measured online from soil samples in a dynamic chamber system under laboratory conditions by an integrated cavity output spectroscopy (IOCS) analyzer (Los Gatos Research Inc., USA). Additionally stable carbon isotope values (δ13C values) of COS were measured using a pre-concentration method and stable isotope ratio mass spectrometry (IRMS). Under low COS mixing ratio ( 50ppt) δ13C +4.7 ‰ for spruce forest ( 23°C), and -24.4‰ for mid-latitude cornfield ( 22°C), respectively. Linking gas release rates of (COS, CO2, CO, NO) to isotopic signatures of COS and molecular results might allow us to indicate bacterial s-compound degradation related to the higher activity of β-Proteobacteria and of the family Acetobacteraceae from the α-Proteobacteria phylum, potentially involved with the hydrolysis of thiocyanate in the soil releasing COS. Furthermore, our study reports the first COS data for rainforest and desert soils which are in the order of 0.5 pmol gdw-1 h-1 and 2 pmol gdw-1 h-1, respectively.

  10. Litter dominates surface fluxes of carbonyl sulfide in a Californian oak woodland

    Science.gov (United States)

    Sun, Wu; Maseyk, Kadmiel; Lett, Céline; Seibt, Ulli

    2016-02-01

    Carbonyl sulfide (COS) is a promising tracer for partitioning terrestrial photosynthesis and respiration from net carbon fluxes, based on its daytime co-uptake alongside CO2 through leaf stomata. Because ecosystem COS fluxes are the sum of plant and soil fluxes, using COS as a photosynthesis tracer requires accurate knowledge of soil COS fluxes. At an oak woodland in Southern California, we monitored below-canopy surface (soil + litter) COS and CO2 fluxes for 40 days using chambers and laser spectroscopy. We also measured litter fluxes separately and used a depth-resolved diffusion-reaction model to quantify the role of litter uptake in surface COS fluxes. Soil and litter were primarily COS sinks, and mean surface COS uptake was small (˜1 pmol m-2 s-1). After rainfall, uptake rates were higher (6-8 pmol m-2 s-1), and litter contributed a significant fraction (up to 90%) to surface fluxes. We observed rapid concurrent increases in COS uptake and CO2 efflux following the onset of rain. The patterns were similar to the Birch effect widely documented for soils; however, both COS and CO2 flux increases originated mainly in the litter. The synchronous COS-CO2 litter Birch effect indicates that it results from a rapid increase in litter microbial activity after rainfall. We expect that the drying-rewetting cycles typical for mediterranean and other semiarid ecosystems create a pronounced seasonality in surface COS fluxes. Our results highlight that litter uptake is an important component of surface COS exchange that needs to be taken into account in ecosystem COS budgets and model simulations.

  11. Variability of atmospheric carbonyl sulfide at a semi-arid urban site in western India.

    Science.gov (United States)

    Mallik, Chinmay; Chandra, Naveen; Venkataramani, S; Lal, Shyam

    2016-05-01

    Atmospheric carbonyl sulfide (COS) is a major precursor for sulfate aerosols that play a critical role in climate regulation. Recent studies have highlighted the importance of COS measurements as a reliable means to constrain biospheric carbon assimilation. In a scenario of limited availability of COS data around the globe, we present gas-chromatographic measurements of atmospheric COS mixing ratios over Ahmedabad, a semi-arid, urban region in western India. These measurements, being reported for the first time over an Indian site, enable us to understand the diurnal and seasonal variation in atmospheric COS with respect to its natural, anthropogenic and photochemical sources and sinks. The annual mean COS mixing ratio over Ahmedabad is found to be 0.83±0.43ppbv, which is substantially higher than free tropospheric values for the northern hemisphere. Inverse correlation of COS with soil and skin temperature, suggests that the dry soil of the semi-arid study region is a potential sink for atmospheric COS. Positive correlations of COS with NO2 and CO during post-monsoon and the COS/CO slope of 0.78pptv/ppbv reveals influence of diesel combustion and tire wear. The highest concentrations of COS are observed during pre-monsoon; COS/CO2 slope of 44.75pptv/ppmv combined with information from air mass back-trajectories reveal marshy wetlands spanning over 7500km(2) as an important source of COS in Ahmedabad. COS/CO2 slopes decrease drastically (8.28pptv/ppmv) during post-monsoon due to combined impact of biospheric uptake and anthropogenic emissions. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Synthesis of the [beta]-D-glucosyl ester of [carbonyl-[sup 13]C]-indole-3-acetic acid

    Energy Technology Data Exchange (ETDEWEB)

    Jakas, A.; Magnus, V. (Rudjer Boskovic Inst., Zagreb (Croatia)); Horvat, S.; Sandberg, G. (Swedish Univ. of Agricultural Sciences, Uppsala (Sweden))

    1993-10-01

    An efficient, operationally simple synthetic approach to 1-O-([carbonyl-[sup 13]C]-indole-3'-ylacetyl)-[beta]-D-glucopyranose is described. The synthesis was carried out by fusing a fully benzylated 1-O-glucosylpseudourea intermediate with [carbonyl-[sup 13]C]-indole-3-acetic acid, followed by hydrogenolytic removal of the protective groups. (Author).

  13. In situ visualization of carbonylation and its co-localization with proteins, lipids, DNA and RNA in Caenorhabditis elegans.

    Science.gov (United States)

    Kuzmic, Mira; Javot, Hélène; Bonzom, Jean-Marc; Lecomte-Pradines, Catherine; Radman, Miroslav; Garnier-Laplace, Jacqueline; Frelon, Sandrine

    2016-12-01

    All key biological macromolecules are susceptible to carbonylation - an irreparable oxidative damage with deleterious biological consequences. Carbonyls in proteins, lipids and DNA from cell extracts have been used as a biomarker of oxidative stress and aging, but formation of insoluble aggregates by carbonylated proteins precludes quantification. Since carbonylated proteins correlate with and become a suspected cause of morbidity and mortality in some organisms, there is a need for their accurate quantification and localization. Using appropriate fluorescent probes, we have developed an in situ detection of total proteins, DNA, RNA, lipids and carbonyl groups at the level of the whole organism. In C. elegans, we found that after UV irradiation carbonylation co-localizes mainly with proteins and, to a lesser degree, with DNA, RNA and lipids. The method efficiency was illustrated by carbonylation induction assessment over 5 different UV doses. The procedure enables the monitoring of carbonylation in the nematode C. elegans during stress, aging and disease along its life cycle including the egg stage. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Shotgun redox proteomics: identification and quantitation of carbonylated proteins in the UVB-resistant marine bacterium, Photobacterium angustum S14.

    Directory of Open Access Journals (Sweden)

    Sabine Matallana-Surget

    Full Text Available UVB oxidizes proteins through the generation of reactive oxygen species. One consequence of UVB irradiation is carbonylation, the irreversible formation of a carbonyl group on proline, lysine, arginine or threonine residues. In this study, redox proteomics was performed to identify carbonylated proteins in the UVB resistant marine bacterium Photobacterium angustum. Mass-spectrometry was performed with either biotin-labeled or dinitrophenylhydrazide (DNPH derivatized proteins. The DNPH redox proteomics method enabled the identification of 62 carbonylated proteins (5% of 1221 identified proteins in cells exposed to UVB or darkness. Eleven carbonylated proteins were quantified and the UVB/dark abundance ratio was determined at both the protein and peptide levels. As a result we determined which functional classes of proteins were carbonylated, which residues were preferentially modified, and what the implications of the carbonylation were for protein function. As the first large scale, shotgun redox proteomics analysis examining carbonylation to be performed on bacteria, our study provides a new level of understanding about the effects of UVB on cellular proteins, and provides a methodology for advancing studies in other biological systems.

  15. Shotgun redox proteomics: identification and quantitation of carbonylated proteins in the UVB-resistant marine bacterium, Photobacterium angustum S14.

    Science.gov (United States)

    Matallana-Surget, Sabine; Cavicchioli, Ricardo; Fauconnier, Charles; Wattiez, Ruddy; Leroy, Baptiste; Joux, Fabien; Raftery, Mark J; Lebaron, Philippe

    2013-01-01

    UVB oxidizes proteins through the generation of reactive oxygen species. One consequence of UVB irradiation is carbonylation, the irreversible formation of a carbonyl group on proline, lysine, arginine or threonine residues. In this study, redox proteomics was performed to identify carbonylated proteins in the UVB resistant marine bacterium Photobacterium angustum. Mass-spectrometry was performed with either biotin-labeled or dinitrophenylhydrazide (DNPH) derivatized proteins. The DNPH redox proteomics method enabled the identification of 62 carbonylated proteins (5% of 1221 identified proteins) in cells exposed to UVB or darkness. Eleven carbonylated proteins were quantified and the UVB/dark abundance ratio was determined at both the protein and peptide levels. As a result we determined which functional classes of proteins were carbonylated, which residues were preferentially modified, and what the implications of the carbonylation were for protein function. As the first large scale, shotgun redox proteomics analysis examining carbonylation to be performed on bacteria, our study provides a new level of understanding about the effects of UVB on cellular proteins, and provides a methodology for advancing studies in other biological systems.

  16. Seasonal, diurnal and nocturnal variations of carbonyl compounds in the semi-urban environment of Orléans, France.

    Science.gov (United States)

    Jiang, Zhaohui; Grosselin, Benoît; Daële, Véronique; Mellouki, Abdelwahid; Mu, Yujing

    2016-02-01

    Atmospheric carbonyls were measured at a semi-urban site in Orléans, France, from October 2010 to July 2011. Formaldehyde, acetaldehyde and acetone were found to be the most abundant carbonyls, with average concentrations of 3.1, 1.0, 2.0 ppb, respectively in summer, 2.3, 0.7, 2.2 ppb, respectively in autumn, 2.2, 1.0, 2.1 ppb, respectively in spring, and 1.5, 0.7, 1.1 ppb, respectively in winter. Photo-oxidation of volatile organic compounds (VOCs) was found to make a remarkable contribution to atmospheric carbonyls in the semi-urban site based on the distinct seasonal and diurnal variations of the carbonyls, as well as the significantly positive correlations between the carbonyls and ozone. The significantly negative correlations between NOx and O3 as well as the carbonyls and the positive correlations between wind speed and O3 as well as the carbonyls implied that the carbonyls and O3 at the semi-urban site were probably formed during air mass transport from neighboring cities. Copyright © 2015. Published by Elsevier B.V.

  17. Modular Approach for Novel Nanostructered Polycondensates Enabled by the Unique Selectivity of Carbonyl Biscaprolactam

    NARCIS (Netherlands)

    Loontjens, Ton

    2003-01-01

    New enabling chemistries have been developed to produce novel well-defined polymeric materials through the additions of small amounts of reactive functional compounds to standard polymers during regular processing steps. We found that carbonyl biscaprolactam and its derivatives couple polymer chains

  18. Efficient and selective α-bromination of carbonyl compounds with N-bromosuccinimide under microwave

    Directory of Open Access Journals (Sweden)

    Xiao-Yu Guan

    2015-11-01

    Full Text Available A highly efficient method for the synthesis of α-halocarbonyl compounds has been achieved via selective monobromination of aromatic and aliphatic carbonyl compounds with N-bromosuccinimide catalyzed by p-toluenesulfonic acid under microwave irradiation within 30 min.

  19. One-pot Reductive Amination of Carbonyl Compounds with NaBH₄ ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 129; Issue 1. One-pot Reductive Amination of Carbonyl Compounds with NaBH₄-B(OSO₃H)₃/SiO₂ in Acetonitrile and in Solvent-free Condition. HOSEIN HAMADI SAMIRA JAVADI. Regular Article Volume 129 Issue 1 January 2017 pp 75-80 ...

  20. Enantioselective α-Arylation of Carbonyls via Cu(I)-Bisoxazoline Catalysis

    Science.gov (United States)

    Harvey, James S.; Simonovich, Scott P.; Jamison, Christopher R.; MacMillan, David W. C.

    2011-01-01

    The enantioselective α-arylation of both lactones and acyl oxazolidones has been accomplished using a combination of diaryliodonium salts and copper catalysis. These mild catalytic conditions provide a new strategy for the enantioselective construction and retention of enolizable α-carbonyl benzylic stereocenters, a valuable synthon for the production of medicinal agents. PMID:21848265

  1. Direct photolysis of carbonyl compounds dissolved in cloud and fog~droplets

    Science.gov (United States)

    Epstein, S. A.; Tapavicza, E.; Furche, F.; Nizkorodov, S. A.

    2013-09-01

    Gas-phase photolysis is an important tropospheric sink for many carbonyl compounds; however the significance of direct photolysis of these compounds dissolved in cloud and fog droplets is uncertain. We develop a theoretical approach to assess the importance of aqueous photolysis for a series of carbonyls that possess carboxyl and hydroxyl functional groups by comparison with rates of other atmospheric processes. We use computationally and experimentally derived effective Henry's law constants, hydration equilibrium parameters, aqueous hydroxyl radical (OH) rate constants, and optical extinction coefficients to identify types of compounds that will (or will not) have competitive aqueous photolysis rates. We also present molecular dynamics simulations designed to estimate gas- and aqueous-phase extinction coefficients of unstudied atmospherically relevant compounds found in d-limonene and isoprene secondary organic aerosol. In addition, experiments designed to measure the photolysis rate of glyceraldehyde, an atmospherically relevant water-soluble organic compound, reveal that aqueous quantum yields are highly molecule-specific and cannot be extrapolated from measurements of structurally similar compounds. We find that only two out of the 92 carbonyl compounds investigated, pyruvic acid and acetoacetic acid, may have aqueous photolysis rates that exceed the rate of oxidation by dissolved OH. For almost all carbonyl compounds lacking α,β-conjugation that were investigated, atmospheric removal by direct photolysis in cloud and fog droplets can be neglected under typical atmospheric conditions.

  2. Direct photolysis of carbonyl compounds dissolved in cloud and fog~droplets

    Directory of Open Access Journals (Sweden)

    S. A. Epstein

    2013-09-01

    Full Text Available Gas-phase photolysis is an important tropospheric sink for many carbonyl compounds; however the significance of direct photolysis of these compounds dissolved in cloud and fog droplets is uncertain. We develop a theoretical approach to assess the importance of aqueous photolysis for a series of carbonyls that possess carboxyl and hydroxyl functional groups by comparison with rates of other atmospheric processes. We use computationally and experimentally derived effective Henry's law constants, hydration equilibrium parameters, aqueous hydroxyl radical (OH rate constants, and optical extinction coefficients to identify types of compounds that will (or will not have competitive aqueous photolysis rates. We also present molecular dynamics simulations designed to estimate gas- and aqueous-phase extinction coefficients of unstudied atmospherically relevant compounds found in d-limonene and isoprene secondary organic aerosol. In addition, experiments designed to measure the photolysis rate of glyceraldehyde, an atmospherically relevant water-soluble organic compound, reveal that aqueous quantum yields are highly molecule-specific and cannot be extrapolated from measurements of structurally similar compounds. We find that only two out of the 92 carbonyl compounds investigated, pyruvic acid and acetoacetic acid, may have aqueous photolysis rates that exceed the rate of oxidation by dissolved OH. For almost all carbonyl compounds lacking α,β-conjugation that were investigated, atmospheric removal by direct photolysis in cloud and fog droplets can be neglected under typical atmospheric conditions.

  3. Ketene as a Reaction Intermediate in the Carbonylation of Dimethyl Ether to Methyl Acetate over Mordenite

    DEFF Research Database (Denmark)

    Rasmussen, Dominik Bjørn; Christensen, Jakob Munkholt; Temel, Burcin

    2015-01-01

    Unprecedented insight into the carbonylation of dimethyl ether over Mordenite is provided through the identification of ketene (CH2CO) as a reaction intermediate. The formation of ketene is predicted by detailed DFT calculations and verified experimentally by the observation of doubly deuterated ...

  4. [pi] Backbonding in Carbonyl Complexes and Carbon-Oxygen Stretching Frequencies: A Molecular Modeling Exercise

    Science.gov (United States)

    Montgomery, Craig D.

    2007-01-01

    An exercise is described that has illustrated the effect of various factors on [pi] backbonding to carbonyl ligands, where the students can view the molecular orbitals corresponding to the M-CO [pi] interaction as well as the competing interaction between the metal and co-ligands. The visual and hands-on nature of the modeling exercise has helped…

  5. Infrared Spectroscopy and Structures of Cobalt Carbonyl Cations, Co(CO)(n)(+) (n=1-9)

    NARCIS (Netherlands)

    Ricks, A. M.; Bakker, J. M.; Douberly, G. E.; Duncan, M. A.

    2009-01-01

    Cobalt carbonyl cations of the form Co(CO)(n)(+) (n = 1-9) are produced in a molecular beam by laser vaporization in a pulsed nozzle source. These ions, and their corresponding "argon-tagged" analogues, Co(CO)(n)(Ar)(m)(+), are studied with mass-selected infrared photodissociation

  6. Additive role of attapulgite nanoclay on carbonyl iron-based magnetorheological suspension

    CSIR Research Space (South Africa)

    Chae, HS

    2014-09-01

    Full Text Available Attapulgite (ATP), a fibrous nanoclay mineral, was adopted as an additive in this study to improve the sedimentation problem of soft magnetic carbonyl iron (CI)-based magnetorheological (MR) fluids caused by the density mismatch between the CI...

  7. Canopy uptake dominates nighttime carbonyl sulfide fluxes in a boreal forest

    NARCIS (Netherlands)

    Kooijmans, Linda MJ; Maseyk, Kadmiel; Seibt, Ulli; Sun, Wu; Vesala, Timo; Mammarella, Ivan; Kolari, Pasi; Aalto, Juho; Franchin, Alessandro; Vecchi, Roberta; Valli, Gianluigi; Chen, Huilin

    2017-01-01

    Nighttime vegetative uptake of carbonyl sulfide (COS) can exist due to the incomplete closure of stomata and the light independence of the enzyme carbonic anhydrase, which complicates the use of COS as a tracer for gross primary productivity (GPP). In this study we derived night-time COS fluxes in a

  8. Oxalyl chloride as a practical carbon monoxide source for carbonylation reactions

    DEFF Research Database (Denmark)

    Hansen, Steffen V F; Ulven, Trond

    2015-01-01

    A method for generation of high-quality carbon monoxide by decomposition of oxalyl chloride in an aqueous hydroxide solution is described. The usefulness of the method is demonstrated in the synthesis of heterocycles and for hydroxy-, alkoxy-, amino-, and reductive carbonylation reactions...

  9. Palladium-catalyzed carbonylative sonogashira coupling of aryl bromides using near stoichiometric carbon monoxide

    DEFF Research Database (Denmark)

    Neumann, Karoline T.; Laursen, Simon R.; Lindhardt, Anders T.

    2014-01-01

    A general procedure for the palladium-catalyzed carbonylative Sonogashira coupling of aryl bromides is reported, using near stoichiometric amounts of carbon monoxide. The method allows a broad substrate scope in moderate to excellent yields. The formed alkynone motive serves as a platform...

  10. Magnetic Silica-Supported Ruthenium Nanoparticles: An Efficient Catalyst for Transfer Hydrogenation of Carbonyl Compounds

    Science.gov (United States)

    One-pot synthesis of ruthenium nanoparticles on magnetic silica is described which involve the in situ generation of magnetic silica (Fe3O4@ SiO2) and ruthenium nano particles immobilization; the hydration of nitriles and transfer hydrogenation of carbonyl compounds occurs in hi...

  11. Contribution of carbonyl photochemistry to aging of atmospheric secondary organic aerosol.

    Science.gov (United States)

    Mang, Stephen A; Henricksen, Dana K; Bateman, Adam P; Andersen, Mads P Sulbaek; Blake, Donald R; Nizkorodov, Sergey A

    2008-09-11

    The photodegradation of secondary organic aerosol (SOA) material by actinic UV radiation was investigated. SOA was generated via the dark reaction of ozone and d-limonene, collected onto quartz-fiber filters, and exposed to wavelength-tunable radiation. Photochemical production of CO was monitored in situ by infrared cavity ring-down spectroscopy. A number of additional gas-phase products of SOA photodegradation were observed by gas chromatography, including methane, ethene, acetaldehyde, acetone, methanol, and 1-butene. The absorption spectrum of SOA material collected onto CaF2 windows was measured and compared with the photolysis action spectrum for the release of CO, a marker for Norrish type-I photocleavage of carbonyls. Both spectra had a band at approximately 300 nm corresponding to the overlapping n --> pi* transitions in nonconjugated carbonyls. The effective extinction coefficient of freshly prepared SOA was estimated to be on the order of 15 L mol(-1) cm(-1) at 300 nm, implying one carbonyl group in every SOA constituent. The absorption by the SOA material slowly increased in the visible and near-UV during storage of SOA in open air in the dark, presumably as a result of condensation reactions that increased the degree of conjugation in the SOA constituents. These observations suggest that photolysis of carbonyl functional groups represents a significant sink for monoterpene SOA compounds in the troposphere, with an estimated lifetime of several hours over the continental United States.

  12. Iron Dextran treatment does not induce serum protein carbonyls in the newborn pig

    Science.gov (United States)

    Oxidation of serum proteins can lead to carbonyl formation which alters their function and is often associated with stress-related diseases. Since it is recommended that all pigs reared in modern production facilities be given supplemental iron at birth to prevent anemia, and metals can catalyze th...

  13. Proteomic and carbonylation profile analysis of rat skeletal muscles following acute swimming exercise.

    Directory of Open Access Journals (Sweden)

    Francesca Magherini

    Full Text Available Previous studies by us and other groups characterized protein expression variation following long-term moderate training, whereas the effects of single bursts of exercise are less known. Making use of a proteomic approach, we investigated the effects of acute swimming exercise (ASE on protein expression and carbonylation patterns in two hind limb muscles: the Extensor Digitorum Longus (EDL and the Soleus, mostly composed of fast-twitch and slow-twitch fibres, respectively. Carbonylation is one of the most common oxidative modifications of proteins and a marker of oxidative stress. In fact, several studies suggest that physical activity and the consequent increase in oxygen consumption can lead to increase in reactive oxygen and nitrogen species (RONS production, hence the interest in examining the impact of RONS on skeletal muscle proteins following ASE. Results indicate that protein expression is unaffected by ASE in both muscle types. Unexpectedly, the protein carbonylation level was reduced following ASE. In particular, the analysis found 31 and 5 spots, in Soleus and EDL muscles respectively, whose carbonylation is reduced after ASE. Lipid peroxidation levels in Soleus were markedly reduced as well. Most of the decarbonylated proteins are involved either in the regulation of muscle contractions or in the regulation of energy metabolism. A number of hypotheses may be advanced to account for such results, which will be addressed in future studies.

  14. Enantioselective gamma- and delta-Borylation of Unsaturated Carbonyl Derivatives: Synthesis, Mechanistic Insights, and Applications

    Science.gov (United States)

    Hoang, Gia L.

    Chiral boronic esters are valuable synthetic intermediates widely used in a variety of stereospecific transformations. Transition metal-catalyzed asymmetric hydroboration (CAHB) of alkenes is among the most popular methods for their preparation. Enantioselective hydroboration of activated alkenes (i.e., vinyl arene derivatives or conjugated carbonyl compounds) have been extensively studied by many research groups. We, on the other hand, are interested in enantioselective hydroboration of unactivated alkenes utilizing coordinating functional groups (e.g., carbonyl derivatives) to give functionalized, chiral boronic esters. While conjugate addition and C-H activation methodologies provide efficient alternatives to CAHB for enantioselective beta-borylation of carbonyl compounds, direct gamma- and delta-borylations were essentially unknown prior to our wok on CAHB. The gamma-borylated products were used for understanding stereochemical aspects of Suzuki-Miyaura cross-coupling reactions resulting in stereoretention and in contrast to similar beta-borylated carbonyl derivatives reported in literature. Some other selected transformations were carried out to construct a number of biologically relevant structural motifs, such as lignan precursors, 1,4-amino alcohols, gamma-amino acid derivatives, 5-substitued-gamma-lactone and lactam ring systems. In addition, collaborative experimental and computational studies of the enantioselective desymmetrization via CAHB gain a better understanding of the mechanistic pathways.

  15. NMR Studies of Structure-Reactivity Relationships in Carbonyl Reduction: A Collaborative Advanced Laboratory Experiment

    Science.gov (United States)

    Marincean, Simona; Smith, Sheila R.; Fritz, Michael; Lee, Byung Joo; Rizk, Zeinab

    2012-01-01

    An upper-division laboratory project has been developed as a collaborative investigation of a reaction routinely taught in organic chemistry courses: the reduction of carbonyl compounds by borohydride reagents. Determination of several trends regarding structure-activity relationship was possible because each student contributed his or her results…

  16. Cobalt-catalysed C-H carbonylative cyclisation of aliphatic amides.

    Science.gov (United States)

    Williamson, Patrick; Galván, Alicia; Gaunt, Matthew J

    2017-04-01

    A cobalt-catalysed C-H carbonylation of aliphatic carboxamide derivatives is described, employing commercially available Co(ii)-salts in the presence of a silver oxidant. This operationally simple process utilises an atmospheric pressure of CO and generates a range of substituted succinimide products bearing diverse functional groups that can be successfully accessed via this methodology.

  17. Levels, sources and health risks of carbonyls and BTEX in the ambient air of Beijing, China.

    Science.gov (United States)

    Zhang, Yujie; Mu, Yujing; Liu, Junfeng; Mellouki, Abdelwahid

    2012-01-01

    The atmospheric concentrations of carbonyls and BTEX (benzene, toluene, ethylbenzene, m,p-xylene and o-xylene) were measured simultaneously at a same sampling site in Beijing from September 2008 to August 2010. The average concentrations of the total measured carbonyls during autumn, winter, spring, and summer were 37.7, 31.3, 39.7, 50.5 microg/m3, respectively, and maximal values for their diurnal variations usually happened at noontime. In contrast to carbonyls, the average concentrations of the total measured BTEX during the four seasons were 27.2, 31.9, 23.2, 19.1 microg/m3, respectively, and minimal values for their diurnal variations always occurred in the early afternoon. The average concentration for carbonyls increased about 24% from September 2008-August 2009 to September 2009-August 2010, for BTEX, increased about 15%. Integrated life time cancer risks for three carcinogens (benzene, formaldehyde and acetaldehyde) in Beijing exceeded the value of 1E-06, and the hazard quotient (HQ) of non-cancer risk of exposure to formaldehyde exceeded unity.

  18. Higher education

    OpenAIRE

    Wolter, Andrä

    2009-01-01

    During the last five years higher education research in Germany seems to be in a significant upturn. This is a side effect partly of the obvious boom of empirical educational research in general and partly of the reform movement that has affected the German higher education system since middle of the 1990s. The demand for data in the field of higher education will increase considerably in future. The available data infrastructure for higher education research in Germany consists of two comple...

  19. Preparation and characterization of carbonyl iron/poly(butylcyanoacrylate) core/shell nanoparticles.

    Science.gov (United States)

    Arias, J L; Gallardo, V; Linares-Molinero, F; Delgado, A V

    2006-07-15

    In this article a method is described to prepare composite colloidal nanoparticles, consisting of a magnetic core (carbonyl iron) and a biodegradable polymeric shell [poly(butylcyanoacrylate) or PBCA]. The method is based on the so-called anionic polymerization procedure, often used in the synthesis of poly(alkylcyanoacrylate) nanospheres designed for drug delivery. Interest of this investigation is based upon the fact that the heterogeneous structure of the particles can confer them both the possibility to respond to external magnetic fields and to be used as drug carriers. In order to investigate to what extent do the particles participate of this mixed properties, we compare in this work the physical characteristics (structure, chemical composition, specific surface area and surface electrical and thermodynamic properties) of the core/shell particles with those of both the nucleus and the coating material. This preliminary study shows that the mixed particles display an intermediate behavior between that of carbonyl iron and PBCA spheres. Electrophoretic mobility measurements as a function of pH and as a function of KNO3 concentration, show a great similarity between the core/shell and pure polymer nanoparticles. Similarly, a surface thermodynamic study performed on the three types of particles demonstrated that the electron-donor component of the surface free energy of the solids is very sensitive to the surface composition. In fact, a measurable decrease of such component is found for core/shell particles as compared to carbonyl iron. We also analyzed the influence of the relative amounts of polymer and carbonyl iron on the characteristics of the composite particles: data on the coating thickness, the amount of polymer bound to the magnetic nuclei, the redispersibility characteristics of the suspensions and the surface electrical and thermodynamic properties, suggest that the optimal synthesis conditions are obtained for a 4/3 initial monomer/carbonyl iron

  20. Gas-phase chemistry of Mo, Ru, W, and Os metal carbonyl complexes

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Y.; Qin, Z.; Fan, F.L. [Chinese Academy of Sciences, Lanzhou (China). Inst. of Modern Physics; and others

    2014-04-01

    Metal carbonyl complexes were used for studying the gas-phase chemical behavior of Mo, Ru, W and Os isotopes with an on-line low temperature isothermal gas chromatography apparatus. Short-lived Mo and Ru isotopes were produced by a {sup 252}Cf spontaneous fission source. Short-lived nuclides of W and Os were produced using the heavy ion reactions {sup 19}F + {sup 159}Tb and {sup 165}Ho, respectively. Short-lived products were thermalized in a recoil chamber filled with a gas mixture of helium and carbon monoxide. The carbonyls formed were then transported through capillaries to an isothermal chromatography column for study of the adsorption behavior as a function of temperature. On-line isothermal chromatography (IC) experiments on Teflon (PTFE) and quartz surfaces showed that short-lived isotopes of the listed elements can form carbonyl complexes which are very volatile and interact most likely in physical sorption processes. Deduced adsorption enthalpies of Mo and Ru carbonyls were -38 ± 2 kJ/mol and -36 ± 2 kJ/mol, respectively. These values are in good agreement with literature data, partly obtained with different chromatographic techniques. A validation of the applied Monte Carlo model to deduce adsorption enthalpies with Mo isotopes of different half-lives proved the validity of the underlying adsorption model. The investigations using a gas-jet system coupled to a heavy ion accelerator without any preseparator clearly showed the limitations of the approach. The He and CO gas mixture, which was directly added into the chamber, will result in decomposition of CO gas and produce some aerosol particles. After the experiment of {sup 173}W and {sup 179}Os in the heavy ion experiments, the Teflon column was covered by a yellowish deposit; the adsorption enthalpy of W and Os carbonyls could therefore not be properly deduced using Monte Carlo simulations. (orig.)

  1. Spatial distributions of airborne di-carbonyls in urban and rural areas in China

    Science.gov (United States)

    Lui, K. H.; Dai, Wen-Ting; Chan, C. S.; Ho, Steven Sai Hang; Cao, Jun-Ji; Lee, S. C.; Ho, K. F.

    2017-04-01

    Gaseous glyoxal and methylglyoxal concentrations were characterized in nine cities of China during 2010-2011. The average summer (winter) glyoxal and methylglyoxal concentrations were 36.4-178.4 (12.3-241.4) and 67.8-359.4 (28.4-530.0) ng/m3, respectively. In summer, the highest average glyoxal concentration was in Guangzhou (GZ), while the lowest was in Shanghai (SH). In winter, Xiamen (XM) showed the highest average methylglyoxal concentration and Yantai (YT) reported the lowest. Both di-carbonyls showed distinct seasonal variations. The maximum average methylglyoxal concentration was approximately twice as much as glyoxal, which is consistent with the results of other studies. Glyoxal-to-methylglyoxal ratios showed that there was a consistent direct source of emissions in remote areas such as Qinghai Lake and Lhasa in both seasons (r ≥ 0.9). Pearson's correlation analysis suggested possible similar sources formation (R ≥ 0.7) for the two di-carbonyls in winter. Multiple linear regression analyses demonstrated that every 1 °C temperature increase could lead to a > 2% increase in the concentration of the di-carbonyls in both seasons. There was a greater percentage gain for glyoxal in winter than in summer for the same temperature increase. The northeast monsoon occurs in winter, and for every 1 ms- 1 increase in wind speed, > 20% of the di-carbonyls can be transferred out of China. This study is useful to understand about the secondary organic aerosol formation in the areas, the statistical analysis can provide information about the relationships between these carbonyls in atmosphere.

  2. Infrared and reflectron time-of-flight mass spectroscopic analysis of methane (CH4)-carbon monoxide (CO) ices exposed to ionization radiation--toward the formation of carbonyl-bearing molecules in extraterrestrial ices.

    Science.gov (United States)

    Kaiser, Ralf I; Maity, Surajit; Jones, Brant M

    2014-02-28

    Ice mixtures of methane and carbon monoxide were exposed to ionizing radiation in the form of energetic electrons at 5.5 K to investigate the formation of carbonyl bearing molecules in extraterrestrial ices. The radiation induced chemical processing of the mixed ices along with their isotopically labeled counterparts was probed online and in situ via infrared spectroscopy (solid state) aided with reflectron time-of-flight mass spectrometry (ReTOFMS) coupled to single photon photoionization (PI) at 10.49 eV (gas phase). Deconvolution of the carbonyl absorption feature centered at 1727 cm(-1) in the processed ices and subsequent kinetic fitting to the temporal growth of the newly formed species suggests the formation of acetaldehyde (CH3CHO) together with four key classes of carbonyl-bearing molecules: (i) alkyl aldehydes, (ii) alkyl ketones, (iii) α,β-unsaturated ketones/aldehydes and (iv) α,β,γ,δ-unsaturated ketones/α,β-dicarbonyl compounds in keto-enol form. The mechanistical studies indicate that acetaldehyde acts as the key building block of higher aldehydes (i) and ketones (ii) with unsaturated ketones/aldehydes (iii) and/or α,β-dicarbonyl compounds (iv) formed from the latter. Upon sublimation of the newly synthesized molecules, ReTOFMS together with isotopic shifts of the mass-to-charge ratios was exploited to identify eleven product classes containing molecules with up to six carbon atoms, which can be formally derived from C1-C5 hydrocarbons incorporating up to three carbon monoxide building blocks. The classes are (i) saturated aldehydes/ketones, (ii) unsaturated aldehydes/ketones, (iii) doubly unsaturated aldehydes/ketones, (iv) saturated dicarbonyls (aldehydes/ketones), (v) unsaturated dicarbonyls (aldehydes/ketones), (vi) saturated tricarbonyls (aldehydes/ketones), molecules containing (vii) one carbonyl - one alcohol (viii), two carbonyls - one alcohol, (ix) one carbonyl - two alcohol groups along with (x) alcohols and (xi) diols. Reaction

  3. Surface functionalization of carbonyl iron with aluminum phosphate coating toward enhanced anti-oxidative ability and microwave absorption properties

    Science.gov (United States)

    Duan, Wenju; Li, Xuandong; Wang, Ying; Qiang, Rong; Tian, Chunhua; Wang, Na; Han, Xijiang; Du, Yunchen

    2018-01-01

    Fe@AlPO4 core-shell composites with tunable AlPO4 content have been successfully prepared through in situ deposition of AlPO4 on the surface of carbonyl iron. The presence of the AlPO4 layer improves the anti-oxidative ability of the internal carbonyl iron, so that surface oxidation and magnetic degradation in these composites are significantly suppressed when compared with naked carbonyl iron. It is worth noting that the AlPO4 layer can affect the electromagnetic parameters of carbonyl iron, resulting in well-matched characteristic impedance. By optimizing the AlPO4 layer content, the Fe@AlPO4 composite can display excellent reflection loss characteristics, and qualified absorption in a very broad frequency range (2.4-18.0 GHz over -10 dB) can be achieved. The microwave absorption performance of the Fe@AlPO4 composite is indeed superior to pure carbonyl iron as well as many previously reported carbonyl iron-based composites. More importantly, the Fe@AlPO4 composite can maintain good microwave absorption properties after treatment at high temperature for long time periods. These results provide new insight into the fabrication of carbonyl iron-based composites with good microwave absorption and anti-oxidative properties that meet the requirements in practical applications.

  4. PAH, BTEX, carbonyl compound, black-carbon, NO2 and ultrafine particle dynamometer bench emissions for Euro 4 and Euro 5 diesel and gasoline passenger cars

    Science.gov (United States)

    Louis, Cédric; Liu, Yao; Tassel, Patrick; Perret, Pascal; Chaumond, Agnès; André, Michel

    2016-09-01

    Although implementing Diesel particulate filters (DPF) and other novel aftertreatment technologies makes it possible to achieve significant reductions in particle mass emissions, it may induce the release of ultrafine particles and emissions of many other unregulated compounds. This paper focuses on (i) ultrafine particles, black carbon, BTEX, PAH, carbonyl compounds, and NO2 emissions from Euro 4 and Euro 5 Diesel and gasoline passenger cars, (ii) the influence of driving conditions (e.g., cold start, urban, rural and motorway conditions), and (iii) the impact of additive and catalysed DPF devices on vehicle emissions. Chassis dynamometer tests were conducted on four Euro 5 vehicles and two Euro 4 vehicles: gasoline vehicles with and without direct injection system and Diesel vehicles equipped with additive and catalysed particulate filters. The results showed that compared to hot-start cycles, cold-start urban cycles increased all pollutant emissions by a factor of two. The sole exception was NO2, which was reduced by a factor of 1.3-6. Particulate and black carbon emissions from the gasoline engines were significantly higher than those from the Diesel engines equipped with DPF. Moreover, the catalysed DPF emitted about 3-10 times more carbonyl compounds and particles than additive DPF, respectively, during urban driving cycles, while the additive DPF vehicles emitted 2 and 5 times more BTEX and carbonyl compounds during motorway driving cycles. Regarding particle number distribution, the motorway driving cycle induced the emission of particles smaller in diameter (mode at 15 nm) than the urban cold-start cycle (mode at 80-100 nm). The results showed a clear positive correlation between particle, black carbon, and BTEX emissions, and a negative correlation between particles and NO2.

  5. The mycotoxin patulin reacts with DNA bases with and without previous conjugation to GSH: implication for related α,β-unsaturated carbonyl compounds?

    Science.gov (United States)

    Pfenning, Carolin; Esch, Harald L; Fliege, Ralph; Lehmann, Leane

    2016-02-01

    The α,β-unsaturated carbonyl group is recognized as alert for mutagenicity, attributed to (1) its direct reaction with DNA, counteractable by glutathione (GSH), and (2) oxidative stress caused indirectly by GSH depletion. Accordingly, the α,β,γ,δ-unsaturated lactone patulin (PAT), a mycotoxin detected in fruits and products derived thereof, is known to induce gene, chromosome, and genome mutations in vitro, its mutagenicity correlating inversely with intracellular GSH levels. Thus, the reactivity of PAT against DNA bases and nucleosides in the absence and presence of GSH and glutathione S-transferases (GSTs) was investigated under cell-free conditions using HPLC mass spectrometry techniques for identification of reaction products. Adduct formation with all four nucleobases as well as with purine base nucleosides occurred even in the presence of GSH, revealing several adducts of PAT, mono- and disubstituted with nucleobases/nucleosides as well as novel GSH-PAT adducts. In addition, novel mixed GSH-PAT-nucleobase adducts were observed. These adducts exhibited a ketohexanoic acid-type structure of the PAT molecule, C6 substituted with GSH and linking C1 of PAT with nitrogens of nucleobases/nucleosides via an amide bond. Formation of GSH-PAT-adenine adducts was not prevented by GSTs, and excess of GSH needed to reduce their formation was higher than for PAT-adenine adducts. The formation of mixed GSH-DNA base adducts has not been described for PAT or any other α,β-unsaturated carbonyl before, although the reaction mechanism seems to be applicable to a variety of α,β-unsaturated carbonyls occurring in food and in the environment.

  6. Recherches récentes sur le cobalt carbonyle et ses dérivés Recent Studies of Cobalt Carbonyl and Its Derivatives

    Directory of Open Access Journals (Sweden)

    Poilblanc R.

    2006-11-01

    Full Text Available Faisant le point sur l'ensemble de leurs résultats obtenus au cours des dernières années, les auteurs développent divers aspects relatifs aux synthèses, à la physico-chimie et aux structures des complexes dérivés des cobalt carbonyle. L'étude concerne essentiellement : - les dérivés de simple substitution de l'octacarbonyle dicobalt et la tautomérie des complexes dinucléaires; - les dérivés mononucléaires ioniques et leur relation avec les formes alkyle et acétyle du cobalt (I; - le bis (tétracarbonyle cobalt mercure et ses dérivés de substitution ; - les dérivés tétranucléaires et le phénomène de « migration intramoléculaire » des ligands. Les caractéristiques spectrographiques de quelque soixante-dix complexes sont fournies en annexe. The authors review their findings concerning the synthesis, physico-chemical properties and structural nature of cobalt carbonyl derivatives. The article deals with : - Normal substitution of Col (CO,, and tautomerism of binuclear complexes; - lonic mononuclear derivatives in relation with alkyl and acetylcobaltcarbonyls ; - Bis (tetracarbonylcobalt mercury and its substituted derivatives ; - Tetranuclear cobalt complexes exhibiting intramolecular scrambling. Spectrographic data of some 70 compounds are given.

  7. Global carbonyl sulfide (OCS) measured by MIPAS/Envisat during 2002-2012

    Science.gov (United States)

    Glatthor, Norbert; Höpfner, Michael; Leyser, Adrian; Stiller, Gabriele P.; von Clarmann, Thomas; Grabowski, Udo; Kellmann, Sylvia; Linden, Andrea; Sinnhuber, Björn-Martin; Krysztofiak, Gisèle; Walker, Kaley A.

    2017-02-01

    We present a global carbonyl sulfide (OCS) data set covering the period June 2002 to April 2012, derived from FTIR (Fourier transform infrared) limb emission spectra measured with the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) on the ENVISAT satellite. The vertical resolution is 4-5 km in the height region 6-15 km and 15 at 40 km altitude. The total estimated error amounts to 40-50 pptv between 10 and 20 km and to 120 pptv at 40 km altitude. MIPAS OCS data show no systematic bias with respect to balloon observations, with deviations mostly below ±50 pptv. However, they are systematically higher than the OCS volume mixing ratios of the ACE-FTS instrument on SCISAT, with maximum deviations of up to 100 pptv in the altitude region 13-16 km. The data set of MIPAS OCS exhibits only moderate interannual variations and low interhemispheric differences. Average concentrations at 10 km altitude range from 480 pptv at high latitudes to 500-510 pptv in the tropics and at northern mid-latitudes. Seasonal variations at 10 km altitude amount to up to 35 pptv in the Northern and up to 15 pptv in the Southern Hemisphere. Northern hemispheric OCS abundances at 10 km altitude peak in June in the tropics and around October at high latitudes, while the respective southern hemispheric maxima were observed in July and in November. Global OCS distributions at 250 hPa (˜ 10-11 km) show enhanced values at low latitudes, peaking during boreal summer above the western Pacific and the Indian Ocean, which indicates oceanic release. Further, a region of depleted OCS amounts extending from Brazil to central and southern Africa was detected at this altitude, which is most pronounced in austral summer. This depletion is related to seasonally varying vegetative uptake by the tropical forests. Typical signatures of biomass burning like the southern hemispheric biomass burning plume are not visible in MIPAS data, indicating that this process is only a minor source of upper

  8. Design and fabrication of microfluidic mixer from carbonyl iron–PDMS composite membrane

    KAUST Repository

    Li, Jiaxing

    2010-10-12

    This paper introduces a carbonyl iron-PDMS (CI-PDMS) composite magnetic elastomer in which carbonyl iron (CI) particles are uniformly distributed in a PDMS matrix. The CI particles and the PDMS were mixed at different weight ratios and tested to determine the influence of CI concentration. The magnetic and mechanical properties of the magnetic elastomers were characterized, respectively, by vibrating-sample magnetometer and by tensile testing using a mechanical analyzer. The elastomer was found to exhibit high magnetization and good mechanical flexibility. The morphology and deformation of the CI-PDMS membrane also were observed. A magnetically actuated microfluidic mixer (that is, a micromixer) integrated with CI-PDMS elastomer membranes was successfully designed and fabricated. The high efficiency and quality of the mixing makes possible the impressive potential applications of this unique CI-PDMS material in microfluidic systems. © Springer-Verlag 2010.

  9. Analysis of protein carbonylation - pitfalls and promise in commonly used methods

    DEFF Research Database (Denmark)

    Rogowska-Wrzesinska, A.; Wojdyla, K.; Nedic, O.

    2014-01-01

    that research scientists are becoming more eager to be able to measure accurately the level of oxidized protein in biological materials, and to determine the precise site of the oxidative attack on the protein, in order to get insights into the molecular mechanisms involved in the progression of diseases....... Several methods for measuring protein carbonylation have been implemented in different laboratories around the world. However, to date no methods prevail as the most accurate, reliable, and robust. The present paper aims at giving an overview of the common methods used to determine protein carbonylation...... in biological material as well as to highlight the limitations and the potential. The ultimate goal is to give quick tips for a rapid decision making when a method has to be selected and taking into consideration the advantage and drawback of the methods....

  10. Analysis of protein carbonylation-pitfalls and promise in commonly used methods

    DEFF Research Database (Denmark)

    Rogowska-Wrzesinska, Adelina; Wojdyla, K; Nedić, O

    2014-01-01

    that research scientists are becoming more eager to be able to measure accurately the level of oxidized protein in biological materials, and to determine the precise site of the oxidative attack on the protein, in order to get insights into the molecular mechanisms involved in the progression of diseases....... Several methods for measuring protein carbonylation have been implemented in different laboratories around the world. However, to date no methods prevail as the most accurate, reliable, and robust. The present paper aims at giving an overview of the common methods used to determine protein carbonylation...... in biological material as well as to highlight the limitations and the potential. The ultimate goal is to give quick tips for a rapid decision making when a method has to be selected and taking into consideration the advantage and drawback of the methods....

  11. Dual-band microwave absorption properties of metamaterial absorber composed of split ring resonator on carbonyl iron powder composites

    Science.gov (United States)

    Lim, Jun-Hee; Ryu, Yo-Han; Kim, Sung-Soo

    2015-05-01

    This study investigated the dual-band absorption properties of metamaterial absorbers composed of a split ring resonator (SRR) on a grounded magnetic substrate. Polymer composites of carbonyl iron powders (CIP) of high permeability and magnetic loss were used as the substrate material. Computational tools were used to model the interaction between electromagnetic waves and materials with the SRR structure. For perpendicular polarization with an electric field (E) perpendicular to the SRR gap, dualband absorption peaks are predicted in the simulation result of reflection loss. Magnetic resonance resulting from antiparallel currents between the SRR and the ground plane is observed at the frequencies of two absorption peaks. The first strong absorption peak at the lower frequency (3.3 GHz) is due to magnetic resonance at the wire part of the SRR. The second absorption peak at the higher frequency (7.2 GHz) is due to magnetic resonance at the SRR split gap. The decreased capacitance with increased gap spacing moves the second absorption frequency to higher frequencies, while the first absorption peak is invariant with gap spacing. In the case of dual gaps at the opposite sides of the SRR, a single absorption peak is predicted due to the elimination of low-frequency resonance. For parallel polarization with the E-field parallel to the SRR gap, a single absorption peak is predicted, corresponding to magnetic resonance at the SRR wire.[Figure not available: see fulltext.

  12. Carbonylative Heck Reactions Using CO Generated ex Situ in a Two-Chamber System

    DEFF Research Database (Denmark)

    Hermange, Philippe; Gøgsig, Thomas; Lindhardt, Anders Thyboe

    2011-01-01

    A carbonylative Heck reaction of aryl iodides and styrene derivatives employing a two-chamber system using a stable, crystalline, and nontransition metal based carbon monoxide source is reported. By applying near-stoichiometric amounts of the carbon monoxide precursor, an effective exploitation o...... of the hazardous CO gas is obtained affording chalcone derivatives in good yields. Application to isotope labeling, incorporating 13CO, was further established....

  13. The magnetorheological fluid of carbonyl iron suspension blended with grafted MWCNT or graphene

    Science.gov (United States)

    Rwei, Syang-Peng; Ranganathan, Palraj; Chiang, Whe-Yi; Wang, Tza-Yi

    2017-12-01

    In this work, the magnetorheological (MR) fluids containing MWCNT/CI (carbonyl iron) complex and graphene/CI complex were prepared and have the better dispersity in silicone oil than CI powders alone. 1, 4-Aminobenzoic acid (PABA) was used as a grafting agent to modify CI powders to have NH2-end-group so that such nanoparticles can adsorb to acid-treated MWCNT or graphene via attraction of NH2 and COOH groups. The MWCNT/CI complex and graphene/CI complex have a structure of carbonyl iron nanoparticles adsorbed to MWCNT and graphene by self assembly, respectively. Because the carbonyl iron particles possessing magnetic permeability in nanometer scale adsorb to MWCNT or graphene which usually has a nanometer-scaled diameter and a micrometer-scaled length in this work, the dispersity of MWCNT/CI or graphene/CI complex in silicone oil is superior than the previous report [15] that the micrometer-scaled carbonyl iron microspheres were coated with multiwalled carbon nanotubes. Among CI (unmodified), MWCNT/CI and graphene/CI, graphene/CI has the best dispersity while MWCNT/CI still has the better dispersity than unmodified CI. At the temperature T = 300 K, the saturation magnetizations of CI, MWCNT/CI, graphene/CI are 208, 211 emu/g, and 204 emu/g, respectively, indicating that MWCNT/CI complex and graphene/CI complex still maintain the saturation magnetization as high as CI without being interfered by the blended MWCNT or graphene. A wide dynamic range of the yield stress adjusted through varying the electric current can be achieved by the MR fluids containing 69 wt% MWCNT/CI and graphene/CI which is useful in a shock absorber or damper. The result of the yield stress indicates the suspended MWCNT/CI particles are oriented more easily toward the direction perpendicular to the flow direction to block the flow stream lines.

  14. An intercomparison of aircraft instrumentation for tropospheric measurements of carbonyl sulfide, hydrogen sulfide, and carbon disulfide

    OpenAIRE

    Gregory, Gerald L; Douglas D. Davis; Thornton, Donald C; James E. Johnson; Bandy, Alan R.; Saltzman, Eric S.; Andreae, Meinrat O.; Barrick, John D

    1993-01-01

    This paper reports results of NASA's Chemical Instrumentation and Test Evaluation (CITE 3) during which airborne measurements for carbonyl sulfide (COS), hydrogen sulfide (H2S), and carbon disulfide (CS2) were intercompared. Instrumentation included a gas chromatograph using flame photometric detection (COS, H2S, and CS2), a gas chromatograph using mass spectrometric detection (COS and CS2), a gas chromatograph using fluorination and subsequent SF6 detection via electron capture (COS and CS2)...

  15. Identification of carbonylated lipids from different phospholipid classes by shotgun and LC-MS lipidomics.

    Science.gov (United States)

    Ni, Zhixu; Milic, Ivana; Fedorova, Maria

    2015-07-01

    Oxidized lipids play a significant role in the pathogenesis of numerous oxidative stress-related human disorders, such as atherosclerosis, obesity, inflammation, and autoimmune diseases. Lipid peroxidation, induced by reactive oxygen and nitrogen species, yields a high variety of modified lipids. Among them, carbonylated lipid peroxidation products (oxoLPP), formed by oxidation of the fatty acid moiety yielding aldehydes or ketones (carbonyl groups), are electrophilic compounds that are able to modify nucleophilic substrates like proteins, nucleic acid, and aminophospholipids. Some carbonylated phosphatidylcholines possess even pro-inflammatory activities. However, little is known about oxoLPP derived from other phospholipid (PL) classes. Here, we present a new analytical strategy based on the mass spectrometry (MS) of PL-oxoLPP derivatized with 7-(diethylamino)coumarin-3-carbohydrazide (CHH). Shotgun MS revealed many oxoLPP derived from in vitro oxidized glycerophosphatidylglycerols (PG, 31), glycerophosphatidylcholine (PC, 23), glycerophosphatidylethanolamine (PE, 34), glycerophosphatidylserines (PS, 7), glycerophosphatidic acids (PA, 17), and phosphatidylinositiolphosphates (PIP, 6) vesicles. This data were used to optimize LipidXplorer-assisted identification, and a python-based post-processing script was developed to increase both throughput and accuracy. When applied to full lipid extracts from rat primary cardiomyocytes treated with peroxynitrite donor SIN-1, ten PL-bound oxoLPP were unambiguously identified by LC-MS, including two PC-, two PE-, one PG-, two PS-, and three PA-derived species. Some of the well-known carbonylated PC were detected, while most PL-oxoLPP were shown for the first time.

  16. First-row transition metal catalyzed reduction of carbonyl functionalities: a mechanistic perspective.

    Science.gov (United States)

    Chakraborty, Sumit; Guan, Hairong

    2010-08-28

    The use of first-row transition metals for the catalytic reduction of carbonyl functionalities has become increasingly important in homogeneous catalysis. This Perspective examines the mechanistic aspects of these reduction reactions, with a focus on various interactions between metal complexes and substrates. Four different types of catalytic pathways, namely catalysis with dihydride (or dihydrogen) complexes, catalysis with monohydride complexes, metal-ligand bifunctional catalysis, and catalysis involving ionic mechanisms, are discussed with recent examples highlighted.

  17. Bifunctional ligands in combination with phosphines and Lewis acidic phosphonium [corrected] for the carbonylative Sonogashira reaction.

    Science.gov (United States)

    Tan, Chen; Wang, Peng; Liu, Huan; Zhao, Xiao-Li; Lu, Yong; Liu, Ye

    2015-07-11

    The combination of phosphine-ligated Pd catalysis and phosphonium(V) [corrected] Lewis acid catalysis has been developed for the carbonylative Sonogashira reaction using phosphino-phosphonium [corrected] salts (L1-L4) as bifunctional ligands, in which the Lewis acidic phosphonium(V) [corrected] cations can form secondary bonds with O atoms (in C=O) to cooperatively stabilize Pd-acyl intermediates.

  18. The interaction of metal carbonyl compounds with organic polymers and monomers

    OpenAIRE

    Lyons, Michael P.

    1993-01-01

    The photochemistry of W(CO)6, Mo(CO)6, and Cr(CO)6 in the presence of monomeric and polymeric triphenylphosphine ligands was investigated in toluene solution, using laser flash photolysis with 355nm excitation. The mechanism and kinetics of interaction of the primary photoproducts M(CO)5(toluene) (M = W, Mo, or Cr) with the various monomeric ligands were investigated. Interaction of the metal carbonyl photofragments with various homopolymers is also discussed. The polymerisation methods used ...

  19. Rhodium-Catalyzed Asymmetric Hydrogenation of α,β-Unsaturated Carbonyl Compounds via Thiourea Hydrogen Bonding.

    Science.gov (United States)

    Wen, Jialin; Jiang, Jun; Zhang, Xumu

    2016-09-16

    The strategy of secondary interaction enables enantioselectivity for homogeneous hydrogenation. By introducing hydrogen bonding of substrates with thiourea from the ligand, α,β-unsaturated carbonyl compounds, such as amides and esters, are hydrogenated with high enantiomeric excess. The substrate scope for this chemical transformation is broad with various substituents at the β-position. Control experiments revealed that each unit of the ligand ZhaoPhos is irreplaceable. No nonlinear effect was observed for this Rh/ZhaoPhos-catalyzed asymmetric hydrogenation.

  20. Novel Carbonyl Analogs of Tamoxifen: Design, Synthesis, and Biological Evaluation

    Directory of Open Access Journals (Sweden)

    Konstantinos M. Kasiotis

    2017-09-01

    Full Text Available Aim of this work was to provide tamoxifen analogs with enhanced estrogen receptor (ER binding affinity. Hence, several derivatives were prepared using an efficient triarylethylenes synthetic protocol. The novel compounds bioactivity was evaluated through the determination of their receptor binding affinity and their agonist/antagonist activity against breast cancer tissue using a MCF-7 cell-based assay. Phenyl esters 6a,b and 8a,b exhibited binding affinity to both ERα and ERβ higher than 4-hydroxytamoxifen while compounds 13 and 14 have shown cellular antiestrogenic activity similar to 4-hydroxytamoxifen and the known ER inhibitor ICI182,780. Theoretical calculations and molecular modeling were applied to investigate, support and explain the biological profile of the new compounds. The relevant data indicated an agreement between calculations and demonstrated biological activity allowing to extract useful structure-activity relationships. Results herein underline that modifications of tamoxifen structure still provide molecules with substantial activity, as portrayed in the inhibition of MCF-7 cells proliferation.

  1. Novel Carbonyl Analogues of Tamoxifen: Design, Synthesis, and Biological Evaluation

    Science.gov (United States)

    Kasiotis, Konstantinos M.; Lambrinidis, George; Fokialakis, Nikolas; Tzanetou, Evangelia N.; Mikros, Emmanuel; Haroutounian, Serkos A.

    2017-09-01

    Aim of this work was to provide tamoxifen analogues with enhanced estrogen receptor binding affinity. Hence, several derivatives were prepared using an efficient triarylethylenes synthetic protocol. The novel compounds bioactivity was evaluated through the determination of their receptor binding affinity and their agonist/antagonist activity against breast cancer tissue using a MCF-7 cell-based assay. Phenyl esters 6a,b and 8a,b exhibited binding affinity to both ERα and ERβ higher than 4-hydroxytamoxifen while compounds 13 and 14 have shown cellular antiestrogenic activity similar to 4-hydroxytamoxifen and the known estrogen receptor inhibitor ICI182,780. Theoretical calculations and molecular modelling were applied to investigate, support and explain the biological profile of the new compounds. The relevant data indicated an agreement between calculations and demonstrated biological activity allowing to extract useful structure-activity relationships. Results herein underline that modifications of tamoxifen structure still provide molecules with substantial activity, as portrayed in the inhibition of MCF-7 cells proliferation.

  2. Oxidative and carbonyl stress in pregnant women with obstructive sleep apnea.

    Science.gov (United States)

    Khan, Nazia; Lambert-Messerlian, Geralyn; Monteiro, Joao Filipe; Hodosy, Julius; Tóthová, Ľubomíra; Celec, Peter; Eklund, Elizabeth; Curran, Patrizia; Bourjeily, Ghada

    2017-02-24

    Pregnant women are particularly susceptible to sleep-disordered breathing. Obstructive sleep apnea (OSA) in pregnancy is associated with poor pregnancy and fetal outcomes. Oxidative stress caused by intermittent hypoxemia and reoxygenation may impact pregnancy health. We hypothesize that pregnant women with OSA have a pronounced oxidative stress profile. A case-control study was performed to study oxidative stress markers in the serum of pregnant women with or without OSA. Patients with OSA were identified between 2003 and 2009. Contemporaneous controls were pregnant subjects without apnea, gasping, or snoring around the time of delivery. Serum markers of oxidative and carbonyl stress were measured by spectrophotometric/fluorometric methods. Multiple linear regression analysis was used with a model including age, body mass index at delivery, history of diabetes, and gestational age. Serum samples from 23 OSA cases and 41 controls were identified. Advanced oxidation protein products, a marker for oxidative stress, and advanced glycation end products (AGEs), a marker for carbonyl stress, were significantly lower in women with OSA than in controls (p value oxidative and carbonyl stress markers compared to controls, suggesting a possible protective effect of intermittent hypoxia. Whether OSA in pregnancy impacts oxidative stress differently than OSA in the general population remains to be confirmed.

  3. Synthesis and Characterization of Group-6 Metal Carbonyl Complexes of Aroyl Hydrazone Derivatives

    Directory of Open Access Journals (Sweden)

    Mohd Saleem

    2012-01-01

    Full Text Available Carbonyl complexes of Chromium, molybdenum and tungsten of composition, [M(CO4L-L], (where M= Cr, Mo or W and L-L= benzoic acid[1-(Furan-2-ylmethylene]hydrazide (BFMH, benzoic acid[(thiophene-2-ylmethylene]hydrazide (BTMH, benzoic acid[1-(thiophene-2-ylethylidene] hydrazide (BTEH, benzoic acid (phenylmethylenehydrazide (BPMH and benzoic acid[1-(anisol-3-ylmethylene] hydrazide (BAMH are reported. These have been prepared by refluxing metal carbonyls and the ligands in 1:1molar ratio. The complexes were characterized by elemental analysis, IR spectra, UV-vis spectra, 1H NMR, TGA/DTA, conductivity and magnetic susceptibility measurements. The IR bands suggest that in all the complexes the ligands behave as neutral bidentate chelating type coordinating metal through carbonyl oxygen and azomethine nitrogen. The CO force constants and CO-CO interaction constants for these derivatives have been calculated using Cotton-Kraihanzel secular equations, which indicate poor π-bonding ability of the coordinated ligands.

  4. Incorporating conjugated carbonyl compounds into carbon nanomaterials as electrode materials for electrochemical energy storage.

    Science.gov (United States)

    Yang, Guanhui; Zhang, Yu; Huang, Yanshan; Shakir, Muhammad Imran; Xu, Yuxi

    2016-11-23

    The increasing demand for energy and growing concerns for environmental issues are promoting the development of organic electrode materials. Among these, conjugated carbonyl compounds (CCCs) represent one of the most attractive and promising candidates for sustainable and eco-benign energy storage devices in the coming future. However, most of the current compounds suffer from dissolution in organic electrolytes and low electronic conductivity, which result in severe capacity decay and poor rate performance. Recently, researchers have achieved considerable progress by introducing electroactive carbonyl compounds into carbon nanomaterials. This perspective provides an overview of the up-to-date development of these nanocomposites in metal ion batteries (lithium-ion batteries or sodium-ion batteries) and supercapacitors (SCs), including the synthesis, performance improvement and applications. We mainly focus on carbon nanotubes (CNTs), graphene and mesoporous carbon (MC) as carbon nanomaterials because of their high specific surface area, good conductivity, electrochemical stability and favourable interaction with conjugated carbonyl compounds. This strategy opens up new possibilities to realize cost-effective, sustainable and versatile energy storage devices.

  5. Protein carbonyls are acutely elevated following single set anaerobic exercise in resistance trained men.

    Science.gov (United States)

    Bloomer, Richard J; Fry, Andrew C; Falvo, Michael J; Moore, Christopher A

    2007-12-01

    The purpose of this investigation was to determine if a single set of strenuous squat exercise would result in an acute oxidative stress, as demonstrated previously by a single sprint. Thirteen resistance trained men performed one set of 15 repetitions of barbell squats using 70% of one repetition maximum and a 30 s maximal cycle sprint on two different occasions. The total work performed was calculated for each exercise bout. Heart rate, perceived exertion, blood lactate, protein carbonyls, 8-hydroxydeoxyguanosine, and malondialdehyde were measured before and within 1 min following exercise. No differences were noted between the squat and sprint tests for total work, heart rate or perceived exertion. An exercise test by time interaction was evident for blood lactate with values greater following sprinting compared to squatting (P=0.0005). Postexercise protein carbonyls were not different between exercise tests but were elevated above rest (P=0.04) by 111% and 74% following sprinting and squatting, respectively, while 8-hydroxydeoxyguanosine and malondialdehyde were relatively unaffected by either exercise test. These data indicate that a single bout of strenuous squatting and sprinting performed by resistance trained men results in elevated protein carbonyls, while having little impact on 8-hydroxydeoxyguanosine or malondialdehyde during the immediate postexercise period.

  6. Role of Protein Carbonylation in Skeletal Muscle Mass Loss Associated with Chronic Conditions

    Directory of Open Access Journals (Sweden)

    Esther Barreiro

    2016-05-01

    Full Text Available Muscle dysfunction, characterized by a reductive remodeling of muscle fibers, is a common systemic manifestation in highly prevalent conditions such as chronic heart failure (CHF, chronic obstructive pulmonary disease (COPD, cancer cachexia, and critically ill patients. Skeletal muscle dysfunction and impaired muscle mass may predict morbidity and mortality in patients with chronic diseases, regardless of the underlying condition. High levels of oxidants may alter function and structure of key cellular molecules such as proteins, DNA, and lipids, leading to cellular injury and death. Protein oxidation including protein carbonylation was demonstrated to modify enzyme activity and DNA binding of transcription factors, while also rendering proteins more prone to proteolytic degradation. Given the relevance of protein oxidation in the pathophysiology of many chronic conditions and their comorbidities, the current review focuses on the analysis of different studies in which the biological and clinical significance of the modifications induced by reactive carbonyls on proteins have been explored so far in skeletal muscles of patients and animal models of chronic conditions such as COPD, disuse muscle atrophy, cancer cachexia, sepsis, and physiological aging. Future research will elucidate the specific impact and sites of reactive carbonyls on muscle protein content and function in human conditions.

  7. A new structural arrangement in proteins involving lysine NH3+ group and carbonyl.

    Science.gov (United States)

    Rogacheva, Olga N; Izmailov, Sergei A; Slipchenko, Lyudmila V; Skrynnikov, Nikolai R

    2017-11-27

    Screening of the Protein Data Bank led to identification of a recurring structural motif where lysine NH3+ group interacts with backbone carbonyl. This interaction is characterized by linear atom arrangement, with carbonyl O atom positioned on the three-fold symmetry axis of the NH3+ group (angle Cε-Nζ-O close to 180°, distance Nζ-O ca. 2.7-3.0 Å). Typically, this linear arrangement coexists with three regular hydrogen bonds formed by lysine NH3+ group (angle Cε-Nζ-acceptor atom close to 109°, distance Nζ-acceptor atom ca. 2.7-3.0 Å). Our DFT calculations using polarizable continuum environment suggest that this newly identified linear interaction makes an appreciable contribution to protein's energy balance, up to 2 kcal/mol. In the context of protein structure, linear interactions play a role in capping the C-termini of α-helices and 310-helices. Of note, linear interaction involving conserved lysine is consistently found in the P-loop of numerous NTPase domains, where it stabilizes the substrate-binding conformation of the P-loop. Linear interaction NH3+ - carbonyl represents an interesting example of ion-dipole interactions that has so far received little attention compared to ion-ion interactions (salt bridges) and dipole-dipole interactions (hydrogen bonds), but nevertheless represents a distinctive element of protein architecture.

  8. Ultrafast carbonyl motion of the photoactive yellow protein chromophore probed by femtosecond circular dichroism.

    Science.gov (United States)

    Mendonça, Lucille; Hache, François; Changenet-Barret, Pascale; Plaza, Pascal; Chosrowjan, Haik; Taniguchi, Seiji; Imamoto, Yasushi

    2013-10-02

    Motions of the trans-p-coumaric acid carbonyl group following the photoexcitation of the R52Q mutant of photoactive yellow protein (PYP) are investigated, for the first time, by ultrafast time-resolved circular dichroism (TRCD) spectroscopy. TRCD is monitored in the near-ultraviolet, over a time scale of 10 ps. Immediately after excitation, TRCD is found to exhibit a large negative peak, which decays within a few picoseconds. A quantitative analysis of the signals shows that, upon excitation, the carbonyl group undergoes a fast (≪0.8 ps) and unidirectional flipping motion in the excited state with an angle of ca. 17-53°. For the subset of proteins that do not enter the signaling photocycle, TRCD provides strong evidence that the carbonyl group moves back to its initial position, leading to the formation of a nonreactive ground-state intermediate of trans conformation. The initial ground state is then restored within ca. 3 ps. Comparative study of R52Q and wild-type PYP provides direct evidence that the absence of Arg52 has no effect on the conformational changes of the chromophore during those steps.

  9. Profiling Carbonylated Proteins in Heart and Skeletal Muscle Mitochondria from Trained and Untrained Mice.

    Science.gov (United States)

    Carpentieri, Andrea; Gamberi, Tania; Modesti, Alessandra; Amoresano, Angela; Colombini, Barbara; Nocella, Marta; Bagni, Maria Angela; Fiaschi, Tania; Barolo, Lorenzo; Gulisano, Massimo; Magherini, Francesca

    2016-10-07

    Understanding the relationship between physical exercise, reactive oxygen species, and skeletal muscle modification is important in order to better identify the benefits or the damages that appropriate or inappropriate exercise can induce. Heart and skeletal muscles have a high density of mitochondria with robust energetic demands, and mitochondria plasticity has an important role in both the cardiovascular system and skeletal muscle responses. The aim of this study was to investigate the influence of regular physical activity on the oxidation profiles of mitochondrial proteins from heart and tibialis anterior muscles. To this end, we used the mouse as animal model. Mice were divided into two groups: untrained and regularly trained. The carbonylated protein pattern was studied by two-dimensional gel electrophoresis followed by Western blot with anti-dinitrophenyl hydrazone antibodies. Mass spectrometry analysis allowed the identification of several different protein oxidation sites, including methionine, cysteine, proline, and leucine residues. A large number of oxidized proteins were found in both untrained and trained animals. Moreover, mitochondria from skeletal muscles and heart showed almost the same carbonylation pattern. Interestingly, exercise training seems to increase the carbonylation level mainly of mitochondrial proteins from skeletal muscle.

  10. Yttrium (III chloride catalyzed Mannich reaction: An efficient procedure for the synthesis of β-amino carbonyl compounds

    Directory of Open Access Journals (Sweden)

    Venkateswarlu Yekkirala

    2014-12-01

    Full Text Available Yttrium (III chloride catalyzed Mannich reaction of aldehydes with ketones and amines in acetonitrile at reflux temperature to give various β-amino carbonyl compounds in very good yields.

  11. Higher Education.

    Science.gov (United States)

    Hendrickson, Robert M.

    This chapter reviews litigation in higher education for 1986. The first section discusses the relationship between postsecondary institutions and various governmental agencies, in which litigation covers questions on the authority of boards, access to information through sunshine laws, questions of tax exempt status, and issues of accreditation.…

  12. Human microsomal carbonyl reducing enzymes in the metabolism of xenobiotics: well-known and promising members of the SDR superfamily.

    Science.gov (United States)

    Skarydová, Lucie; Wsól, Vladimír

    2012-05-01

    The best known, most widely studied enzyme system in phase I biotransformation is cytochrome P450 (CYP), which participates in the metabolism of roughly 9 of 10 drugs in use today. The main biotransformation isoforms of CYP are associated with the membrane of the endoplasmatic reticulum (ER). Other enzymes that are also active in phase I biotransformation are carbonyl reducing enzymes. Much is known about the role of cytosolic forms of carbonyl reducing enzymes in the metabolism of xenobiotics, but their microsomal forms have been mostly poorly studied. The only well-known microsomal carbonyl reducing enzyme taking part in the biotransformation of xenobiotics is 11β-hydroxysteroid dehydrogenase 1, a member of the short-chain dehydrogenase/reductase superfamily. Physiological roles of microsomal carbonyl reducing enzymes are better known than their participation in the metabolism of xenobiotics. This review is a summary of the fragmentary information known about the roles of the microsomal forms. Besides 11β-hydroxysteroid dehydrogenase 1, it has been reported, so far, that retinol dehydrogenase 12 participates only in the detoxification of unsaturated aldehydes formed upon oxidative stress. Another promising group of microsomal biotransformation carbonyl reducing enzymes are some members of 17β-hydroxysteroid dehydrogenases. Generally, it is clear that this area is, overall, quite unexplored, but carbonyl reducing enzymes located in the ER have proven very interesting. The study of these enzymes could shed new light on the metabolism of several clinically used drugs or they could become an important target in connection with some diseases.

  13. Antiatherogenic effect of bisvanillyl-hydralazone, a new hydralazine derivative with antioxidant, carbonyl scavenger, and antiapoptotic properties.

    Science.gov (United States)

    Bouguerne, Benaissa; Belkheiri, Nadji; Bedos-Belval, Florence; Vindis, Cécile; Uchida, Koji; Duran, Hubert; Grazide, Marie-Hélène; Baltas, Michel; Salvayre, Robert; Nègre-Salvayre, Anne

    2011-06-01

    Reactive oxygen species (ROS) generated within the vascular wall trigger low-density lipoprotein (LDL) oxidation, lipid peroxidation, and carbonyl stress that are involved in atherogenesis. We recently reported that the antihypertensive drug, hydralazine, exhibits carbonyl scavenger and antiatherogenic properties, but only moderate antioxidant activity, so that high concentrations are required for inhibiting LDL oxidation. We aimed to develop agents sharing both antioxidant and carbonyl scavenger properties. We have synthesized a new hydralazine derivative, the bisvanillyl-hydralazone (BVH). BVH strongly inhibited LDL oxidation induced by copper and by human endothelial cells (HMEC-1), and prevented the formation of macrophagic foam cells. BVH reduced both the extracellular generation of ROS (superoxide anion and hydrogen peroxide) induced by oxidized LDL (oxLDL), as well as intracellular oxidative stress and proteasome activation, NFkappaB activation, and oxLDL-mediated proinflammatory signaling. In parallel, BVH prevented the carbonyl stress induced by oxLDL on cellular proteins, and blocked the apoptotic cascade as assessed by the inhibition of Bid cleavage, cytochrome C release, and DEVDase activation. Lastly, BVH prevented atherogenesis and carbonyl stress in apoE(-/-) mice. In conclusion, BVH is the prototype of a new class of antioxidant and carbonyl scavenger agents designed for new therapeutical approaches in atherosclerosis.

  14. Enhancement effects of ultrasound assisted in the synthesis of NiAl hydrotalcite for carbonyl sulfide removal.

    Science.gov (United States)

    Zhao, Shunzheng; Yi, Honghong; Tang, Xiaolong; Gao, Fengyu; Yu, Qingjun; Zhou, Yuansong; Wang, Jiangen; Huang, Yonghai; Yang, Zhongyu

    2016-09-01

    Ultrasonic effect in the synthesis of catalysts of NiAl oxides prepared starting from the coprecipitation method of a hydrotalcite structure was evaluated in this work. Removal of carbonyl sulfide (COS) at low temperature over the hydrotalcite-derived oxides was studied. The samples were characterized by X-ray Diffraction (XRD), scanning electron microscope (SEM), N2 adsorption/desorption techniques, Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and CO2 temperature-programmed desorption (TPD). It is found that hydrotalcite treated with ultrasonic has smaller average crystallite size and higher particle dispersion compared to hydrotalcite without ultrasonic treatment. As a result, mixed oxides derived from hydrotalcite treated with ultrasonic show more developed pore structure which is good for the physical adsorption of gaseous pollutant. The result of desulfuration test showed that removal efficiency of COS on the NiAl mixed oxides prepared by ultrasonic method (30min) is greater than that on the catalyst prepared without the ultrasonic irradiation assistance with the same aging time. One important reason for the high activity is that when the ultrasonic is used the number of weak basic sites (OH(-) groups) and moderate basic sites (M-O) was increased, whereas the number of strong basic sites (O(2-)) was decreased. Therefore, ultrasonic treatment promoted the COS hydrolysis and suppress the poisoning of the catalyst. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Lipid Peroxide-Derived Short-Chain Carbonyls Mediate Hydrogen Peroxide-Induced and Salt-Induced Programmed Cell Death in Plants1[OPEN

    Science.gov (United States)

    Biswas, Md. Sanaullah; Mano, Jun’ichi

    2015-01-01

    Lipid peroxide-derived toxic carbonyl compounds (oxylipin carbonyls), produced downstream of reactive oxygen species (ROS), were recently revealed to mediate abiotic stress-induced damage of plants. Here, we investigated how oxylipin carbonyls cause cell death. When tobacco (Nicotiana tabacum) Bright Yellow-2 (BY-2) cells were exposed to hydrogen peroxide, several species of short-chain oxylipin carbonyls [i.e. 4-hydroxy-(E)-2-nonenal and acrolein] accumulated and the cells underwent programmed cell death (PCD), as judged based on DNA fragmentation, an increase in terminal deoxynucleotidyl transferase dUTP nick end labeling-positive nuclei, and cytoplasm retraction. These oxylipin carbonyls caused PCD in BY-2 cells and roots of tobacco and Arabidopsis (Arabidopsis thaliana). To test the possibility that oxylipin carbonyls mediate an oxidative signal to cause PCD, we performed pharmacological and genetic experiments. Carnosine and hydralazine, having distinct chemistry for scavenging carbonyls, significantly suppressed the increase in oxylipin carbonyls and blocked PCD in BY-2 cells and Arabidopsis roots, but they did not affect the levels of ROS and lipid peroxides. A transgenic tobacco line that overproduces 2-alkenal reductase, an Arabidopsis enzyme to detoxify α,β-unsaturated carbonyls, suffered less PCD in root epidermis after hydrogen peroxide or salt treatment than did the wild type, whereas the ROS level increases due to the stress treatments were not different between the lines. From these results, we conclude that oxylipin carbonyls are involved in the PCD process in oxidatively stressed cells. Our comparison of the ability of distinct carbonyls to induce PCD in BY-2 cells revealed that acrolein and 4-hydroxy-(E)-2-nonenal are the most potent carbonyls. The physiological relevance and possible mechanisms of the carbonyl-induced PCD are discussed. PMID:26025050

  16. The Drosophila carbonyl reductase sniffer is an efficient 4-oxonon-2-enal (4ONE) reductase.

    Science.gov (United States)

    Martin, Hans-Jörg; Ziemba, Marta; Kisiela, Michael; Botella, José A; Schneuwly, Stephan; Maser, Edmund

    2011-05-30

    Studies with the fruit-fly Drosophila melanogaster demonstrated that the enzyme sniffer prevented oxidative stress-induced neurodegeneration. Mutant flies overexpressing sniffer had significantly extended life spans in a 99.5% oxygen atmosphere compared to wild-type flies. However, the molecular mechanism of this protection remained unclear. Sequence analysis and database searches identified sniffer as a member of the short-chain dehydrogenase/reductase superfamily with a 27.4% identity to the human enzyme carbonyl reductase type I (CBR1). As CBR1 catalyzes the reduction of the lipid peroxidation products 4HNE and 4ONE, we tested whether sniffer is able to metabolize these lipid derived aldehydes by carbonyl reduction. To produce recombinant enzyme, the coding sequence of sniffer was amplified from a cDNA-library, cloned into a bacterial expression vector and the His-tagged protein was purified by Ni-chelate chromatography. We found that sniffer catalyzed the NADPH-dependent carbonyl reduction of 4ONE (K(m)=24±2 μM, k(cat)=500±10 min(-1), k(cat)/K(m)=350 s(-1) mM(-1)) but not that of 4HNE. The reaction product of 4ONE reduction by sniffer was mainly 4HNE as shown by HPLC- and GC/MS analysis. Since 4HNE, though still a potent electrophile, is less neurotoxic and protein reactive than 4ONE, one mechanism by which sniffer exerts its neuroprotective effects in Drosophila after oxidative stress may be enzymatic reduction of 4ONE. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  17. Determination of carbonyl compounds in air by HPLC; Determinacion de compuestos carbonilicos en aire por HPLC

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, S.; Perez, R.M.; Campos, A.; Gonzalez, D.

    1995-07-01

    A method for the determination of seven carbonyl compounds in air is presented. The procedure involve sampling of air by a Sep-Pak Cartridge impregnated with 2,4-dinitrophenylhydrazine. Elution was done with 3 mL of acetonitrile and the eluate was diluted to 5 mL. The analysis was done by HPLC with UV detection and external standard method quantification. It has been achieved relative standard deviations about 5% and detection limits of 80 ng/cartridge for formaldehyde, acetaldehyde and acetoacetonitrile. Three different types of samples (rural, urban, petrol emission) were successfully analyzed. (Author) 12 refs.

  18. Non-enzymatic modification of aminophospholipids by carbonyl-amine reactions.

    Science.gov (United States)

    Naudí, Alba; Jové, Mariona; Ayala, Victòria; Cabré, Rosanna; Portero-Otín, Manuel; Pamplona, Reinald

    2013-02-05

    Non-enzymatic modification of aminophospholipids by lipid peroxidation-derived aldehydes and reducing sugars through carbonyl-amine reactions are thought to contribute to the age-related deterioration of cellular membranes and to the pathogenesis of diabetic complications. Much evidence demonstrates the modification of aminophospholipids by glycation, glycoxidation and lipoxidation reactions. Therefore, a number of early and advanced Maillard reaction-lipid products have been detected and quantified in different biological membranes. These modifications may be accumulated during aging and diabetes, introducing changes in cell membrane physico-chemical and biological properties.

  19. A Device-Independent Evaluation of Carbonyl Emissions from Heated Electronic Cigarette Solvents.

    Directory of Open Access Journals (Sweden)

    Ping Wang

    Full Text Available To investigate how the two main electronic (e- cigarette solvents-propylene glycol (PG and glycerol (GL-modulate the formation of toxic volatile carbonyl compounds under precisely controlled temperatures in the absence of nicotine and flavor additives.PG, GL, PG:GL = 1:1 (wt/wt mixture, and two commercial e-cigarette liquids were vaporized in a stainless steel, tubular reactor in flowing air ranging up to 318°C to simulate e-cigarette vaping. Aerosols were collected and analyzed to quantify the amount of volatile carbonyls produced with each of the five e-liquids.Significant amounts of formaldehyde and acetaldehyde were detected at reactor temperatures ≥215°C for both PG and GL. Acrolein was observed only in e-liquids containing GL when reactor temperatures exceeded 270°C. At 318°C, 2.03±0.80 μg of formaldehyde, 2.35±0.87 μg of acetaldehyde, and a trace amount of acetone were generated per milligram of PG; at the same temperature, 21.1±3.80 μg of formaldehyde, 2.40±0.99 μg of acetaldehyde, and 0.80±0.50 μg of acrolein were detected per milligram of GL.We developed a device-independent test method to investigate carbonyl emissions from different e-cigarette liquids under precisely controlled temperatures. PG and GL were identified to be the main sources of toxic carbonyl compounds from e-cigarette use. GL produced much more formaldehyde than PG. Besides formaldehyde and acetaldehyde, measurable amounts of acrolein were also detected at ≥270°C but only when GL was present in the e-liquid. At 215°C, the estimated daily exposure to formaldehyde from e-cigarettes, exceeded United States Environmental Protection Agency (USEPA and California Office of Environmental Health Hazard Assessment (OEHHA acceptable limits, which emphasized the need to further examine the potential cancer and non-cancer health risks associated with e-cigarette use.

  20. Mechanistic Investigations of the Iron(III)-Catalyzed Carbonyl-Olefin Metathesis Reaction.

    Science.gov (United States)

    Ludwig, Jacob R; Phan, Susan; McAtee, Christopher C; Zimmerman, Paul M; Devery, James J; Schindler, Corinna S

    2017-08-09

    Iron(III)-catalyzed carbonyl-olefin ring-closing metathesis represents a new approach toward the assembly of molecules traditionally generated by olefin-olefin metathesis or olefination. Herein, we report detailed synthetic, spectroscopic, kinetic, and computational studies to determine the mechanistic features imparted by iron(III), substrate, and temperature to the catalytic cycle. These data are consistent with an iron(III)-mediated asynchronous, concerted [2+2]-cycloaddition to form an intermediate oxetane as the turnover-limiting step. Fragmentation of the oxetane via Lewis acid-activation results in the formation of five- and six-membered unsaturated carbocycles.

  1. A green synthesis of α,β-unsaturated carbonyl compounds from glyceraldehyde acetonide

    Directory of Open Access Journals (Sweden)

    Cláudia O. Veloso

    2011-01-01

    Full Text Available The catalytic behavior of Cs-exchanged and Cs-impregnated zeolites (X and Y was studied using the Knoevenagel condensation between glyceraldehyde acetonide and ethyl acetoacetate in order to produce the corresponding α,β-unsaturated carbonyl compound that is an important intermediate for fine chemicals. The influence of reaction temperature, type of zeolite, and basicity of the sites on the catalytic behavior of the samples was evaluated. All zeolites were active for the studied reaction. The formation of the main condensation product was favored at lower reaction temperatures. Products of further condensations were also observed especially for samples that were only dried before catalytic test.

  2. Non-Enzymatic Modification of Aminophospholipids by Carbonyl-Amine Reactions

    Directory of Open Access Journals (Sweden)

    Reinald Pamplona

    2013-02-01

    Full Text Available Non-enzymatic modification of aminophospholipids by lipid peroxidation-derived aldehydes and reducing sugars through carbonyl-amine reactions are thought to contribute to the age-related deterioration of cellular membranes and to the pathogenesis of diabetic complications. Much evidence demonstrates the modification of aminophospholipids by glycation, glycoxidation and lipoxidation reactions. Therefore, a number of early and advanced Maillard reaction-lipid products have been detected and quantified in different biological membranes. These modifications may be accumulated during aging and diabetes, introducing changes in cell membrane physico-chemical and biological properties.

  3. Multiband microwave absorption films based on defective multiwalled carbon nanotubes added carbonyl iron/acrylic resin

    Energy Technology Data Exchange (ETDEWEB)

    Li Yong, E-mail: liyong1897@163.co [Institute of Naval Logistic Technology and Equipment of PLA, Beijing 100072 (China); Chen Changxin, E-mail: chen.c.x@sjtu.edu.c [National Key Laboratory of Nano/Micro Fabrication Technology, Key Laboratory for Thin Film and Microfabrication of the Ministry of Education, Research Institute of Micro/Nano Science and Technology, Shanghai Jiao Tong University, Shanghai 200240 (China); Pan Xiaoyan [School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China); Ni Yuwei; Zhang Song; Huang, Jie [Institute of Naval Logistic Technology and Equipment of PLA, Beijing 100072 (China); Chen Da; Zhang Yafei [National Key Laboratory of Nano/Micro Fabrication Technology, Key Laboratory for Thin Film and Microfabrication of the Ministry of Education, Research Institute of Micro/Nano Science and Technology, Shanghai Jiao Tong University, Shanghai 200240 (China)

    2009-05-01

    Defective multiwalled carbon nanotubes (MWCNTs) were introduced to the carbonyl iron (CI) based composites to improve its microwave absorption by a simple ultrasonic mixing process. The electromagnetic parameters were measured in the 2-18 GHz range. Microwave absorption of CI based composites with 2 mm in thickness was evidently enhanced by adding as little as 1.0 wt% defective MWCNTs with two well separated absorption peaks exceeding -20 dB, as compared with that of pure CI based and defective MWCNTs composites. The enhancement mechanism is thought due to the interaction and better electromagnetic match between defective MWCNTs and ferromagnetic CI particles.

  4. Sensitivity of Saccharomyces cerevisiae defective in TOR signaling pathway to carbonyl/oxidative stress

    Directory of Open Access Journals (Sweden)

    Valishkevych B. V.

    2014-09-01

    Full Text Available Aim. To investigate the influence of carbonyl/oxidative stress induced by glyoxal, methylglyoxal and hydrogen peroxide on the survival of Saccharomyces cerevisiae, defective for different parts of TOR- signaling pathway, grown on glucose or fructose. Methods. The assessment of number of colony-forming units to determine the yeast reproductive ability. Results. It was shown that at certain concentrations the mentioned above toxicants caused an increase in yeast survival, indicating the hormetic effect. Conclusions. The TOR signaling pathway is involved in the hormetic effect, but it is specific for each strain and depends on the type of carbohydrate in the incubation medium.

  5. Synthesis of [[sup 14]C]-N-[(trimethylamineboryl)carbonyl]-phenylalanine-methyl ester

    Energy Technology Data Exchange (ETDEWEB)

    Miller, M.C. III; Wyrick, S.D.; Hall, I.H. (North Carolina Univ., Chapel Hill, NC (United States). School of Pharmacy); Sood, A.; Spielvogel, B.F. (Boron Biologicals Inc., Raleigh, NC (United States))

    1992-08-01

    Reported is the synthesis of [[sup 14]C]-L-N-[(trimethylamine-boryl) carbonyl]-phenylalanine methyl ester, a boron containing [alpha]-amino acid dipeptide analog with antineoplastic, anti-inflammatory, and hypolipidemic activities. The [sup 14]C label is universally distributed among all carbon positions of the phenylalanine portion of the molecule. Briefly, the dipeptide is prepared by reacting the phenylalanine methyl ester hydrochloride salt with trimethylamine-carboxyborane, triphenylphospine (TPP), CCl[sub 4], and triethylamine (TEA) in acetonitrile, for 24 hours. The final product afforded a specific activity of 5.71 mCi/mmol. (author).

  6. Carbonylation of platelet proteins occurs as consequence of oxidative stress and thrombin activation, and is stimulated by ageing and type 2 diabetes.

    Science.gov (United States)

    Alexandru, Nicoleta; Constantin, Alina; Popov, Doina

    2008-01-01

    In normal ageing, as well as in diabetes mellitus, blood platelets are exposed to increasing amounts of reactive oxygen species. Because occurrence of carbonyl groups is the first step in oxidative damage of proteins, we questioned the formation of carbonylated proteins (i) in vitro: platelets exposed to oxidant hydrogen peroxide (H2O2) and agonist thrombin (in the presence/absence of antioxidants), and (ii) in vivo: during ageing progression, and in type 2 diabetes. Platelets were isolated from the blood of experimental animals (rats and hamsters) and humans (healthy, young and elderly), as well as from type 2 diabetics (matures and elderly). 2,4-Dinitrophenyl derivatization of the amino acid side chains was used to quantify protein carbonyls (spectrophotometry) and to immunodetect carbonylated protein bands (Western blotting). In animal models and humans, H2O2 produced dose-dependent increases in carbonylation of platelet proteins (vs. basal condition). Thrombin activation stimulated protein carbonyl formation in a process quenched by antioxidant catalase, suggesting that carbonylation was induced by the oxidative stress generated by activated platelets. Progression of ageing caused increased carbonylation of platelet proteins (vs. young age); enriched in carbonylated proteins, platelets of elderly subjects were less sensitive to H2O2. Type 2 diabetes additionally enhanced carbonylation of human platelet proteins (vs. the levels at young and elderly healthy subjects). In all experiments, protein carbonyl concentrations were correlated with changes in intensity of 2,4-dinitrophenyl-hydrazine-reactive protein bands on immunoblots. The results suggest that exogenous oxidative stress, thrombin activation, progression of ageing and type 2 diabetes lead to protein carbonyls formation in platelets, and this modification can be attenuated by antioxidant enzymes.

  7. Engineered Trx2p industrial yeast strain protects glycolysis and fermentation proteins from oxidative carbonylation during biomass propagation

    Directory of Open Access Journals (Sweden)

    Gómez-Pastor Rocío

    2012-01-01

    Full Text Available Abstract Background In the yeast biomass production process, protein carbonylation has severe adverse effects since it diminishes biomass yield and profitability of industrial production plants. However, this significant detriment of yeast performance can be alleviated by increasing thioredoxins levels. Thioredoxins are important antioxidant defenses implicated in many functions in cells, and their primordial functions include scavenging of reactive oxygen species that produce dramatic and irreversible alterations such as protein carbonylation. Results In this work we have found several proteins specifically protected by yeast Thioredoxin 2 (Trx2p. Bidimensional electrophoresis and carbonylated protein identification from TRX-deficient and TRX-overexpressing cells revealed that glycolysis and fermentation-related proteins are specific targets of Trx2p protection. Indeed, the TRX2 overexpressing strain presented increased activity of the central carbon metabolism enzymes. Interestingly, Trx2p specifically preserved alcohol dehydrogenase I (Adh1p from carbonylation, decreased oligomer aggregates and increased its enzymatic activity. Conclusions The identified proteins suggest that the fermentative capacity detriment observed under industrial conditions in T73 wine commercial strain results from the oxidative carbonylation of specific glycolytic and fermentation enzymes. Indeed, increased thioredoxin levels enhance the performance of key fermentation enzymes such as Adh1p, which consequently increases fermentative capacity.

  8. Engineered Trx2p industrial yeast strain protects glycolysis and fermentation proteins from oxidative carbonylation during biomass propagation.

    Science.gov (United States)

    Gómez-Pastor, Rocío; Pérez-Torrado, Roberto; Cabiscol, Elisa; Ros, Joaquim; Matallana, Emilia

    2012-01-09

    In the yeast biomass production process, protein carbonylation has severe adverse effects since it diminishes biomass yield and profitability of industrial production plants. However, this significant detriment of yeast performance can be alleviated by increasing thioredoxins levels. Thioredoxins are important antioxidant defenses implicated in many functions in cells, and their primordial functions include scavenging of reactive oxygen species that produce dramatic and irreversible alterations such as protein carbonylation. In this work we have found several proteins specifically protected by yeast Thioredoxin 2 (Trx2p). Bidimensional electrophoresis and carbonylated protein identification from TRX-deficient and TRX-overexpressing cells revealed that glycolysis and fermentation-related proteins are specific targets of Trx2p protection. Indeed, the TRX2 overexpressing strain presented increased activity of the central carbon metabolism enzymes. Interestingly, Trx2p specifically preserved alcohol dehydrogenase I (Adh1p) from carbonylation, decreased oligomer aggregates and increased its enzymatic activity. The identified proteins suggest that the fermentative capacity detriment observed under industrial conditions in T73 wine commercial strain results from the oxidative carbonylation of specific glycolytic and fermentation enzymes. Indeed, increased thioredoxin levels enhance the performance of key fermentation enzymes such as Adh1p, which consequently increases fermentative capacity.

  9. The effect of occupational lead exposure on lipid peroxidation, protein carbonylation, and plasma viscosity.

    Science.gov (United States)

    Kasperczyk, Sławomir; Słowińska-Łożyńska, Ludmiła; Kasperczyk, Aleksandra; Wielkoszyński, Tomasz; Birkner, Ewa

    2015-12-01

    The aim of the study was to investigate the influence of occupational lead (Pb) exposure on lipid peroxidation, protein carbonylation, and plasma viscosity in workers. The examined group included 283 healthy male employees of manufacturing facilities using zinc and Pb. The mean blood concentrations of Pb and zinc protoporphyrin as well as the mean urine δ-aminolevulinic acid levels were used as markers of exposure for the examined group. Taking into account the obtained mean values of blood lead level, the examined group was divided into three subgroups. When comparing the control group with the subgroups, Pb exposure markers were significantly elevated in all the three subgroups. Concentrations of conjugated dienes (CD), lipid hydroperoxides, malondialdehyde (MDA), and protein carbonyl groups were also significantly increased. Conversely, the levels of total protein and protein sulfhydryls were significantly decreased in the subgroups compared with the controls. The plasma viscosity was significantly elevated in the subgroups. A dose-response between Pb levels and plasma viscosity was not observed. Pb supposedly elevates MDA and CD in a dose-dependent manner. In conclusion, occupational Pb exposure induces oxidative stress that results in lipid and protein damage. Moreover, Pb-induced oxidative stress is likely the primary factor that elevates plasma viscosity, despite decreased protein levels. © The Author(s) 2012.

  10. Determination of carbonyl compounds (acetaldehyde and formaldehyde in polyethylene terephthalate containers designated for water conservation

    Directory of Open Access Journals (Sweden)

    Redžepović Azra S.

    2012-01-01

    Full Text Available Polyethylene terephthalate (PET has in the last several years become the main packaging material for many food products, particularly carbonated beverages and bottled water, as well as for products of chemical industry (packaging of various hygiene maintenance agents, pesticides, solvents, etc.. The strength and permeability properties of PET are very good for packaging of beverages, its resistance to chemicals is high and it has a high degree of transparency. Acetaldehyde and formaldehyde are formed during the thermoforming of PET containers. After cooling, acetaldehyde and formaldehyde remain trapped in the walls of a PET bottle and may migrate into the water after filling and storage. Since there are no migration tests in Serbia prescribed for the determination of acetaldehyde and formaldehyde, the purpose of the paper is to test the quantitative contents of carbonyl compounds (acetaldehyde and formaldehyde in PET containers of different volumes, made by various manufacturers of bottled mineral carbonated and noncarbonated water, and exposed to different temperatures. In this study, the migration of acetaldehyde and formaldehyde from PET bottles into mineral carbonated and noncarbonated water was determined by high performance liquid chromatography. Taking into consideration that formaldehyde and acetaldehyde have no UV active or fluorescent group, the chromatography shall be preceded by derivatization in a closed system (due to a low boiling point of acetaldehyde and formaldehyde, which shall transform carbonyl compounds into UV active compounds.

  11. Slurry-phase Fischer-Tropsch synthesis and kinetic studies over supported cobalt carbonyl derived catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Withers, H.P. Jr.; Eliezer, K.F.; Mitchell, J.W. (Air Products and Chemicals, Inc., Allentown, PA (USA))

    1990-09-01

    This paper reports the preparation characterization, and performance of cobalt carbonyl cluster based catalysts for use in slurry-phase Fischer--Tropsch (FT) technology investigated. Using metal carbonyls as active metal precursors allows for the control of metal particle size on the support surface, thus offering the potential for better control of activity and selectivity of the FT reaction. Silica as the support provided the highest catalyst activities. A Co{sub 2}(CO){sub 8}/Zr(OPr){sub 4}/SiO{sub 2} catalyst (3.5% cobalt, 6.6% zirconium) was developed as the most active system in the FT slurry reactor and also gave the best liquid fuel selectivity. Selectivity patterns correlated to the Schulz--Flory prediction. These catalysts exhibited low water/gas shift activity. Diesel fuel product produced by this catalyst was high quality. A kinetic expression that took water inhibition into account was verified, yielding an activation energy of 97 kJ/mol for syngas conversion ranging from 34% to 71% at 240--280{degrees} C.

  12. Impact of silica-coating on the microwave absorption properties of carbonyl iron powder

    Energy Technology Data Exchange (ETDEWEB)

    Li, J. [School of Science, Lanzhou University of Technology, Lanzhou, Gansu 730050 (China); Feng, W.J., E-mail: wjfeng@lut.cn [State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metal, Lanzhou University of Technology, Lanzhou 730050 (China); School of Science, Lanzhou University of Technology, Lanzhou, Gansu 730050 (China); Wang, J.S.; Zhao, X.; Zheng, W.Q. [School of Science, Lanzhou University of Technology, Lanzhou, Gansu 730050 (China); Yang, H. [State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metal, Lanzhou University of Technology, Lanzhou 730050 (China); School of Science, Lanzhou University of Technology, Lanzhou, Gansu 730050 (China)

    2015-11-01

    Microwave absorption properties, especially the band width and depth of reflection loss are highlighted as key measurement in studies of microwave absorber. In order to improve the band width and depth of reflection loss of carbonyl iron powder (CIP), we prepared SiO{sub 2} layers on the surface of CIP by using tetraethyl orthosilicate (TEOS) as a SiO{sub 2} source and 3-aminopropyl triethoxysilane (APTES) as a surface modifier. SiO{sub 2} layer was formed by the hydrolysis of TEOS. The results show that after treatment the CIP is covered by a 5–10 nm coating layer. Contrast to uncoated samples, coated samples show improved absorption properties. The minimum of reflection loss is −38.8 dB at 11 GHz and the band width of reflection loss exceeding −10 dB is from 8 GHz to 14 GHz. - Highlights: • Silica coatings were prepared on the surface of carbonyl iron powder. • Coating layers were identified by several ways. • We discussed the absorbing mechanism of coated samples. • Reflection loss was significantly improved, the width of RL exceeding −10 dB is from 8 GHz to 14 GHz.

  13. Carbonylation as a key reaction in anaerobic acetone activation by Desulfococcus biacutus.

    Science.gov (United States)

    Gutiérrez Acosta, Olga B; Hardt, Norman; Schink, Bernhard

    2013-10-01

    Acetone is activated by aerobic and nitrate-reducing bacteria via an ATP-dependent carboxylation reaction to form acetoacetate as the first reaction product. In the activation of acetone by sulfate-reducing bacteria, acetoacetate has not been found to be an intermediate. Here, we present evidence of a carbonylation reaction as the initial step in the activation of acetone by the strictly anaerobic sulfate reducer Desulfococcus biacutus. In cell suspension experiments, CO was found to be a far better cosubstrate for acetone activation than CO2. The hypothetical reaction product, acetoacetaldehyde, is extremely reactive and could not be identified as a free intermediate. However, acetoacetaldehyde dinitrophenylhydrazone was detected by mass spectrometry in cell extract experiments as a reaction product of acetone, CO, and dinitrophenylhydrazine. In a similar assay, 2-amino-4-methylpyrimidine was formed as the product of a reaction between acetoacetaldehyde and guanidine. The reaction depended on ATP as a cosubstrate. Moreover, the specific activity of aldehyde dehydrogenase (coenzyme A [CoA] acylating) tested with the putative physiological substrate was found to be 153 ± 36 mU mg(-1) protein, and its activity was specifically induced in extracts of acetone-grown cells. Moreover, acetoacetyl-CoA was detected (by mass spectrometry) after the carbonylation reaction as the subsequent intermediate after acetoacetaldehyde was formed. These results together provide evidence that acetoacetaldehyde is an intermediate in the activation of acetone by sulfate-reducing bacteria.

  14. Oxidative stress and protein carbonylation in adipose tissue - implications for insulin resistance and diabetes mellitus.

    Science.gov (United States)

    Ruskovska, Tatjana; Bernlohr, David A

    2013-10-30

    While historically considered simply as a depot for excess energy, white adipose tissue is a dynamically active endocrine organ capable of responding to a variety of efferent stimuli resulting in the synthesis and secretion of peptides, proteins and metabolites that serve as signal transducers to the peripheral and central circulation. Such regulation controls a variety of physiological processes including energy expenditure, food intake, reproductive capacity and responsiveness to insulin. Indeed, the accumulation of inflammatory cells in white adipose tissue is considered to be causative in the development of insulin resistance and eventually type 2 diabetes mellitus. A large body of evidence suggests that oxidative stress in adipose tissue not only correlates with insulin resistance but is also causative in its development. Moreover, using the available plasma oxidative stress biomarkers, many clinical studies have shown the presence of systemic oxidative stress in obese insulin resistant subjects, and its decrease after the successful treatment of obesity. In this review we emphasize the role of protein carbonylation in dysfunctional obese white adipose tissue and its metabolic implications. We focus on glutathione S-transferase A4 as the key enzyme for trans-4-hydroxy-2-nonenal and trans-4-oxo-2-nonenal removal from the cell, thus preventing protein carbonylation. This article is part of a Special Issue entitled: Posttranslational Protein modifications in biology and Medicine. Copyright © 2013 Elsevier B.V. All rights reserved.

  15. Lipid carbonyl groups terminate the hydrogen bond network of membrane-bound water.

    Science.gov (United States)

    Ohto, Tatsuhiko; Backus, Ellen H G; Hsieh, Cho-Shuen; Sulpizi, Marialore; Bonn, Mischa; Nagata, Yuki

    2015-11-19

    We present a combined experimental sum-frequency generation (SFG) spectroscopy and ab initio molecular dynamics simulations study to clarify the structure and orientation of water at zwitterionic phosphatidylcholine (PC) lipid and amine N-oxide (AO) surfactant monolayers. Simulated O-H stretch SFG spectra of water show good agreement with the experimental data. The SFG response at the PC interface exhibits positive peaks, whereas both negative and positive bands are present for the similar zwitterionic AO interface. The positive peaks at the water/PC interface are attributed to water interacting with the lipid carbonyl groups, which act as efficient hydrogen bond acceptors. This allows the water hydrogen bond network to reach, with its (up-oriented) O-H groups, into the headgroup of the lipid, a mechanism not available for water underneath the AO surfactant. This highlights the role of the lipid carbonyl group in the interfacial water structure at the membrane interface, namely, stabilizing the water hydrogen bond network.

  16. Palladium-catalyzed oxidative carbonylation of alkyl and aryl indium reagents with CO under mild conditions.

    Science.gov (United States)

    Zhao, Yingsheng; Jin, Liqun; Li, Peng; Lei, Aiwen

    2008-07-23

    CO now can react with organoindium reagents. A novel palladium-catalyzed oxidative carbonylation reaction of organoindium reagents by CO gas with desyl chloride as oxidant was developed in supplementation with the classical methods for preparation of carboxylic acid derivatives. Primary, secondary alkyl indium reagents with beta-hydrogens and aryl indium reagents were suitable substrates, and the reaction could be carried out at 60 degrees C under 50 psi CO. Carbonylation of alkyl indium reagents can occur smoothly without additional base. Although the indium reagents were prepared from corresponding Grignard reagents (at low temperature), they displayed full compatibility with various functional groups under the protic reaction conditions. Preliminary mechanistic studies including stoichiometric and catalytic reaction examination provided evidence to support the operation of the mechanism consisted of oxidative addition of deslyl chloride to Pd(0) and quick tautomerization to give a palladium enolate species II (ROPdCl), displacement of the enolate group in II by R(2)OH, followed by CO insertion to give alkoxycarbonyl palladium complex V, which undergoes transmetalation with R(1)(3)In and reductive elimination to afford the product and a Pd(0) species. In this mechanism, the alkoxycarbonyl group was transferred to the palladium center prior to the alkyl group, different from traditional ways initiated from oxidative addition of alkyl halides to a Pd(0) species.

  17. Arbutin blocks defects in the ripple phase of DMPC bilayers by changing carbonyl organization.

    Science.gov (United States)

    Frías, M A; Nicastro, A; Casado, N M C; Gennaro, A M; Díaz, S B; Disalvo, E A

    2007-05-01

    The effect of arbutin, a 4-hydroxyphenyl-beta-glucopyranoside, on dimyristoylphosphatidylcholine (DMPC) bilayers was studied by turbidimetry, EPR and FTIR spectroscopies. The disruption of DMPC multilamellar vesicles (MLV's) with monomyristoylphosphatidylcholine (lysoPC), a product of hydrolysis of phospholipase A(2) (PLA(2)), is more efficient at 18 degrees C, where DMPC MLV's are known to be in the ripple P(beta') phase, than at 10 degrees C (L(beta') flat gel phase). Disruption at 18 degrees C was inhibited by increasing concentrations of arbutin in the solution. This inhibition was correlated with the disappearance of the ripple phase in MLV's when arbutin is present. Shifts in FTIR carbonyl bands caused by arbutin or by temperature changes allow us to propose a model. It is interpreted that the changes in the water-hydrocarbon interface caused by arbutin, forcing a reaccommodation of the carbonyl groups, eliminate the topological defects in the lattice due to mismatches among regions with different area per lipid where lysoPC can insert.

  18. Toward Green Acylation of (Heteroarenes: Palladium-Catalyzed Carbonylation of Olefins to Ketones

    Directory of Open Access Journals (Sweden)

    Jie Liu

    2017-11-01

    Full Text Available Green Friedel–Crafts acylation reactions belong to the most desired transformations in organic chemistry. The resulting ketones constitute important intermediates, building blocks, and functional molecules in organic synthesis as well as for the chemical industry. Over the past 60 years, advances in this topic have focused on how to make this reaction more economically and environmentally friendly by using green acylating conditions, such as stoichiometric acylations and catalytic homogeneous and heterogeneous acylations. However, currently well-established methodologies for their synthesis either produce significant amounts of waste or proceed under harsh conditions, limiting applications. Here, we present a new protocol for the straightforward and selective introduction of acyl groups into (hetero­arenes without directing groups by using available olefins with inexpensive CO. In the presence of commercial palladium catalysts, inter- and intramolecular carbonylative C–H functionalizations take place with good regio- and chemoselectivity. Compared to classical Friedel–Crafts chemistry, this novel methodology proceeds under mild reaction conditions. The general applicability of this methodology is demonstrated by the direct carbonylation of industrial feedstocks (ethylene and diisobutene as well as of natural products (eugenol and safrole. Furthermore, synthetic applications to drug molecules are showcased.

  19. Penicitroamide, an Antimicrobial Metabolite with High Carbonylization from the Endophytic Fungus Penicillium sp. (NO. 24

    Directory of Open Access Journals (Sweden)

    Zi-Wei Feng

    2016-10-01

    Full Text Available Penicitroamide (1, a new metabolite with a new framework, was isolated from the ethyl acetate extract of the PDB (Potato Dextrose Broth medium of Penicillium sp. (NO. 24. The endophytic fungus Penicillium sp. (NO. 24 was obtained from the healthy leaves of Tapiscia sinensis Oliv. The structure of penicitroamide (1 features a bicyclo[3.2.1]octane core unit with a high degree of carbonylization (four carbonyl groups and one enol group. The chemical structure of penicitroamide (1 was elucidated by analysis of 1D-, 2D-NMR and MS data. In bioassays, penicitroamide (1 displayed antibacterial potency against two plant pathogens, Erwinia carotovora subsp. Carotovora (Jones Bersey, et al. and Sclerotium rolfsii Sacc. with MIC50 at 45 and 50 μg/mL. Compound 1 also showed 60% lethality against brine shrimp at 10 μg/mL. Penicitroamide (1 exhibited no significant activity against A549, Caski, HepG2 and MCF-7 cells with IC50 > 50 μg/mL. Finally, the possible biosynthetic pathway of penicitroamide (1 was discussed.

  20. Enantioselective Iridium Catalyzed Carbonyl Allylation from the Alcohol or Aldehyde Oxidation Level via Transfer Hydrogenative Coupling of Allyl Acetate: Departure from Chirally Modified Allyl Metal Reagents in Carbonyl Addition

    OpenAIRE

    Kim, In Su; Ngai, Ming-Yu; Krische, Michael J.

    2008-01-01

    Under the conditions of transfer hydrogenation employing an iridium catalyst generated in situ from [Ir(cod)Cl]2, the chiral phosphine ligands (R)-BINAP or (R)-Cl,MeO-BIPHEP and m-nitrobenzoic acid, allyl acetate couples to allylic alcohols 1a-1c, aliphatic alcohols 1d-1l and benzylic alcohols 1m-1u to furnish products of carbonyl allylation 3a-3u with exceptional levels of asymmetric induction. The very same set of optically enriched carbonyl allylation products 3a-3u are accessible from ena...

  1. Application of vanadium incorporated phosphomolybdate supported on the modified kaolinin synthesis of diphenyl carbonate by oxidative carbonylation with phenol

    Directory of Open Access Journals (Sweden)

    Peng Meng

    2017-01-01

    Full Text Available Keggin-type molybdophosphoric acid, molybdophosphoric salt and vanadium incorporated molybdophosphoric salt supported on the modified kaolin (MK were investigated as redox co-catalysts for the oxidative carbonylation of phenol to diphenyl carbonate (DPC in the absence of solvent. The 20 wt.% of MnAMPV5 (one kind of vanadium incorporated molybdophosphoric salt loaded on MK showed the highest catalytic activity with the yield of 24.68% and a TON of 306, while the selectivity amounts to nearly 100% in all the carbonylation reactions. The catalysts were characterized by XRD, BET, XPS and H2-TPR. The reusability study showed that the catalysts were stable and active.

  2. Enhanced anti-Diastereo- and Enantioselectivity in Alcohol Mediated Carbonyl Crotylation Using an Isolable Single Component Iridium Catalyst

    Science.gov (United States)

    Gao, Xin; Townsend, Ian A.; Krische, Michael J.

    2011-01-01

    The cyclometallated iridium complex (S)-I derived from [Ir(cod)Cl]2, 4-cyano-3-nitrobenzoic acid, allyl acetate and (S)-SEGPHOS is conveniently isolated by precipitation or through conventional silica gel flash chromatography. This single component precatalyst allows alcohol mediated carbonyl crotylations to be performed at significantly lower temperature, resulting in enhanced levels of anti-diastereo- and enantioselectivity. Most significantly, the chromatographically isolated precatalyst (S)-I enables carbonyl crotylations that are not possible under previously reported conditions involving in situ generation of (S)-I. PMID:21375283

  3. 1-Ethyl-3-methylimidazolium acetate as a highly efficient organocatalyst for cyanosilylation of carbonyl compounds with trimethylsilyl cyanide

    Science.gov (United States)

    Ullah, Bakhtar; Chen, Jingwen; Zhang, Zhiguo; Xing, Huabin; Yang, Qiwei; Bao, Zongbi; Ren, Qilong

    2017-02-01

    1-Ethyl-3-methylimidazolium acetate is introduced as a robust organocatalyst for solvent-free cyanosilylation of carbonyl compounds with trimethylsilyl cyanide (TMSCN). The catalyst loading can be reduced to as low as 0.1-0.0001 mol % under mild reaction conditions, giving considerably high TOF values from 10,843 h-1 to 10,602,410 h-1 in the field of organocatalyzed transformations. The present protocol not only tolerates with extensive carbonyl compounds but also provides somewhat insight into the mechanism of ionic liquids (ILs)-catalyzed reactions.

  4. Effect of the direction of ester linkage on molecular shape selectivity through multiple carbonyl-pi interaction with octadecyl chain branched polymers as organic phases in reversed-phase high-performance liquid chromatography.

    Science.gov (United States)

    Rana, Ashequl A; Takafuji, Makoto; Ihara, Hirotaka

    2009-10-30

    Poly(vinyl octadecanoate)-grafted porous silica (Sil-VODn, n=23) was newly prepared to investigate the efficiencies of the carbonyl groups in the polymer chain for recognition of polycyclic aromatic hydrocarbons (PAHs) in RP-HPLC. In Sil-VOD23, the octadecyl side chains were connected to the polymer main chain through ester linkage in opposite direction to that in poly(octadecylacrylate)-grafted silica (Sil-ODAn, n=25) which has been reported by us. Sil-ODAn performs enhanced molecular shape selectivity of PAHs in RP-HPLC through multiple carbonyl-pi interaction of aligned carbonyl groups which are induced by the formation of highly oriented structure of side chains. Differential scanning calorimetry of VOD23 demonstrated that octadecyl alkyl chains showed crystalline to isotropic phase transition with endothermic peak at 48.7 degrees C which was similar to ODA25 (at 47.8 degrees C). After grafting of both polymers, phase transition phenomenon was completely disappeared in Sil-VOD23 whereas Sil-ODA25 still exhibits phase transition although at lower endothermic peak top temperature (38.5 degrees C). This indicates that the slight structural change in Sil-VODn and Sil-ODAn influence the ordered structure of side alkyl chains. Moreover, solid-state 13C NMR revealed that the long alkyl chain in Sil-VOD23 is highly disordered as compared with that of Sil-ODA25. Sil-VOD23 was applied to RP-HPLC stationary phase using PAHs as pi-electron containing elutes, and compared with Sil-ODA25 and conventional monomeric octadecylated silica (ODS). Results confirmed that Sil-VOD23 showed much higher selectivity for PAH isomers than ODS, but lower than Sil-ODA25. For example, the separation factors for trans-/cis-stilbene were 1.47 (Sil-VOD23), 1.70 (Sil-ODA25) and 1.07 (ODS), respectively. These results indicate that carbonyl groups in Sil-VOD23 are effective for molecular shape recognition of PAHs through carbonyl-pi interactions even in the disordered state.

  5. Hydrothermal synthesis of carbonyl iron-carbon nanocomposite: Characterization and electromagnetic performance

    Directory of Open Access Journals (Sweden)

    Hakimeh Pourabdollahi

    Full Text Available In this research, the electromagnetic absorption properties of the carbonyl iron-carbon (CI/C nanocomposite prepared via hydrothermal reaction using glucose as carbon precursor was studied in the range of 8.2–12.4 GHz. In hydrothermal reaction, glucose solution containing CI particles, placed in autoclave for 4 h under 453 K. Using surface coating technology is a method that prevents Cl oxidation and improves CI electromagnetic absorption. The structure, morphology and magnetic performances of the prepared nanocomposites were characterized by X-ray diffraction (XRD, energy dispersive spectrometry (EDS, transmission electron microscopy (TEM and vibrating sample magnetometer (VSM. The electromagnetic properties including complex permittivity (εr, the permeability (µr, dielectric loss, magnetic loss, reflection loss, and attenuation constant were investigated using a vector network analyzer. For The CI/C nanocomposite, the bandwidth of −10 dB and −20 dB were obtained in the frequency range of 9.8–12.4 and 11.0–11.8 GHz, respectively. As well as, the reflection loss was −46.69 dB at the matching frequency of 11.5 GHz, when the matching thickness was 1.3 mm. While for CI particles the reflection loss for 4.4 mm thickness was −16.86 dB at the matching frequency of 12.3 GHz. The results indicate that the existence layer of carbon on carbonyl iron enhance the electromagnetic absorbing properties. Therefore, this nanocomposite can be suitable for in the radar absorbing coatings. Keywords: Hydrothermal synthesis, Carbonyl iron-carbon nanocomposite, Microwave absorption, Reflection loss

  6. [carbonyl-C-11]desmethyl-WAY-100635 (DWAY) is a potent and selective radioligand for central 5-HT1A receptors in vitro and in vivo

    NARCIS (Netherlands)

    Pike, VW; Halldin, C; McCarron, JA; Lundkvist, C; Hirani, E; Olsson, H; Hume, SP; Karlsson, P; Osman, S; Swahn, CG; Hall, H; Wikstrom, H; Mensonidas, M; Poole, KG; Farde, L

    [carbonyl-C-11]Desmethyl-WAY-100635 (DWAY) is possibly a low-level metabolite appearing in plasma after intravenous administration of [carbonyl(11)C]WAY-100635 to human subjects for positron emission tomographic (PET) imaging of brain 5-HT1A receptors. In this study we set out to assess the ability

  7. Synthesis of high refractive spiro heterocyclic derivatives through thioacetalization of multi-carbonyl compounds

    Energy Technology Data Exchange (ETDEWEB)

    Ye, Jim Young; Maheswara, Muchchintala; Do, Jung Yun [Pusan National Univ., Busan (Korea, Republic of)

    2012-04-15

    Preparation of several new spirocyclic mercaptol derivatives is described. Thiol protection on multi-carbonyl compounds allows of high sulfur content necessary to induce high refractive index. Condensation of 1,3-dimercapto-2-propanol and cyclohexanone followed by successive oxidation and thioacetalization affords a dispiro cycle with four sulfurs. Selective S,S-protection of cyclohexane-1,4-dione is achieved with 1,3-dimercapto-2-propanol and 2,3-dimercapto-1-propanol to provide dispiro cycles with four sulfurs. Olefineoxidation of norbornene gives a useful dialdehyde intermediate which is transformed to 1,3-dithiolane for a linearly-bound-cyclic molecule. Refractive index of linearly-bound-cycles was below 1.60 and dispiro cycles exhibited high refractive index of 1.57-1.69.

  8. Chemoenzymatic synthesis of (S)-duloxetine using carbonyl reductase from Rhodosporidium toruloides.

    Science.gov (United States)

    Chen, Xiang; Liu, Zhi-Qiang; Lin, Chao-Ping; Zheng, Yu-Guo

    2016-04-01

    A chemoenzymatic strategy was developed for (S)-duloxetine production employing carbonyl reductases from newly isolated Rhodosporidium toruloides into the enantiodetermining step. Amongst the ten most permissive enzymes identified, cloned, and overexpressed in Escherichia coli, RtSCR9 exhibited excellent activity and enantioselectivity. Using co-expressed E. coli harboring both RtSCR9 and glucose dehydrogenase, (S)-3-(dimethylamino)-1-(2-thienyl)-1-propanol 3a was fabricated with so far the highest substrate loading (1000mM) in a space-time yield per gram of biomass (DCW) of 22.9mmolL(-1)h(-1)gDCW(-1) at a 200-g scale. The subsequent synthetic steps from RtSCR9-catalyzed (S)-3a were further performed, affording (S)-duloxetine with 60.2% overall yield from 2-acethylthiophene in >98.5% ee. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Reaction mechanism of dimethyl ether carbonylation to methyl acetate over mordenite

    DEFF Research Database (Denmark)

    Rasmussen, Dominik Bjørn; Christensen, Jakob Munkholt; Temel, B.

    2017-01-01

    concentrations in CO between 0.2 and 2.0%, and at a temperature of 438 K. The theoretical study showed that the reaction of CO with surface methyl groups, the rate-limiting step, is faster in the eight-membered side pockets than in the twelve-membered main channel of the zeolite; the subsequent reaction......The reaction mechanism of dimethyl ether carbonylation to methyl acetate over mordenite was studied theoretically with periodic density functional theory calculations including dispersion forces and experimentally in a fixed bed flow reactor at pressures between 10 and 100 bar, dimethyl ether...... of dimethyl ether with surface acetyl to form methyl acetate was demonstrated to occur with low energy barriers in both the side pockets and in the main channel. The present analysis has thus identified a path, where the entire reaction occurs favourably on a single site within the side pocket, in good...

  10. Effect of Powder Morphologies on the Property of Conductive Silicone Rubber Filled with Carbonyl Nickel Powder

    Science.gov (United States)

    Xiao, Weimin; Lei, Yongping; Xia, Zhidong; Chen, Xin; Han, Yu; Nie, Jingkai; Huang, Pei

    2017-11-01

    Conductive silicone rubbers filled with the spherical, flaky, and chain-spherical carbonyl nickel powder were prepared. The effects of powder morphologies on their electromagnetic and mechanical properties were analyzed. The electromagnetic shielding effectiveness (SE) and tensile strength of the rubbers varies with their powder morphologies: the SE values increase from the spherical and the chain-spherical to the flaky morphology in the frequency range of 100-400 MHz. In the range of 500-1500 MHz, the SE rises from the spherical and the flaky to the chain-spherical morphologies. In addition, the tensile strength increases from the spherical and the flaky to the chain-spherical morphologies. These variations are related to the differences in the conductive network structure and the powder distribution in the rubber.

  11. Ionization of oriented carbonyl sulfide molecules by intense circularly polarized laser pulses

    DEFF Research Database (Denmark)

    Dimitrovski, Darko; Abu-Samha, Mahmoud; Madsen, Lars Bojer

    2011-01-01

    We present combined experimental and theoretical results on strong-field ionization of oriented carbonyl sulfide molecules by circularly polarized laser pulses. The obtained molecular frame photoelectron angular distributions show pronounced asymmetries perpendicular to the direction...... of the molecular electric dipole moment. These findings are explained by a tunneling model invoking the laser-induced Stark shifts associated with the dipoles and polarizabilities of the molecule and its unrelaxed cation. The focus of the present article is to understand the strong-field ionization of one......-dimensionally-oriented polar molecules, in particular asymmetries in the emission direction of the photoelectrons. In the following article [Phys. Rev. A 83, 023406 (2011)] the focus is to understand strong-field ionization from three-dimensionally-oriented asymmetric top molecules, in particular the suppression of electron...

  12. Impact of silica-coating on the microwave absorption properties of carbonyl iron powder

    Science.gov (United States)

    Li, J.; Feng, W. J.; Wang, J. S.; Zhao, X.; Zheng, W. Q.; Yang, H.

    2015-11-01

    Microwave absorption properties, especially the band width and depth of reflection loss are highlighted as key measurement in studies of microwave absorber. In order to improve the band width and depth of reflection loss of carbonyl iron powder (CIP), we prepared SiO2 layers on the surface of CIP by using tetraethyl orthosilicate (TEOS) as a SiO2 source and 3-aminopropyl triethoxysilane (APTES) as a surface modifier. SiO2 layer was formed by the hydrolysis of TEOS. The results show that after treatment the CIP is covered by a 5-10 nm coating layer. Contrast to uncoated samples, coated samples show improved absorption properties. The minimum of reflection loss is -38.8 dB at 11 GHz and the band width of reflection loss exceeding -10 dB is from 8 GHz to 14 GHz.

  13. Temporal variation of carbonyl compound concentrations at a semi-rural site in Denmark

    DEFF Research Database (Denmark)

    Christensen, C.S.; Skov, H.; Nielsen, T.

    2000-01-01

    The atmospheric concentrations of formaldehyde, acetaldehyde and acetone were measured by the DNPH-technique at the semi-rural site Lille Valby, Denmark (55 degrees N) between May-July 1995, The average concentrations were observed to be 1.2 ppbv for formaldehyde, 0.8 ppbv for acetaldehyde and 1.......9 ppbv for acetone, For the set of carbonyl compounds, concentrations were found to be highly correlated, though only during daytime, The weak correlations observed during nighttime are believed to be caused by the dry deposition of especially formaldehyde, During periods with low photochemical activity...... of hydrocarbons during long-range transport. Especially, the concentration levels of acetone showed a pronounced seasonal-variation with the highest levels observed during summertime and lowest in winter and spring. The seasonal variation in the concentration levels of formaldehyde and acetaldehyde were small...

  14. Formation and emissions of carbonyls during and following gas-phase ozonation of indoor materials

    DEFF Research Database (Denmark)

    Poppendieck, D.G.; Hubbard, H.F.; Weschler, Charles J.

    2007-01-01

    at concentrations of 1000 ppm in the inlet stream of experimental chambers. Fifteen target carbonyls were selected and measured as building ozonation by-products (BOBPs). During the 36 h that include the 16 h ozonation and 20 h persistence phase, the total BOBP mass released from flooring and wall coverings ranged......Ozone concentrations that are several orders of magnitude greater than typical urban ambient concentrations are necessary for gas-phase ozonation of buildings, either for deodorization or for disinfection of biological agents. However, there is currently no published literature on the interaction...... of building materials and ozone under such extreme conditions. It would be useful to understand, for example in the case of building re-occupation planning, what types and amounts of reaction products may form and persist in a building after ozonation. In this study, 24 materials were exposed to ozone...

  15. Synthesis and Crystal Structure of a New Triosmium Alkylidyne Carbonyl Cluster Containing a Chiral Ferrocenylphosphine Ligand

    Directory of Open Access Journals (Sweden)

    Wai-Yeung Wong

    2005-07-01

    Full Text Available The synthesis, spectroscopic characterization and X-ray crystal structure of a newchiral triosmium alkylidyne carbonyl cluster, (R,S-[Os3(μ-H2(CO9{��¼3-CPPh2(η5-C5H4Fe(η5-C5H3(PPh2CH(MeNMe2}] (1 are described. Compound 1 crystallizes in thenon-centrosymmetric space group P21 and its absolute configuration has been established.The structure consists of an Os3C metal core with one of the PPh2 moieties of the chiralferrocenylphosphine bonded to the apical alkylidyne carbon atom to give a zwitterioniccluster complex, reminiscent of the phosphorus yli

  16. Magnetorheology of suspensions based on graphene oxide coated or added carbonyl iron microspheres and sunflower oil

    Science.gov (United States)

    Chen, Kaikai; Zhang, Wen Ling; Shan, Lei; Zhang, Xiangjun; Meng, Yonggang; Choi, Hyoung Jin; Tian, Yu

    2014-10-01

    Magnetorheological (MR) fluids based on carbonyl iron (CI) particles coated with graphene oxide (GO) and sunflower oils were studied and compared with MR fluids (MRFs) prepared with CI particles added with GO sheets. Adding GO sheets into CI had a negligible effect on the rheological properties of the MRF. Coating the spheres with GO markedly decreased the shear strength at high shear rates due to the remarkable lubricating function of the GO surface. Different behaviors were observed in the shear thickening phenomenon when the GO surface changed the mechanical interaction between particles. The results demonstrated the importance of the role of interparticle friction for MRF in shear mode and discussed the weak shear thickening phenomenon with fine lubricating coating layers and oils.

  17. Microbial carbonylation and hydroxylation of 20(R)-panaxadiol by Aspergillus niger.

    Science.gov (United States)

    Yan, Bin; Chen, Zhihua; Zhai, Xuguang; Yin, Guibo; Ai, Yafei; Chen, Guangtong

    2018-04-01

    20(R)-panaxadiol (PD) was metabolised by the fungus Aspergillus niger AS 3.3926 to its C-3 carbonylated metabolite and five other hydroxylated metabolites (1-6). Their structures were elucidated as 3-oxo-20(R)-panaxadiol (1), 3-oxo-7β-hydroxyl- 20(R)-panaxadiol (2), 3-oxo-7β,23α-dihydroxyl-20(R)-panaxadiol (3), 3,12-dioxo- 7β,23β-dihydroxyl-20(R)-panaxadiol (4), 3-oxo-1α,7β-dihydroxyl-20(R)-panaxadiol (5) and 3-oxo-7β,15β-dihydroxyl-20(R)-panaxadiol (6) by spectroscopic analysis. Among them, compounds 2-6 were new compounds. Pharmacological studies revealed that compound 6 exhibited significant anti-hepatic fibrosis activity.

  18. Polishing characteristics of optical glass using PMMA-coated carbonyl-iron-based magnetorheological fluid

    Science.gov (United States)

    Lee, J. W.; Hong, K. P.; Cho, M. W.; Kwon, S. H.; Choi, H. J.

    2015-06-01

    Soft magnetic carbonyl iron (CI) particles for magnetorheological (MR) polishing encounter corrosion problems as a result of their oxidation, leading to unpredictable polishing results. To overcome this issue, CI particles have been coated with either polymer or inorganic materials for improved MR polishing. In this study, CI particles were coated with poly(methyl methacrylate) to achieve improved MR polishing and anti-corrosion protection. In addition to an analysis of their rheological properties, a series of MR polishing experiments were performed to investigate the material removal rate and surface roughness for BK7 optical glass by changing experimental parameters, such as the wheel rotating speed and magnetic field intensity. A very fine surface roughness (Ra = 0.86 nm for PMMA coated CI/Ra = 0.92 nm for pristine CI) was obtained at a wheel speed of 1256 mm s-1 and a magnetic field intensity of 15.92 kA m-1.

  19. The long underestimated carbonyl function of carbohydrates – an organocatalyzed shot into carbohydrate chemistry.

    Science.gov (United States)

    Mahrwald, R

    2015-09-21

    The aggressive and strong development of organocatalysis provides several protocols for the convenient utilization of the carbonyl function of unprotected carbohydrates in C-C-bond formation processes. These amine-catalyzed mechanisms enable multiple cascade-protocols for the synthesis of a wide range of carbohydrate-derived compound classes. Several, only slightly different protocols, have been developed for the application of 1,3-dicarbonyl compounds in the stereoselective chain-elongation of unprotected carbohydrates and the synthesis of highly functionalized C-glycosides of defined configuration. In addition, C-glycosides can also be accessed by amine-catalyzed reactions with methyl ketones. By a one-pot cascade reaction of isocyanides with unprotected aldoses and amino acids access to defined configured glycopeptide mimetics is achieved. Depending on the reaction conditions different origins to control the installation of configuration during the bond-formation process were observed.

  20. Protonation Sites, Tandem Mass Spectrometry and Computational Calculations of o-Carbonyl Carbazolequinone Derivatives

    Directory of Open Access Journals (Sweden)

    Maximiliano Martínez-Cifuentes

    2016-07-01

    Full Text Available A series of a new type of tetracyclic carbazolequinones incorporating a carbonyl group at the ortho position relative to the quinone moiety was synthesized and analyzed by tandem electrospray ionization mass spectrometry (ESI/MS-MS, using Collision-Induced Dissociation (CID to dissociate the protonated species. Theoretical parameters such as molecular electrostatic potential (MEP, local Fukui functions and local Parr function for electrophilic attack as well as proton affinity (PA and gas phase basicity (GB, were used to explain the preferred protonation sites. Transition states of some main fragmentation routes were obtained and the energies calculated at density functional theory (DFT B3LYP level were compared with the obtained by ab initio quadratic configuration interaction with single and double excitation (QCISD. The results are in accordance with the observed distribution of ions. The nature of the substituents in the aromatic ring has a notable impact on the fragmentation routes of the molecules.

  1. Comparative inhibition of tetrameric carbonyl reductase activity in pig heart cytosol by alkyl 4-pyridyl ketones.

    Science.gov (United States)

    Shimada, Hideaki; Tanigawa, Takahiro; Matayoshi, Kazunori; Katakura, Kazufumi; Babazono, Ken; Takayama, Hiroyuki; Murahashi, Tsuyoshi; Akita, Hiroyuki; Higuchi, Toshiyuki; Eto, Masashi; Imamura, Yorishige

    2014-06-01

    The present study is to elucidate the comparative inhibition of tetrameric carbonyl reductase (TCBR) activity by alkyl 4-pyridyl ketones, and to characterize its substrate-binding domain. The inhibitory effects of alkyl 4-pyridyl ketones on the stereoselective reduction of 4-benzoylpyridine (4-BP) catalyzed by TCBR were examined in the cytosolic fraction of pig heart. Of alkyl 4-pyridyl ketones, 4-hexanoylpyridine, which has a straight-chain alkyl group of five carbon atoms, inhibited most potently TCBR activity and was a competitive inhibitor. Furthermore, cyclohexyl pentyl ketone, which is substituted by cyclohexyl group instead of phenyl group of hexanophenone, had much lower ability to be reduced than hexanophenone. These results suggest that in addition to a hydrophobic cleft corresponding to a straight-chain alkyl group of five carbon atoms, a hydrophobic pocket with affinity for an aromatic group is located in the substrate-binding domain of TCBR.

  2. Inhibitory activity of carbonyl compounds on alcoholic fermentation by Saccharomyces cerevisiae.

    Science.gov (United States)

    Cao, Dongxu; Tu, Maobing; Xie, Rui; Li, Jing; Wu, Yonnie; Adhikari, Sushil

    2014-01-29

    Aldehydes and acids play important roles in the fermentation inhibition of biomass hydrolysates. A series of carbonyl compounds (vanillin, syringaldehyde, 4-hydroxybenzaldehyde, pyrogallol aldehyde, and o-phthalaldehyde) were used to examine the quantitative structure-inhibitory activity relationship of carbonyl compounds on alcoholic fermentation, based on the glucose consumption rate and the final ethanol yield. It was observed that pyrogallol aldehyde and o-phthalaldehyde (5.0 mM) reduced the initial glucose consumption rate by 60 and 89%, respectively, and also decreased the final ethanol yield by 60 and 99%, respectively. Correlating the molecular descriptors to inhibition efficiency in yeast fermentation revealed a strong relationship between the energy of the lowest unoccupied molecular orbital (ELUMO) of aldehydes and their inhibitory efficiency in fermentation. On the other hand, vanillin, syringaldehyde, and 4-hydroxybenzaldehyde (5.0 mM) increased the final ethanol yields by 11, 4, and 1%, respectively. Addition of vanillin appeared to favor ethanol formation over glycerol formation and decreased the glycerol yield in yeast fermentation. Furthermore, alcohol dehydrogenase (ADH) activity dropped significantly from 3.85 to 2.72, 1.83, 0.46, and 0.11 U/mg at 6 h of fermentation at vanillin concentrations of 0, 2.5, 5.0, 10.0, and 25.0 mM correspondingly. In addition, fermentation inhibition by acetic acid and benzoic acid was pH-dependent. Addition of acetate, benzoate, and potassium chloride increased the glucose consumption rate, likely because the salts enhanced membrane permeability, thus increasing glucose consumption.

  3. An intercomparison of aircraft instrumentation for tropospheric measurements of carbonyl sulfide, hydrogen sulfide, and carbon disulfide

    Science.gov (United States)

    Gregory, Gerald L.; Davis, Douglas D.; Thornton, Donald C.; Johnson, James E.; Bandy, Alan R.; Saltzman, Eric S.; Andreae, Meinrat O.; Barrick, John D.

    1993-01-01

    This paper reports results of NASA's Chemical Instrumentation and Test Evaluation (CITE 3) during which airborne measurements for carbonyl sulfide (COS), hydrogen sulfide (H2S), and carbon disulfide (CS2) were intercompared. Instrumentation included a gas chromatograph using flame photometric detection (COS, H2S, and CS2), a gas chromatograph using mass spectrometric detection (COS) and CS2), a gas chromatograph using fluorination and subsequent SF6 detection via electron capture (COS and CS2), and the Natusch technique (H2S). The measurements were made over the Atlantic Ocean east of North and South America during flights from NASA's Wallops Flight Center, Virginia, and Natal, Brazil, in August/September 1989. Most of the intercomparisons for H2S and CS2 were at mixing ratios less than 25 pptv and less than 10 pptv, respectively, with a maximum mixing ratio of about 100 pptv and 50 pptv, respectively. Carbonyl sulfide intercomparisons were at mixing ratios between 400 and 600 pptv. Measurements were intercompared from data bases constructed from time periods of simultaneous or overlapping measurements. Agreement among the COS techniques averaged about 5%, and individual measurements were generally within 10%. For H2S and at mixing ratio greater than 25 pptv, the instruments agreed on average to about 15%. At mixing ratios less than 25 pptv the agreement was about 5 pptv. For CS2 (mixing ratios less than 50 pptv), two techniques agreed on average to about 4 pptv, and the third exhibited a bias (relative to the other two) that varied in the range of 3-7 pptv. CS2 mixing ratios over the ocean east of Natal as measured by the gas chromatograph-mass spectrometer technique were only a few pptv and were below the detection limits of the other two techniques. The CITE 3 data are used to estimate the current uncertainty associated with aircraft measurements of COS, H2S, and CS2 in the remote troposphere.

  4. Carbonyl Stress in Aging Process: Role of Vitamins and Phytochemicals as Redox Regulators

    Science.gov (United States)

    Ergin, Volkan; Hariry, Reza Ebrahimi; Karasu, Çimen

    2013-01-01

    There is a growing scientific agreement that the cellular redox regulators such as antioxidants, particularly the natural polyphenolic forms, may help lower the incidence of some pathologies, including metabolic diseases like diabetes and diabesity, cardiovascular and neurodegenerative abnormalities, and certain cancers or even have anti-aging properties. The recent researches indicate that the degree of metabolic modulation and adaptation response of cells to reductants as well as oxidants establish their survival and homeostasis, which is linked with very critical balance in imbalances in cellular redox capacity and signaling, and that might be an answer the questions why some antioxidants or phytochemicals potentially could do more harm than good, or why some proteins lose their function by increase interactions with glyco- and lipo-oxidation mediates in the cells (carbonyl stress). Nonetheless, pursue of healthy aging has led the use of antioxidants as a means to disrupt age-associated physiological dysfunctions, dysregulated metabolic processes or prevention of many age-related diseases. Although it is still early to define their exact clinical benefits for treating age-related disease, a diet rich in polyphenolic or other forms of antioxidants does seem to offer hope in delaying the onset of age-related disorders. It is now clear that any deficiency in antioxidant vitamins, inadequate enzymatic antioxidant defenses can distinctive for many age-related disease, and protein carbonylation can used as an indicator of oxidative stress associated diseases and aging status. This review examines antioxidant compounds and plant polyphenols as redox regulators in health, disease and aging processes with hope that a better understanding of the many mechanisms involved with these distinct compounds, which may lead to better health and novel treatment approaches for age-related diseases. PMID:24124633

  5. Theoretical versus observed gas-particle partitioning of carbonyl emissions from motor vehicles.

    Science.gov (United States)

    Chen, Jianjun; Jakober, Chris; Clegg, Simon; Kleeman, Michael J

    2010-10-01

    A state-of-the-science thermodynamic model describing gas-particle absorption processes was used to predict the gas-particle partitioning of mixtures of approximately 60 carbonyl compounds emitted from low-emission gasoline-powered vehicles, three-way catalyst gasoline-powered vehicles, heavy-duty diesel vehicles under the idle-creep condition (HDDV idle), and heavy-duty diesel vehicles under the five-mode test (HDDV 5-mode). Exhaust was diluted by a factor of 120-580 with a residence time of approximately 43 sec. The predicted equilibrium absorption partitioning coefficients differed from the measured partitioning coefficients by several orders of magnitude. Time scales to reach equilibrium in the dilution sampling system were close to the actual residence time during the HDDV 5-mode test and much longer than the actual residence time during the other vehicle tests. It appears that insufficient residence time in the sampling system cannot uniformly explain the failure of the absorption mechanism to explain the measured partitioning. Other gas-particle partitioning mechanisms (e.g., heterogeneous reactions, capillary adsorption) beyond the simple absorption theory are needed to explain the discrepancy between calculated carbonyl partitioning coefficients and observed partitioning. Both of these alternative partitioning mechanisms imply great challenges for the measurement and modeling of semi-volatile primary organic aerosol (POA) species from motor vehicles. Furthermore, as emitted particle concentrations from newer vehicles approach atmospheric background levels, dilution sampling systems must fundamentally change their approach so that they use realistic particle concentrations in the dilution air to approximately represent real-world conditions. Samples collected with particle-free dilution air yielding total particulate matter concentrations below typical ambient concentrations will not provide a realistic picture of partitioning for semi-volatile compounds.

  6. Impact of trolox, quercetin, genistein and gallic acid on the oxidative damage to myofibrillar proteins: the carbonylation pathway.

    Science.gov (United States)

    Utrera, Mariana; Estévez, Mario

    2013-12-15

    The carbonylation pathway involves the oxidative deamination of lysine residues to yield a carbonyl compound (α-aminoadipic semialdehyde) that can be further oxidised to α-aminoadipic acid and form Schiff bases structures. The effect of trolox and other phenolic compounds (PhC) (namely genistein, quercetin and gallic acid) on the protein carbonylation pathway occurred during the oxidation of myofibrillar proteins (MP) catalysed by a Fe(3+)/H2O2 system was studied. Trolox and PhC can exert either antioxidant or pro-oxidant capacities depending on their concentration, the oxidation conditions and the target in proteins. In general, quercetin and genistein showed an antioxidant activity towards lipid oxidation and the carbonylation pathway at different concentrations under the analysed conditions. Plausible mechanisms for the antioxidant and pro-oxidant effects of trolox and PhC on MP are discussed. Further research is needed to shed light on the effect of PhC mixtures on both lipid and protein oxidation. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. Iodine-catalyzed addition of 2-mercaptoethanol to chalcone derivatives: Synthesis of the novel β-mercapto carbonyl compounds

    Directory of Open Access Journals (Sweden)

    Gürkan Yerli

    2012-01-01

    Full Text Available In this study, a series of novel β-mercapto carbonyl derivatives (3-(2-hydroxyethylthio-1,3-diarylpropan-1-one (5a-i were prepared by addition of 2-mercaptoethanol (4 to chalcones (3a-i in the presence of catalytic amount of iodine (10 mol % in CH 2Cl 2.

  8. Determination and Comparison of Carbonyl Stretching Frequency of a Ketone in Its Ground State and the First Electronic Excited State

    Science.gov (United States)

    Bandyopadhyay, Subhajit; Roy, Saswata

    2014-01-01

    This paper describes an inexpensive experiment to determine the carbonyl stretching frequency of an organic keto compound in its ground state and first electronic excited state. The experiment is simple to execute, clarifies some of the fundamental concepts of spectroscopy, and is appropriate for a basic spectroscopy laboratory course. The…

  9. The structural, magnetic and microwave properties of spherical and flake shaped carbonyl iron particles as thin multilayer microwave absorbers

    Science.gov (United States)

    Khani, Omid; Shoushtari, Morteza Zargar; Ackland, Karl; Stamenov, Plamen

    2017-04-01

    An increase in microwave permeability is a prerequisite for reducing the thickness of radar absorber coatings. The aim of this paper is to increase the magnetic loss of commercial carbonyl iron particles for fabricating wideband microwave absorbers with a multilayer structure. For this purpose, carbonyl iron particles were milled and their static and dynamic magnetic properties were studied before and after milling. A distinct morphological change from spherical to flake-like particles is measured with increased milling time, whereas no distinct changes in magnetic properties are measured with increased milling time. The imaginary part of the permeability (μ״) of the milled carbonyl iron particles increased from 1.23 to 1.88 and showed a very broad peak over the entire frequency range 1-18 GHz. The experimental results were modeled using the Rousselle effective medium theory (EMT) in the Neo formulation. The theoretical predictions showed good agreement with the experimental results. Two layer absorbers were designed according to the measured microwave parameters and the multilayer design. The results revealed that a thin multilayer with a thickness of 1.75 mm can effectively absorb microwaves in both the entire X and Ku frequency bands. The results suggest that microwave absorbers with excellent absorption properties could be mass-produced, using commercial carbonyl iron particles.

  10. Synthesis and absorbing mechanism of two-layer microwave absorbers containing polycrystalline iron fibers and carbonyl iron

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Qingwei [College of Material Science and Engineering, Taiyuan University of Science and Technology, Taiyuan 030024 (China); Zhang, Mingang, E-mail: qingweiding123@163.com [College of Material Science and Engineering, Taiyuan University of Science and Technology, Taiyuan 030024 (China); Zhang, Cunrui [33th Research Institute of China Electronic Technology Group Corporation, Taiyuan 030006 (China); Qian, Tianwei [College of Environment and Safety, Taiyuan University of Science and Technology, Taiyuan030024 (China)

    2013-04-15

    Polycrystalline iron fibers were fabricated by α-FeOOH fiber precursors. Two-layer microwave absorber had been prepared by as-prepared polycrystalline iron fibers and carbonyl iron. The structure, morphology and properties of the composites were characterized with X-ray diffraction, scanning electron microscope and Network Analyzer. The complex permittivity and reflection loss (dB) of the composites were measured employing vector network analyzer model PNA 3629D vector in the frequency range between 30 and 6000 MHz. The thickness effect of the carbonyl iron layer on the microwave loss properties of the composites was investigated. A possible microwave-absorbing mechanism of polycrystalline iron fibers/carbonyl iron composite was proposed. The polycrystalline iron fibers/carbonyl iron composite can find applications in suppression of electromagnetic interference, and reduction of radar signature. -- Highlights: ► Polycrystalline iron fibers were synthesized by α-FeOOH fiber precursors. ► A polycrystalline iron fiber’s formation mechanism had been proposed. ► Two-layer microwave composite had been prepared. ► The effect of the absorber thickness of on the composites is investigated. ► The composite absorbing mechanism has been proposed.

  11. Antagonism between lipid-derived reactive carbonyls and phenolic compounds in the Strecker degradation of amino acids.

    Science.gov (United States)

    Delgado, Rosa M; Hidalgo, Francisco J; Zamora, Rosario

    2016-03-01

    The Strecker-type degradation of phenylalanine in the presence of 2-pentanal and phenolic compounds was studied to investigate possible interactions that either promote or inhibit the formation of Strecker aldehydes in food products. Phenylacetaldehyde formation was promoted by 2-pentenal and also by o- and p-diphenols, but not by m-diphenols. This is consequence of the ability of phenolic compounds to be converted into reactive carbonyls and produce the Strecker degradation of the amino acid. When 2-pentenal and phenolic compounds were simultaneously present, an antagonism among them was observed. This antagonism is suggested to be a consequence of the ability of phenolic compounds to either react with both 2-pentenal and phenylacetaldehyde, or compete with other carbonyl compounds for the amino acids, a function that is determined by their structure. All these results suggest that carbonyl-phenol reactions may be used to modulate flavor formation produced in food products by lipid-derived reactive carbonyls. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Carbonyl sulfide: an alternate substrate for but not an activator of ribulose-1,5-bisphosphate carboxylase.

    Science.gov (United States)

    Lorimer, G H; Pierce, J

    1989-02-15

    Carbonyl sulfide, a competitive inhibitor of ribulose-bisphosphate carboxylase with respect to CO2 (Laing, W. A., and Christeller, J. T. (1980) Arch. Biochem. Biophys. 202, 592-600), is an alternate substrate. Thiocarboxylation was monitored by mass spectrometry as the stoichiometric consumption of carbonyl sulfide. The product, 1-thio-3-phosphoglycerate, was identified by 13C NMR and UV absorption spectroscopy and measured by enzymic conversion to thiolactate, coupled to the oxidation of NADH. The expected stoichiometry of thiocarboxylation was confirmed. The maximal rates of thiocarboxylation for the spinach and Rhodospirillum rubrum enzymes were close to the maximal rates of carboxylation for these two enzymes. Both enzymes favored CO2 over carbonyl sulfide (with Mg2+ as metal ion) by a factor of about 110. Thiocarboxylation could only be demonstrated with enzymes carbamylated with CO2. Incubation of the carbamylated E.ACO2.Mg complex with excess carbonyl sulfide caused the displacement of the activator carbamate. The thiocarbamylated enzyme was catalytically incompetent and did not form a stable quaternary complex with 2'-carboxyarabinitol bisphosphate. Incubation of the thiocarbamylated enzyme with excess CO2 resulted in the displacement of the thiocarbamate, the re-formation of the carbamylated E.ACO2.Mg complex and the restoration of catalytic competence. Computergraphic simulation of the thiocarbamylated quaternary complex indicated unfavorable van der Waals interactions associated with the thiocarbamate.

  13. Molecular recognition of carbonyl compounds by uranyl-salophen based neutral receptors driven by Van der Waals forces

    NARCIS (Netherlands)

    van Axel castelli, V.; van Axel Castelli, Valeria; Dalla Cort, Antonella; Mandolini, Luigi; Pinto, Valentina; Reinhoudt, David; Ribaudo, Fabrizio; Sanna, Cecilia; Schiaffino, Luca; Ruel, Bianca H.M.

    2002-01-01

    The complexation of the salophen-uranyl metallocleft 2 and of its half-cleft analogue 3 with enones and other carbonyl compounds was assessed in chloroform by UV-Vis titration and, occasionally, by FT-IR measurements. Complexes with receptors 2 and 3 are in all cases more stable than those with the

  14. Engineered Trx2p industrial yeast strain protects glycolysis and fermentation proteins from oxidative carbonylation during biomass propagation

    OpenAIRE

    Gómez-Pastor Rocío; Pérez-Torrado Roberto; Cabiscol Elisa; Ros Joaquim; Matallana Emilia

    2012-01-01

    Background: In the yeast biomass production process, protein carbonylation has severe adverse effects since it diminishes biomass yield and profitability of industrial production plants. However, this significant detriment of yeast performance can be alleviated by increasing thioredoxins levels. Thioredoxins are important antioxidant defenses implicated in many functions in cells, and their primordial functions include scavenging of reactive oxygen species that produce dramatic and irrever...

  15. Double Conjugate Addition of Dithiols to Propargylic Carbonyl Systems To Generate Protected 1,3-Dicarbonyl Compounds

    NARCIS (Netherlands)

    Sneddon, Helen F.; Heuvel, Alexandra van den; Hirsch, Anna K.H.; Booth, Richard A.; Shaw, David M.; Gaunt, Matthew J.; Ley, Steven V.

    2006-01-01

    The work describes the efficient double conjugate addition of ethane and propane dithiols in the presence of sodium methoxide to a wide variety of propargylic carbonyl containing compounds. The products of these reactions are differentiated, 1,3-dicarbonyl systems useful for various synthesis

  16. Highly selective detection of carbon monoxide in living cells by palladacycle carbonylation-based surface enhanced Raman spectroscopy nanosensors.

    Science.gov (United States)

    Cao, Yue; Li, Da-Wei; Zhao, Li-Jun; Liu, Xiao-Yuan; Cao, Xiao-Ming; Long, Yi-Tao

    2015-10-06

    A novel nanosensor was explored for the highly selective detection of intracellular carbon monoxide (CO) by surface enhanced Raman spectroscopy (SERS) on the basis of palladacycle carbonylation. By assembling new synthesized palladacycles (PC) on the surface of gold nanoparticles (AuNPs), SERS nanosensors (AuNP/PC) were prepared with good SERS activity and reactivity with CO. When the AuNP/PC nanosensors were incubated with a CO-containing system, carbonylation of the PC assembled on AuNPs was initiated, and the corresponding SERS spectra of AuNP/PC changed significantly, which allowed the carbonylation reaction to be directly observed in situ. Upon SERS observation of CO-dependent carbonylation, this SERS nanosensor was used for the detection of CO under physiological conditions. Moreover, benefiting from the specificity of the reaction coupled with the fingerprinting feature of SERS, the developed nanosensor demonstrated high selectivity over other biologically relevant species. In vivo studies further indicated that CO in normal human liver cells and HeLa cells at concentrations as low as 0.5 μM were successfully detected with the proposed SERS strategy, demonstrating its great promise for the analytical requirements in studies of physiopathological events involved with CO.

  17. Structure-activity relationship for the estimation of OH-oxidation rate constants of carbonyl compounds in the aqueous phase

    Science.gov (United States)

    Doussin, J.-F.; Monod, A.

    2013-12-01

    In the atmosphere, one important class of reactions occurs in the aqueous phase in which organic compounds are known to undergo oxidation towards a number of radicals, among which OH radicals are the most reactive oxidants. In 2008, Monod and Doussin have proposed a new structure-activity relationship (SAR) to calculate OH-oxidation rate constants in the aqueous phase. This estimation method is based on the group-additivity principle and was until now limited to alkanes, alcohols, acids, bases and related polyfunctional compounds. In this work, the initial SAR is extended to carbonyl compounds, including aldehydes, ketones, dicarbonyls, hydroxy carbonyls, acidic carbonyls, their conjugated bases, and the hydrated form of all these compounds. To do so, only five descriptors have been added and none of the previously attributed descriptors were modified. This extension leads now to a SAR which is based on a database of 102 distinct compounds for which 252 experimental kinetic rate constants have been gathered and reviewed. The efficiency of this updated SAR is such that 58% of the rate constants could be calculated within ±20% of the experimental data and 76% within ±40% (respectively 41 and 72% for the carbonyl compounds alone).

  18. Carbonyl sulfide (COS) as a tracer to constrain surface carbon fluxes

    Science.gov (United States)

    Yakir, Dan; Berkelhammer, Max; Miller, John; Montzka, Steve; Chen, Huilin

    2014-05-01

    provide additional constraints on the differential responses of photosynthesis and respiration, such as associated with C3 and C4 vegetation. Developing the use of COS as a powerful tracer of photosynthetic CO2 fluxes at all scales can help improve prediction of future responses of the terrestrial biosphere to changing environmental conditions. Key words Carbonyl sulfide, COS, Carbonic anhydrase, CA, ecosystem respiration, GPP, Biosphere-atmosphere interactions, soil COS uptake. References Asaf D, Rotenberg E, Tatarinov T, Dicken U, Montzka SA & Yakir D (2013) Ecosystem photosynthesis inferred from carbonyl sulfide flux measurements. Nature GeoScience, 6, 186-190; DOI: 10.1038/NGEO1730 Berry J, Wolf A, Campbell E, Baker I, Blake N, Blake D, Denning AS, Kawa SR, Montzka SA, Seibt UY, Stimler K, Yakir D Zhu Z (2013) A coupled model of the global cycles of carbonyl sulfide and CO2: A possible new window on the carbon cycle. J. Geophys. Res.: Biogeochem. 118, doi 10.1002/jgrg.20068, 2013 Stimler K, Berry JA, Montzka S, Yakir D (2011) Association between COS uptake and 18D during gas exchange in C3 and C4 leaves. Plant Physiol. Doi 10.1104/pp.111.176578

  19. Enantioselective Iridium Catalyzed Carbonyl Allylation from the Alcohol or Aldehyde Oxidation Level via Transfer Hydrogenative Coupling of Allyl Acetate: Departure from Chirally Modified Allyl Metal Reagents in Carbonyl Addition

    Science.gov (United States)

    Kim, In Su; Ngai, Ming-Yu; Krische, Michael J.

    2010-01-01

    Under the conditions of transfer hydrogenation employing an iridium catalyst generated in situ from [Ir(cod)Cl]2, the chiral phosphine ligands (R)-BINAP or (R)-Cl,MeO-BIPHEP and m-nitrobenzoic acid, allyl acetate couples to allylic alcohols 1a-1c, aliphatic alcohols 1d-1l and benzylic alcohols 1m-1u to furnish products of carbonyl allylation 3a-3u with exceptional levels of asymmetric induction. The very same set of optically enriched carbonyl allylation products 3a-3u are accessible from enals 2a-2c, aliphatic aldehydes 2d-2l and aryl aldehydes 2m-2u, using iridium catalysts ligated by (-)-TMBTP or (R)-Cl,MeO-BIPHEP under identical conditions, but employing isopropanol as a hydrogen donor. As corroborated by single crystal X-ray diffraction, the active catalyst is the cyclometallated complex V, which arises upon ortho-C-H insertion of iridium onto m-nitrobenzoic acid. The results of isotopic labeling are consistent with intervention of symmetric iridium π-allylationl intermediates or rapid interconversion of σ-allyl haptomers through the agency of a symmetric π-allyl. Competition experiments demonstrate rapid and reversible hydrogenation-dehydrogenation of the carbonyl partner in advance of C-C coupling. The coupling products, which are homoallylic alcohols, experience very little erosion of optical purity by way of redox equilibration under the coupling conditions, although isopropanol, a secondary alcohol, may serve as terminal reductant. A plausible catalytic mechanism accounting for these observations is proposed, along with a stereochemical model that accounts for the observed sense of absolute stereoinduction. This protocol for asymmetric carbonyl allylation transcends the barriers imposed by oxidation level and the use of preformed allyl-metal reagents. PMID:18841896

  20. Enantioselective iridium-catalyzed carbonyl allylation from the alcohol or aldehyde oxidation level via transfer hydrogenative coupling of allyl acetate: departure from chirally modified allyl metal reagents in carbonyl addition.

    Science.gov (United States)

    Kim, In Su; Ngai, Ming-Yu; Krische, Michael J

    2008-11-05

    Under the conditions of transfer hydrogenation employing an iridium catalyst generated in situ from [Ir(cod)Cl]2, chiral phosphine ligand (R)-BINAP or (R)-Cl,MeO-BIPHEP, and m-nitrobenzoic acid, allyl acetate couples to allylic alcohols 1a-c, aliphatic alcohols 1d-l, and benzylic alcohols 1m-u to furnish products of carbonyl allylation 3a-u with exceptional levels of asymmetric induction. The very same set of optically enriched carbonyl allylation products 3a-u are accessible from enals 2a-c, aliphatic aldehydes 2d-l, and aryl aldehydes 2m-u, using iridium catalysts ligated by (-)-TMBTP or (R)-Cl,MeO-BIPHEP under identical conditions, but employing isopropanol as a hydrogen donor. A catalytically active cyclometallated complex V, which arises upon ortho-C-H insertion of iridium onto m-nitrobenzoic acid, was characterized by single-crystal X-ray diffraction. The results of isotopic labeling are consistent with intervention of symmetric iridium pi-allyl intermediates or rapid interconversion of sigma-allyl haptomers through the agency of a symmetric pi-allyl. Competition experiments demonstrate rapid and reversible hydrogenation-dehydrogenation of the carbonyl partner in advance of C-C coupling. However, the coupling products, which are homoallylic alcohols, experience very little erosion of optical purity by way of redox equilibration under the coupling conditions, although isopropanol, a secondary alcohol, may serve as terminal reductant. A plausible catalytic mechanism accounting for these observations is proposed, along with a stereochemical model that accounts for the observed sense of absolute stereoinduction. This protocol for asymmetric carbonyl allylation transcends the barriers imposed by oxidation level and the use of preformed allyl metal reagents.

  1. Synthesis, characterization and magnetorheological properties of carbonyl iron suspension with superparamagnetic nanoparticles as an additive

    Science.gov (United States)

    Asma' Nikmat Leong, Siti; Mohd Samin, Pakharuddin; Idris, Ani; Amri Mazlan, Saiful; Rahman, Azura Hanis A.

    2016-02-01

    Magnetorheological (MR) fluids are suspensions of micron-sized particles dispersed in carrier fluid. Due to high density magnetic particles, MR fluids are facing the problem with the instability of the suspension caused by high settling rate. Recently, researches have been conducted on the advantages of using the mixture of magnetic nanoparticles and microparticles, called bidisperse MR fluids. However, even though the sedimentation stability is improved, there is a reduction in dynamic yield stress when the nanoparticle is introduced. In this work, the investigation of magnetic iron nanoparticles (γ-Fe2O3) as an additive to magnetic carbonyl iron (CI) suspension has been proposed so as to improve the sedimentation stability and redispersibility, but at the same time enhance the MR performance. The results indicated that the addition of nanoparticles reduced the sedimentation rate, improved redispersibility and enhanced the rheological performance of MR fluids as the particle fill the voids between the microparticles and strengthened the interparticle chains contributing to well-arranged particle structures.

  2. Exchange of carbonyl sulfide (COS between the atmosphere and various soils in China

    Directory of Open Access Journals (Sweden)

    J. Liu

    2010-02-01

    Full Text Available Using a dynamic enclosure, the exchange rates of carbonyl sulfide (COS between the atmosphere and 18 soils from 12 provinces in China were investigated. The emission or uptake of COS from the soils was highly dependent on the soil type, soil temperature, soil moisture, and atmospheric COS mixing ratio. In general, with the only exception being paddy soils, the soils in this investigation acted as sinks for atmospheric COS under wide ranges of soil temperature and soil moisture. Two intensively investigated wheat soils and one forest soil had optimal soil temperatures for COS uptake of around 15 °C, and the optimal soil water content varied from 13% to 58%. COS emission rates from the two paddy soils increased exponentially with increment of the soil temperature, and decreased with increasing the soil water content. However, negligible emission was found when the paddy soils were under waterlogging status. The observed compensation points for various soils were different and increased significantly with soil temperature. The laboratory simulation agreed with the preliminary field measurements for the paddy soil in Jiaxing, Zhejiang province.

  3. Understanding fog-plant interactions at the ecosystem scale using atmospheric carbonyl sulfide

    Science.gov (United States)

    Campbell, J. E.; Whelan, M.; Stinecipher, J.; Zumkehr, A. L.; Berry, J. A.; Dawson, T. E.; Seibt, U.; Hilton, T. W.; Kulkarni, S.; Commane, R.; Angevine, W. M.; Lu, Y.; Herndon, S. C.; Zahniser, M. S.

    2015-12-01

    Ecosystem metabolism is thought to have powerful feedbacks with the climate system as well as direct impacts on individual taxa that rely on ecosystems for food, water, and shelter. Despite the importance of an ecosystem level understanding, climate change impacts on whole ecosystems remains highly uncertain. In particular, coastal fog-dominated regions are a blind spot for whole ecosystem measurements of the land-air-sea exchange of carbon, water, and energy. To address this critical knowledge gap, our inter-displicary team from the University of California's new Institute for the Study of Ecological Effects of Climate Impacts (ISEECI) has launched a next-generation monitoring program along a gradient of UC Natural Reserve System (NRS) sites. We leverage recent breakthroughs in atmospheric spectroscopy and mechanistic ecosystem models of carbonyl sulfide that provide an unprecedented opportunity to explore the sustainability of coastal systems. Here we present our next-generation monitoring and regional analysis across a North/South transect of UC-NRS sites that has the potential to provide a new window into fog-dominated ecosystems, both currently and under climate change scenarios.

  4. Colour removal and carbonyl by-production in high dose ozonation for effluent polishing.

    Science.gov (United States)

    Mezzanotte, V; Fornaroli, R; Canobbio, S; Zoia, L; Orlandi, M

    2013-04-01

    Experimental tests have been conducted to investigate the efficiency and the by-product generation of high dose ozonation (10-60 mg O3 L(-1)) for complete colour removal from a treated effluent with an important component of textile dyeing wastewater. The effluent is discharged into an effluent-dominated stream where no dilution takes place, and, thus, the quality requirement for the effluents is particularly strict. 30, 60 and 90 min contact times were adopted. Colour was measured as absorbance at 426, 558 and 660 nm wavelengths. pH was monitored throughout the experiments. The experimental work showed that at 50 mg L(-1) colour removal was complete and at 60 mg O3 L(-1) the final aldehyde concentration ranged between 0.72 and 1.02 mg L(-1). Glyoxal and methylglyoxal concentrations were directly related to colour removal, whereas formaldehyde, acetaldehyde, acetone and acrolein were not. Thus, the extent of colour removal can be used to predict the increase in glyoxal and methylglyoxal concentrations. As colour removal can be assessed by a simple absorbance measurement, in contrast to the analysis of specific carbonyl compounds, which is much longer and complex, the possibility of using colour removal as an indicator for predicting the toxic potential of ozone by-products for textile effluents is of great value. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. Influence of composition of carbonyl iron particles on dynamic mechanical properties of magnetorheological elastomers

    Science.gov (United States)

    Yu, Miao; Ju, Benxiang; Fu, Jie; Liu, Xueqin; Yang, Qi

    2012-07-01

    Magnetorheological elastomers (MRE) are known as smart materials. However, the magnetorheological (MR) effect of MRE is not high enough at present, which limits its engineering applications. Prior studies have shown that magneto-induced shear storage modulus and MR effect were mainly determined by the performance of the ferromagnetic particles. In this paper, MRE samples were prepared by carbonyl iron particles (CIP) of different compositions based on silicon rubber under external magnetic field. Their microstructures were observed using an optical digital microscope and a scanning electron microscope. The dynamic mechanical properties of MRE samples were measured using a modified dynamic mechanical analyzer under varying magnetic field strength and frequency. The results show that the carbon content of CIP have a greater impact on the dynamic mechanical properties of MRE. The magneto-induced shear storage modulus and MR effect can be increased by selecting CIP of low carbon content. In addition, the damping property is also significantly influenced by the carbon content of the CIP. This study is expected to provide guidance for fabrication of high performance MRE.

  6. Atmospheric measurements of carbonyl sulfide, dimethyl sulfide, and carbon disulfide using the electron capture sulfur detector

    Science.gov (United States)

    Johnson, James E.; Bates, Timothy S.

    1993-01-01

    Measurements of atmospheric dimethyl sulfide (DMS), carbonyl sulfide (COS), and carbon disulfide (CS2) were conducted over the Atlantic Ocean on board the NASA Electra aircraft during the Chemical Instrumentation Test and Evaluation (CITE 3) project using the electron capture sulfur detector (ECD-S). The system employed cryogenic preconcentration of air samples, gas chromatographic separation, catalytic fluorination, and electron capture detection. Samples collected for DMS analysis were scrubbed of oxidants with NaOH impregnated glass fiber filters to preconcentration. The detection limits (DL) of the system for COS, DMS, and CS2 were 5, 5, and 2 ppt, respectively. COS concentrations ranged from 404 to 603 ppt with a mean of 489 ppt for measurements over the North Atlantic Ocean (31 deg N to 41 deg N), and from 395 to 437 ppt with a mean of 419 ppt for measurements over the Tropical Atlantic Ocean (11 deg S to 2 deg N). DMS concentrations in the lower marine boundary layer, below 600-m altitude, ranged from below DL to 150 ppt from flights over the North Atlantic, and from 9 to 104 ppt over the Tropical Atlantic. CS2 concentrations ranged from below DL to 29 ppt over the North Atlantic. Almost all CS2 measurements over the Tropical Atlantic were below DL.

  7. Catalytic Transfer Hydrogenation of Biomass-Derived Carbonyls over Hafnium-Based Metal-Organic Frameworks.

    Science.gov (United States)

    Corma, Avelino; García-García, Pilar; Rojas-Buzo, Sergio

    2017-11-15

    A series of highly crystalline, porous, hafnium-based metal-organic frameworks (MOFs) have shown to catalyze the transfer hydrogenation reaction of levulinic ester to produce γ-valerolactone using isopropanol as hydrogen donor and the results are compared with the zirconium-based counterparts. The role of the metal center in Hf-MOFs has been identified and reaction parameters optimized. NMR studies with isotopically labeled isopropanol evidences that the transfer hydrogenation occurs via a direct intermolecular hydrogen transfer route. The catalyst, Hf-MOF-808, can be recycled several times with only a minor decrease in catalytic activity. Generality of the procedure was shown by accomplishing the transformation with aldehydes, ketones and α,β-unsaturated carbonyl compounds. The combination of Hf-MOF-808 with the Brønsted acidic Al-Beta zeolite gives the four-step one-pot transformation of furfural to γ-valerolactone in good yield of 72%. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Zr-Based MOF-808 as Meerwein–Ponndorf–Verley Reduction Catalyst for Challenging Carbonyl Compounds

    Directory of Open Access Journals (Sweden)

    Eva Plessers

    2016-07-01

    Full Text Available In the fine chemical industry, transfer hydrogenation of carbonyl compounds is an important route to selectively form the corresponding allyl alcohol. The Meerwein–Ponndorf–Verley reduction (MPV is catalyzed by a Lewis acid catalyst and easily oxidizable alcohols serve as hydrogen donor. We successfully used the Zr-based metal-organic framework (MOF MOF-808-P as MPV-catalyst with isopropyl alcohol as solvent and hydride donor. After only 2 h, 99% yield of cinnamyl alcohol was obtained. The highly active MOF-808-P is also a good catalyst for the selective reduction of more challenging substrates such as R-carvone and β-ionone. Two strategies were successfully used to shift the equilibrium towards the desired allylic alcohol products: (1 evaporation of formed acetone and (2 the use of the more strongly reducing 1-indanol. Carveol yield was increased to >70%. These results highlight the great potential of this recently discovered Zr-MOF as a chemically and thermally stable catalyst.

  9. An oxidoreductase from 'Alphonso' mango catalyzing biosynthesis of furaneol and reduction of reactive carbonyls.

    Science.gov (United States)

    Kulkarni, Ram; Chidley, Hemangi; Deshpande, Ashish; Schmidt, Axel; Pujari, Keshav; Giri, Ashok; Gershenzon, Jonathan; Gupta, Vidya

    2013-01-01

    Two furanones, furaneol (4-hydroxy-2,5-dimethyl-3(2H)-furanone) and mesifuran (2,5-dimethyl-4-methoxy-3(2H)-furanone), are important constituents of flavor of the Alphonso cultivar of mango (Mangifera indica). To get insights into the biosynthesis of these furanones, we isolated an enone oxidoreductase gene from the Alphonso mango. It has high sequence similarity to an alkenal/one oxidoreductase from cucumber (79% identity) and enone oxidoreductases from tomato (73% identity) and strawberry (72% identity). The complete open reading frame was expressed in E. coli and the (his)6-tagged recombinant protein was purified by affinity chromatography. The purified protein assayed with NADH as a reducing agent converted D-fructose-1,6-diphosphate into furaneol, the immediate precursor of mesifuran. The enzyme was also able to convert two highly reactive carbonyls, 3-buten-2-one and 1-penten-3-one, produced by lipid peroxidation in plants, into their saturated derivatives. Expression profiling in various ripening stages of Alphonso fruits depicted an expression maxima at 10 days after harvest stage, shortly before the appearance of the maximum amount of furanones (completely ripe stage, 15 days after harvest). Although no furanones were detected at the 0 day after harvest stage, significant expression of this gene was detected in the fruits at this stage. Overall, the results suggest that this oxidoreductase plays important roles in Alphonso mango fruits.

  10. Affinity chromatographic selection of carbonylated proteins followed by identification of oxidation sites using tandem mass spectrometry.

    Science.gov (United States)

    Mirzaei, Hamid; Regnier, Fred

    2005-04-15

    It has been shown that oxidatively modified forms of proteins accumulate during oxidative stress, aging, and in some age-related diseases. One of the unique features of a wide variety of routes by which proteins are oxidized is the generation of carbonyl groups. This paper reports a method for the isolation of oxidized proteins, which involves (1) biotinylation of oxidized proteins with biotin hydrazide and (2) affinity enrichment using monomeric avidin affinity chromatography columns. The selectivity of the method was validated by adding in vitro oxidized biotinylated BSA to a yeast lysate and showing that the predominant protein recovered was BSA. This method was applied to the question of whether large doses of 2-nitropropane produce oxidized proteins. A study of rat liver homogenates showed that animals dosed with 2-nitropropane produced 17 times more oxidized protein than controls in 6 h. Tryptic digestion of these oxidized proteins followed by reversed-phase chromatography and tandem mass spectrometry led to the identification of 14 peptides and their parent proteins. Nine of the 14 identified peptides were found to carry 1 or 2 oxidation sites and 5 of the 9 peptides were biotinylated. The significance of this affinity method is that it allows the isolation of oxidized proteins from the rest of the proteome and facilitates their identification. In some cases, it is even possible to identify the site of oxidation.

  11. A glutathione-based system for defense against carbonyl stress in Haemophilus influenzae

    Directory of Open Access Journals (Sweden)

    Kidd Stephen P

    2012-07-01

    Full Text Available Abstract Background adhC from Haemophilus influenzae encodes a glutathione-dependent alcohol dehydrogenase that has previously been shown to be required for protection against killing by S-nitrosoglutathione (GSNO. This group of enzymes is known in other systems to be able to utilize substrates that form adducts with glutathione, such as aldehydes. Results Here, we show that expression of adhC is maximally induced under conditions of high oxygen tension as well as specifically with glucose as a carbon source. adhC could also be induced in response to formaldehyde but not GSNO. An adhC mutant was more susceptible than wild-type Haemophilus influenzae Rd KW20 to killing by various short chain aliphatic aldehydes, all of which can be generated endogenously during cell metabolism but are also produced by the host as part of the innate immune response. Conclusions These results indicate that AdhC plays a role in defense against endogenously generated reactive carbonyl electrophiles in Haemophilus influenzae and may also play a role in defense against the host innate immune system.

  12. Dynamic nuclear polarization of carbonyl and methyl 13C spins in acetate using trityl OX063

    Science.gov (United States)

    Niedbalski, Peter; Parish, Christopher; Lumata, Lloyd

    2015-03-01

    Hyperpolarization via dissolution dynamic nuclear polarization (DNP) is a physics technique that amplifies the magnetic resonance signals by several thousand-fold for biomedical NMR spectroscopy and imaging (MRI). Herein we have investigated the effect of carbon-13 isotopic location on the DNP of acetate (one of the biomolecules commonly used for hyperpolarization) at 3.35 T and 1.4 K using a narrow ESR linewidth free radical trityl OX063. We have found that the carbonyl 13C spins yielded about twice the polarization produced in methyl 13C spins. Deuteration of the methyl group, beneficial in the liquid-state, did not produce an improvement in the polarization level at cryogenic conditions. Concurrently, the solid-state nuclear relaxation of these samples correlate with the polarization levels achieved. These results suggest that the location of the 13C isotopic labeling in acetate has a direct impact on the solid-state polarization achieved and is mainly governed by the nuclear relaxation leakage factor.

  13. Seasonal carbon fluxes for an old-growth temperate forest inferred from carbonyl sulphide

    Science.gov (United States)

    Rastogi, Bharat; Jiang, Yueyang; Berkelhammer, Maxwell; Wharton, Sonia; Noone, David; Still, Christopher

    2017-04-01

    Characterizing and quantifying the processes that control terrestrial ecosystem exchanges of carbon and water are critical for understanding how forested ecosystems respond to a changing climate. A small but increasing number of studies has identified carbonyl sulfide (OCS) as a potential tracer of canopy photosynthesis and stomatal function. Here we present seasonal fluxes of OCS from a 60m tall old-growth temperate forest. An off-axis integrated cavity output spectroscopy analyzer (Los Gatos Research Inc.) was deployed at the Wind River Experimental Forest in Washington (45.8205°N, 121.9519°W) in 2014 and 2015. GPP (Gross Primary Production) is inferred from OCS fluxes and compared with estimates derived from measurements of NEE (Net Ecosystem Exchange) from eddy flux data as well as GPP predictions using a process based model. Our findings seek to resolve scientific questions regarding ecosystem carbon exchange from tall old growth forests, which have a complicated vertical leaf area structure, high above ground biomass and amount and aerial cover of epiphytic vegetation. Estimates of canopy conductance calculated using tower flux data are also combined with measurements of stable isotopologues of CO2 to infer emergent ecosystem properties such as canopy ci/ca and water use efficiency.

  14. Emissions of polyciclic aromatic hydrocarbons and polyciclic carbonyl biphenils from electric arc furnaces

    Directory of Open Access Journals (Sweden)

    P. Gomes, J. F.

    2008-06-01

    Full Text Available This paper describes work done in order to determine the emissions of highly toxic organic micropollutants from electric arc furnaces used in the production of carbon steel from scrap. The study will be allowing to derive relationships between the levels of airborne micropollutants and the operational parameters of the production process so that an abatement of pollution could be achieved. By using the European standard method CEN 1948 for dioxin like compounds sampling and measurement, it was possible to determine the characteristic fingerprint of micropollutants such as polyciclic aromatic hydrocarbons (PAHs and polycyclic carbonyl biphenils (PCBs emitted by this particular stationary source.

    Este artículo contiene resultados del trabajo ejecutado para estudiar la determinación de las emisiones de los micropolutantes orgánicos muy tóxicos que se emiten por los hornos eléctricos de arco utilizados en la producción de acero. Este estudio inicial va a permitir relacionar las concentraciones de polutantes emitidos a la atmósfera con las condiciones de operación del horno eléctrico de arco. Utilizando el método normalizado CEN 1948 para captación y análisis de muestras de compuestos análogos a las dioxinas ha sido posible determinar el perfil característico de los micropolutantes tales como PAHs y PCBs emitidos por esta fuente.

  15. Infrared spectroscopy of carbonyl sulfide inside a pure 3He droplet.

    Science.gov (United States)

    Sartakov, Boris G; Toennies, J Peter; Vilesov, Andrey F

    2012-04-07

    The infrared spectrum of the ν(3) band of an OCS (carbonyl sulfide) molecule embedded inside pure (3)He droplets of about 12 × 10(3) atoms reported in 1998 [S. Grebenev, J. P. Toennies, and A. F. Vilesov, Science 279, 2083 (1998)] is carefully evaluated. The spectrum, which consists of a broad central peak and a distinct shoulder at lower energy, was analyzed by assuming unresolved rotational line structure of either a linear or a symmetric top. In each case the spectrum was fitted using either Lorentzian or Gaussian peak shapes with a preassigned fixed temperature of 0.15 K or a best fit temperature. Many of the fits describe the spectra nearly equally well and indicate broad R(0), R(1), and P(1) peaks but no Q-branch, a moment of inertia which is about a factor six greater than for the free molecule, and a temperature of 0.07 ± 0.06 K which is significantly less than 0.15 K determined for mixed (3)He∕(4)He droplets. The increased moment of inertia is consistent with about 11 attached (3)He atoms which take part in the end-over-end rotations of the chromophore. The large line widths are attributed to creation of particle-hole pair excitations in the fermionic droplets.

  16. The flux of carbonyl sulfide and carbon disulfide between the atmosphere and a spruce forest

    Directory of Open Access Journals (Sweden)

    X. Xu

    2002-01-01

    Full Text Available Turbulent fluxes of carbonyl sulfide (COS and carbon disulfide (CS2 were measured over a spruce forest in Central Germany using the relaxed eddy accumulation (REA technique. A REA sampler was developed and validated using simultaneous measurements of CO2 fluxes by REA and by eddy correlation. REA measurements were conducted during six campaigns covering spring, summer, and fall between 1997 and 1999. Both uptake and emission of COS and CS2 by the forest were observed, with deposition occurring mainly during the sunlit period and emission mainly during the dark period. On the average, however, the forest acts as a sink for both gases. The average fluxes for COS and CS2 are  -93 ± 11.7 pmol m-2 s-1 and  -18 ± 7.6 pmol m-2 s-1, respectively. The fluxes of both gases appear to be correlated to photosynthetically active radiation and to the CO2 and chem{H_2O} fluxes, supporting the idea that the air-vegetation exchange of both gases is controlled by stomata. An uptake ratio COS/CO2 of 10 ± 1.7 pmol m mol-1 has been derived from the regression line for the correlation between the COS and CO2 fluxes. This uptake ratio, if representative for the global terrestrial net primary production, would correspond to a sink of 2.3 ± 0.5 Tg COS yr-1.

  17. Efficient synthesis of a (S)-fluoxetine intermediate using carbonyl reductase coupled with glucose dehydrogenase.

    Science.gov (United States)

    Tang, Yunping; Zhang, Guomei; Wang, Zheng; Liu, Dan; Zhang, Linglu; Zhou, Yafeng; Huang, Ju; Yu, Fangmiao; Yang, Zuisu; Ding, Guofang

    2017-11-01

    (S)-3-chloro-1-phenyl-1-propanol ((S)-CPPO) is an important chiral intermediate predominantly used in the synthesis of the chiral side chain of (S)-fluoxetine. In this study, carbonyl reductase (CBR) from Novosphingobium aromaticivorans was successfully expressed in recombinant E. coli. The enzymatic activity of the recombinant CBR was significantly increased to 1875 U/mL in the fed-batch fermentation in a 10 L fermenter and recombinant CBR was then purified and characterized. By regenerating NADH with glucose dehydrogenase, 100 g/L 3-chloro-1-phenyl-1-propanone (3-CPP) was successfully converted to (S)-CPPO with a conversion of 100% and ee value of 99.6% after 12 h at 30 °C in PBS buffer (pH 7.0), which are the highest reported to date for the bio-production of (S)-CPPO and presented great potential for green production of (S)-CPPO at industrial scale. Copyright © 2017. Published by Elsevier Ltd.

  18. Study of the formation of carbonyl compounds in edible oils and fats by 1H-NMR and FTIR

    Science.gov (United States)

    Moya Moreno, M. C. M.; Mendoza Olivares, D.; Amézquita López, F. J.; Peris Martínez, V.; Bosch Reig, F.

    1999-05-01

    Oils and fats start decomposing from the moment they are isolated from their natural environment. Heating accelerates oxidative rancidity and frying at high temperatures produces thermal degradation with the formation of decomposition products, such as aldehydes, ketones, free acids and hydroxilic compounds that in high levels can be harmful to human health. The decomposition products formed up to 300°C were determined by means of 1H-NMR spectroscopy and an FTIR spectroscopic method was developed for the quantification of carbonyl compounds generated during heating. The results show that there is a formation of carbonyl compounds starting at 150°C and when the sample was heated at 300°C for 40 min, the following contents (expressed as butyraldehyde mass fraction) were found: olive oil 10.5%, sunflower oil 11.3%, corn oil 3.0%, seeds oil (sunflower, safflower and canola seed) 6.6% and lard 3.5%.

  19. Airborne measurements of sulfur dioxide, dimethyl sulfide, carbon disulfide, and carbonyl sulfide by isotope dilution gas chromatography/mass spectrometry

    Science.gov (United States)

    Bandy, Alan R.; Thornton, Donald C.; Driedger, Arthur R., III

    1993-01-01

    A gas chromatograph/mass spectrometer is described for determining atmospheric sulfur dioxide, carbon disulfide, dimethyl sulfide, and carbonyl sulfide from aircraft and ship platforms. Isotopically labelled variants of each analyte were used as internal standards to achieve high precision. The lower limit of detection for each species for an integration time of 3 min was 1 pptv for sulfur dioxide and dimethyl sulfide and 0.2 pptv for carbon disulfide and carbonyl sulfide. All four species were simultaneously determined with a sample frequency of one sample per 6 min or greater. When only one or two species were determined, a frequency of one sample per 4 min was achieved. Because a calibration is included in each sample, no separate calibration sequence was needed. Instrument warmup was only a few minutes. The instrument was very robust in field deployments, requiring little maintenance.

  20. Alkyloxy carbonyl modified hexapeptides as a high affinity compounds for Wnt5A protein in the treatment of psoriasis

    Science.gov (United States)

    Kelotra, Ankit; Gokhale, Sadashiv M; Kelotra, Seema; Mukadam, Vaidehi; Nagwanshi, Komal; Bandaru, Srinivas; Nayarisseri, Anuraj; Bidwai, Anil

    2014-01-01

    Psoriasis is one of the most prevalent chronic inflammatory diseases of the skin. The Wnt pathways have been documented to play essential role in stem cell self-renewal and keratinocyte differentiation in the skin. Antagonizing the Wnt5a protein would emerge as a novel therapeutics in psoriasis treatment. In this view, we have developed and characterized series of compounds by attaching varied tertiary alkyloxy carbonyl groups at the N-terminal end of the hexapeptide (Met-Asp-Gly-Cys-Glu-Leu) bestowed to inhibit Wnt/Ca2+ signaling in psoriasis. Hexapeptide compound with 1,1-diphenylethoxy carbonyl group attached to N-terminal end of hexapeptide demonstrated highest binding affinity amongst all the evaluated compounds. The compound identified in the study can be subjected further for in vitro and in vivo studies for ADMET properties. PMID:25670877

  1. Ligand Influence on Carbonyl Hydroboration Catalysis by Alkali Metal Hydridotriphenylborates [(L)M][HBPh3 ] (M=Li, Na, K).

    Science.gov (United States)

    Osseili, Hassan; Mukherjee, Debabrata; Spaniol, Thomas P; Okuda, Jun

    2017-10-12

    Alkali metal hydridotriphenylborates [(L(1) )M][HBPh3 ] (L(1) =Me6 TREN; M=Li, Na, K) chemoselectively catalyze the hydroboration of carbonyls and CO2 , with lithium being the most active system. A new series of complexes [(L(2) )M][HBPh3 ] [M=Li (1), Na (2), K (3)] featuring the cyclen-derived macrocyclic polyamine Me4 TACD (L(2) ) were synthesized in a "one-pot" fashion and fully characterized including X-ray crystallography. In the crystal, 1-3 exhibit wide variation in metal coordination of the [HBPh3 ](-) anion from lithium to potassium. The structures differ from those in [(L(1) )M][HBPh3 ]. Effects of coordination of L(1) , L(2) , and other N- and O-donor multidentate ligands on [Li(HBPh3 )] were used to rationalize the catalytic activity in carbonyl hydroboration. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Trifluoromethylation-initiated remote cross-coupling of carbonyl compounds to form carbon-heteroatom/carbon bonds.

    Science.gov (United States)

    Huang, Lin; Zheng, Sheng-Cai; Tan, Bin; Liu, Xin-Yuan

    2015-04-27

    By involving the reversal of conventional reactivity expectations without external oxidants, we describe a novel and convenient protocol of remote cross-coupling of carbonyl compounds with a series of common and simple nucleophiles. This cross-coupling is triggered by radical trifluoromethylation of alkenes, thereby achieving highly selective remote difunctionalization of alkenes and α-position of the carbonyl group for facile access to trifluoromethyl α-halo- and α-cyanocarbonyl compounds. The reaction exhibits a broad substrate scope with excellent functionality tolerance and many different types of nucleophiles; further synthetic applicability of the obtained compounds proved to be suitable, thus showing great potential for synthetic utility. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Hafnium trifluoromethanesulfonate (hafnium triflate) as a highly efficient catalyst for chemoselective thioacetalization and transthioacetalization of carbonyl compounds.

    Science.gov (United States)

    Wu, Yan-Chao; Zhu, Jieping

    2008-12-05

    A range of carbonyl compounds including aliphatic and aromatic aldehydes and ketones were converted to the corresponding thioacetals in high yields in the presence of a catalytic amount of hafnium trifluoromethanesulfonate (0.1 mol %, room temperature). The mild conditions tolerated various sensitive functional and protecting groups and were racemization-free when applied to alpha-aminoaldehydes. Transacetalization and chemoselective thioacetalization of aromatic aldehydes in the presence of aliphatic aldehydes and ketones were also documented.

  4. Enhanced anti-Diastereo- and Enantioselectivity in Alcohol Mediated Carbonyl Crotylation Using an Isolable Single Component Iridium Catalyst

    OpenAIRE

    Gao, Xin; Townsend, Ian A.; Krische, Michael J.

    2011-01-01

    The cyclometallated iridium complex (S)-I derived from [Ir(cod)Cl]2, 4-cyano-3-nitrobenzoic acid, allyl acetate and (S)-SEGPHOS is conveniently isolated by precipitation or through conventional silica gel flash chromatography. This single component precatalyst allows alcohol mediated carbonyl crotylations to be performed at significantly lower temperature, resulting in enhanced levels of anti-diastereo- and enantioselectivity. Most significantly, the chromatographically isolated precatalyst (...

  5. Amberlyst-15: An Efficient and reusable heterogeneous catalyst for the synthesis of β-amino carbonyl compounds

    Directory of Open Access Journals (Sweden)

    Pathakota Venkata Ramana

    2015-12-01

    Full Text Available A simple and efficient method has been developed for the synthesis of β-amino carbonyl compounds from aromatic ketones, aldehydes and amines by Mannich reaction in the presence of amberlyst-15 as a reusable heterogeneous catalyst at room temperature under solvent-free conditions. The noteworthy advantages of the present method are short reaction times, good product yields, simple procedures and use of non-toxic catalyst.

  6. Selectively fluorinated cyclohexane building blocks: Derivatives of carbonylated all-cis-3-phenyl-1,2,4,5-tetrafluorocyclohexane

    Directory of Open Access Journals (Sweden)

    Mohammed Salah Ayoup

    2015-12-01

    Full Text Available Palladium catalysed carbonylation reactions using the meta- and para-iodo derivatives of all-cis-3-phenyl-1,2,4,5-tetrafluorocyclohexane (4 are illustrated as the start point for a variety of functional group interconversions. The resultant benzaldehyde and benzoic acids offer novel building blocks for further derivatisation and facilitate the incorporation of the facially polarised all-cis-1,2,4,5-tetrafluorocyclohexane motif into more advanced molecular scaffolds.

  7. Metal-carbonyl organometallic polymers, PFpP, as resists for high-resolution positive and negative electron beam lithography.

    Science.gov (United States)

    Zhang, J; Cao, K; Wang, X S; Cui, B

    2015-12-25

    Metal-containing resists for electron beam lithography (EBL) are attracting attention owing to their high dry etching resistance and possibility for directly patterning metal-containing nanostructures. The newly developed organometallic metal carbonyl polymers, PFpP, can function as EBL resists with strong etching resistance. One significant feature of the PFpP resist is its high resolution. Line arrays with line-widths as narrow as 17 nm have been created. The resist can also be used in positive tone.

  8. Catalytic properties and crystal structure of thermostable NAD(P)H-dependent carbonyl reductase from the hyperthermophilic archaeon Aeropyrum pernix K1.

    Science.gov (United States)

    Fukuda, Yudai; Sakuraba, Haruhiko; Araki, Tomohiro; Ohshima, Toshihisa; Yoneda, Kazunari

    2016-09-01

    A gene encoding NAD(P)H-dependent carbonyl reductase (CR) from the hyperthermophilic archaeon Aeropyrum pernix K1 was overexpressed in Escherichia coli. Its product was effectively purified and characterized. The expressed enzyme was the most thermostable CR found to date; the activity remained at approximately 75% of its activity after incubation for 10min up to 90°C. In addition, A. pernix CR exhibited high stability at a wider range of pH values and longer periods of storage compared with CRs previously identified from other sources. A. pernix CR catalyzed the reduction of various carbonyl compounds including ethyl 4-chloro-3-oxobutanoate and 9,10-phenanthrenequinone, similar to the CR from thyroidectomized (Tx) chicken fatty liver. However, A. pernix CR exhibited significantly higher Km values against several substrates than Tx chicken fatty liver CR. The three-dimensional structure of A. pernix CR was determined using the molecular replacement method at a resolution of 2.09Å, in the presence of NADPH. The overall fold of A. pernix CR showed moderate similarity to that of Tx chicken fatty liver CR; however, A. pernix CR had no active-site lid unlike Tx chicken fatty liver CR. Consequently, the active-site cavity in the A. pernix CR was much more solvent-accessible than that in Tx chicken fatty liver CR. This structural feature may be responsible for the enzyme's lower affinity for several substrates and NADPH. The factors contributing to the much higher thermostability of A. pernix CR were analyzed by comparing its structure with that of Tx chicken fatty liver CR. This comparison showed that extensive formation of the intrasubunit ion pair networks, and the presence of the strong intersubunit interaction, is likely responsible for A. pernix CR thermostability. Site-directed mutagenesis showed that Glu99 plays a major role in the intersubunit interaction. This is the first report regarding the characteristics and three-dimensional structure of

  9. Carbonyl Activation by Borane Lewis Acid Complexation: Transition States of H2Splitting at the Activated Carbonyl Carbon Atom in a Lewis Basic Solvent and the Proton-Transfer Dynamics of the Boroalkoxide Intermediate.

    Science.gov (United States)

    Heshmat, Mojgan; Privalov, Timofei

    2017-07-06

    By using transition-state (TS) calculations, we examined how Lewis acid (LA) complexation activates carbonyl compounds in the context of hydrogenation of carbonyl compounds by H 2 in Lewis basic (ethereal) solvents containing borane LAs of the type (C 6 F 5 ) 3 B. According to our calculations, LA complexation does not activate a ketone sufficiently enough for the direct addition of H 2 to the O=C unsaturated bond; but, calculations indicate a possibly facile heterolytic cleavage of H 2 at the activated and thus sufficiently Lewis acidic carbonyl carbon atom with the assistance of the Lewis basic solvent (i.e., 1,4-dioxane or THF). For the solvent-assisted H 2 splitting at the carbonyl carbon atom of (C 6 F 5 ) 3 B adducts with different ketones, a number of TSs are computed and the obtained results are related to insights from experiment. By using the Born-Oppenheimer molecular dynamics with the DFT for electronic structure calculations, the evolution of the (C 6 F 5 ) 3 B-alkoxide ionic intermediate and the proton transfer to the alkoxide oxygen atom were investigated. The results indicate a plausible hydrogenation mechanism with a LA, that is, (C 6 F 5 ) 3 B, as a catalyst, namely, 1) the step of H 2 cleavage that involves a Lewis basic solvent molecule plus the carbonyl carbon atom of thermodynamically stable and experimentally identifiable (C 6 F 5 ) 3 B-ketone adducts in which (C 6 F 5 ) 3 B is the "Lewis acid promoter", 2) the transfer of the solvent-bound proton to the oxygen atom of the (C 6 F 5 ) 3 B-alkoxide intermediate giving the (C 6 F 5 ) 3 B-alcohol adduct, and 3) the S N 2-style displacement of the alcohol by a ketone or a Lewis basic solvent molecule. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Heterogeneous Epoxide Carbonylation by Cooperative Ion-Pair Catalysis in Co(CO)4--Incorporated Cr-MIL-101.

    Science.gov (United States)

    Park, Hoyoung D; Dincă, Mircea; Román-Leshkov, Yuriy

    2017-05-24

    Despite the commercial desirability of epoxide carbonylation to β-lactones, the reliance of this process on homogeneous catalysts makes its industrial application challenging. Here we report the preparation and use of a Co(CO) 4 - -incorporated Cr-MIL-101 (Co(CO) 4 ⊂Cr-MIL-101, Cr-MIL-101 = Cr 3 O(BDC) 3 F, H 2 BDC = 1,4-benzenedicarboxylic acid) heterogeneous catalyst for the ring-expansion carbonylation of epoxides, whose activity, selectivity, and substrate scope are on par with those of the reported homogeneous catalysts. We ascribe the observed performance to the unique cooperativity between the postsynthetically introduced Co(CO) 4 - and the site-isolated Lewis acidic Cr(III) centers in the metal-organic framework (MOF). The heterogeneous nature of Co(CO) 4 ⊂Cr-MIL-101 allows the first demonstration of gas-phase continuous-flow production of β-lactones from epoxides, attesting to the potential applicability of the heterogeneous epoxide carbonylation strategy.

  11. Determination of protein carbonyls in plasma, cell extracts, tissue homogenates, isolated proteins: Focus on sample preparation and derivatization conditions

    Directory of Open Access Journals (Sweden)

    Daniela Weber

    2015-08-01

    Full Text Available Protein oxidation is involved in regulatory physiological events as well as in damage to tissues and is thought to play a key role in the pathophysiology of diseases and in the aging process. Protein-bound carbonyls represent a marker of global protein oxidation, as they are generated by multiple different reactive oxygen species in blood, tissues and cells. Sample preparation and stabilization are key steps in the accurate quantification of oxidation-related products and examination of physiological/pathological processes. This review therefore focuses on the sample preparation processes used in the most relevant methods to detect protein carbonyls after derivatization with 2,4-dinitrophenylhydrazine with an emphasis on measurement in plasma, cells, organ homogenates, isolated proteins and organelles. Sample preparation, derivatization conditions and protein handling are presented for the spectrophotometric and HPLC method as well as for immunoblotting and ELISA. An extensive overview covering these methods in previously published articles is given for researchers who plan to measure protein carbonyls in different samples.

  12. Enantioselective Carbonyl Reverse Prenylation from the Alcohol or Aldehyde Oxidation Level Employing 1,1-Dimethylallene as the Prenyl Donor

    Science.gov (United States)

    Han, Soo Bong; Kim, In Su; Han, Hoon; Krische, Michael J.

    2010-01-01

    Enantioselective transfer hydrogenation of 1,1-dimethylallene 1a in the presence of aromatic, α,β-unsaturated or aliphatic aldehydes 2a-2i mediated by isopropanol and employing a cyclometallated iridium C,O-benzoate derived from allyl acetate, m-nitrobenzoic acid and (S)-SEGPHOS delivers products of reverse prenylation 4a-4i in good to excellent isolated yields (65-96%) and enantioselectivities (87-93% ee). In the absence of isopropanol, enantioselective carbonyl reverse prenylation is achieved directly from the alcohol oxidation level to furnish an equivalent set of adducts 4a-4i in good to excellent isolated yields (68-94%) and enantioselectivities (86-91% ee). Competition and isotopic labeling experiments suggest rapid alcohol-aldehyde redox equilibration in advance of carbonyl addition, and capture of the kinetically formed π-allyl complex at a rate faster than reversible β-hydride elimination-hydrometallation. This protocol represents an alternative to the use of allylboron reagents in enantioselective carbonyl reverse prenylation and represents the first use of allenes in enantioselective C-C bond forming transfer hydrogenation. PMID:19453190

  13. Determination of protein carbonyls in plasma, cell extracts, tissue homogenates, isolated proteins: Focus on sample preparation and derivatization conditions.

    Science.gov (United States)

    Weber, Daniela; Davies, Michael J; Grune, Tilman

    2015-08-01

    Protein oxidation is involved in regulatory physiological events as well as in damage to tissues and is thought to play a key role in the pathophysiology of diseases and in the aging process. Protein-bound carbonyls represent a marker of global protein oxidation, as they are generated by multiple different reactive oxygen species in blood, tissues and cells. Sample preparation and stabilization are key steps in the accurate quantification of oxidation-related products and examination of physiological/pathological processes. This review therefore focuses on the sample preparation processes used in the most relevant methods to detect protein carbonyls after derivatization with 2,4-dinitrophenylhydrazine with an emphasis on measurement in plasma, cells, organ homogenates, isolated proteins and organelles. Sample preparation, derivatization conditions and protein handling are presented for the spectrophotometric and HPLC method as well as for immunoblotting and ELISA. An extensive overview covering these methods in previously published articles is given for researchers who plan to measure protein carbonyls in different samples. © 2015 Published by Elsevier Ltd.

  14. Platinum catalysed 3,4- and 1,4-diboration of alpha,beta-unsaturated carbonyl compounds using bis-pinacolatodiboron.

    Science.gov (United States)

    Bell, Nathan J; Cox, Andrew J; Cameron, Neil R; Evans, John S O; Marder, Todd B; Duin, Marcel A; Elsevier, Cornelis J; Baucherel, Xavier; Tulloch, Arran A D; Tooze, Robert P

    2004-08-21

    Bis-pinacolatodiboron reacts with [small alpha],[small beta]-unsaturated carbonyl compounds to give 1,4- and unprecedented 3,4-additions in the presence of a second generation Pt(0) catalyst at ambient temperature.

  15. Characterization of odorous compounds (VOC and carbonyl compounds) in the ambient air of Yeosu and Gwangyang, large industrial areas of South Korea

    National Research Council Canada - National Science Library

    Seo, Young-Kyo; Suvarapu, Lakshmi Narayana; Baek, Sung-Ok

    2014-01-01

    ... them. This study measured the odorous volatile organic compounds (VOC) and carbonyl compounds at Yeosu and Gwangyang, two large industrial areas of South Korea, during four seasons of 2008-2009...

  16. Fabrication of Yolk-Shell Cu@C Nanocomposites as High-Performance Catalysts in Oxidative Carbonylation of Methanol to Dimethyl Carbonate

    National Research Council Canada - National Science Library

    Wang, Juan; Hao, Panpan; Shi, Ruina; Yang, Leilei; Liu, Shusen; Zhao, Jinxian; Ren, Jun; Li, Zhong

    2017-01-01

    .... By deliberately creating shell porosity through KOH chemical activation, at an optimized KOH/HCS mass ratio of 1/4, the catalytic performance for the oxidative carbonylation of methanol to dimethyl carbonate (DMC...

  17. Indium-Catalyzed Amide Allylation of N-Carbonyl Imides: Formation of Azaspiro-γ-lactones via Ring Opening-Reclosure.

    Science.gov (United States)

    Sengoku, Tetsuya; Murata, Yusuke; Aso, Yuwa; Kawakami, Ai; Inuzuka, Toshiyasu; Sakamoto, Masami; Takahashi, Masaki; Yoda, Hidemi

    2015-12-04

    A novel and facile synthesis of azaspiro-γ-lactones with a methylene-lactam framework from N-carbonyl imides is described. Mechanistic investigations provide evidence for a two-step reaction process involving ZnCl(2)-promoted addition of β-amido allylindium species followed by an unexpectedly molecular-sieves-mediated ring opening-reclosure concomitantly with the loss of an N-carbonyl unit.

  18. Observations of the uptake of carbonyl sulfide (COS by trees under elevated atmospheric carbon dioxide concentrations

    Directory of Open Access Journals (Sweden)

    L. Sandoval-Soto

    2012-08-01

    Full Text Available Global change forces ecosystems to adapt to elevated atmospheric concentrations of carbon dioxide (CO2. We understand that carbonyl sulfide (COS, a trace gas which is involved in building up the stratospheric sulfate aerosol layer, is taken up by vegetation with the same triad of the enzymes which are metabolizing CO2, i.e. ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco, phosphoenolpyruvate carboxylase (PEP-Co and carbonic anhydrase (CA. Therefore, we discuss a physiological/biochemical acclimation of these enzymes affecting the sink strength of vegetation for COS. We investigated the acclimation of two European tree species, Fagus sylvatica and Quercus ilex, grown inside chambers under elevated CO2, and determined the exchange characteristics and the content of CA after a 1–2 yr period of acclimation from 350 ppm to 800 ppm CO2. We demonstrate that a compensation point, by definition, does not exist. Instead, we propose to discuss a point of uptake affinity (PUA. The results indicate that such a PUA, the CA activity and the deposition velocities may change and may cause a decrease of the COS uptake by plant ecosystems, at least as long as the enzyme acclimation to CO2 is not surpassed by an increase of atmospheric COS. As a consequence, the atmospheric COS level may rise causing an increase of the radiative forcing in the troposphere. However, this increase is counterbalanced by the stronger input of this trace gas into the stratosphere causing a stronger energy reflection by the stratospheric sulfur aerosol into space (Brühl et al., 2012. These data are very preliminary but may trigger a discussion on COS uptake acclimation to foster measurements with modern analytical instruments.

  19. Microwave absorbing property of silicone rubber composites with added carbonyl iron particles and graphite platelet

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Yonggang; Zhang, Deyuan [Bionic and Micro/Nano/Bio-Manufacturing Technology Research Center, School of Mechanical Engineering and Automation, Beihang University, Beijing 100191 (China); Cai, Jun, E-mail: jun_cai@buaa.edu.cn [Bionic and Micro/Nano/Bio-Manufacturing Technology Research Center, School of Mechanical Engineering and Automation, Beihang University, Beijing 100191 (China); Yuan, Liming; Zhang, Wenqiang [Bionic and Micro/Nano/Bio-Manufacturing Technology Research Center, School of Mechanical Engineering and Automation, Beihang University, Beijing 100191 (China)

    2013-02-15

    Silicone rubber composites filled with carbonyl iron particles (CIPs) and graphite platelet (GP) were prepared using non-coating or coating processes. The complex permittivity and permeability of the composites were measured using a vector network analyzer in the frequency range of 1-18 GHz and dc electric conductivity was measured by the standard four-point contact method. The results showed that CIPs/GP composites fabricated in the coating process had the highest permittivity and permeability due to the particle orientation and interactions between the two absorbents. The coating process resulted in a decreased effective eccentricity of the absorbents, and the dc conductivity increased according to Neelakanta's equations. The reflection loss (RL) value showed that the composites had an excellent absorbing property in the L-band, minimum -11.85 dB at 1.5 mm and -15.02 dB at 2 mm. Thus, GP could be an effective additive in preparing thin absorbing composites in the L-band. - Highlights: Black-Right-Pointing-Pointer The added GP increased the permittivity and permeability of composites filled with CIPs. Black-Right-Pointing-Pointer The enhancement was owing to interactions of the two absorbents and the fabrication process. Black-Right-Pointing-Pointer The coating process decreased the effective eccentricity of the particles, and increased the conductivity of the composites. Black-Right-Pointing-Pointer The composites to which CIPs/GP were added in coating process had excellent absorbing properties in the L-band.

  20. The potential of carbonyl sulfide as a proxy for gross primary production at flux tower sites

    Science.gov (United States)

    Blonquist, J. Mark, Jr.

    Seasonal dynamics of atmospheric carbonyl sulfide (OCS) at regional and continental scales and plant OCS exchange at the leaf level have shown a close relationship with those for CO2. CO2 has both sinks and sources within terrestrial ecosystems, but the primary terrestrial exchange for OCS is thought to be leaf uptake, suggesting potential for OCS uptake as a proxy for gross primary production (GPP). The utility of OCS uptake as a GPP proxy in micrometeorological studies of biosphere-atmosphere CO2 exchange was explored by applying theoretical concepts from earlier OCS studies to estimate GPP. Measured net ecosystem exchange (NEE) was partitioned using the ratio of measured vertical mole fraction gradients of OCS and CO2. At the Harvard Forest AmeriFlux site, measured CO2 and OCS vertical gradients were correlated, and were related to NEE and GPP, respectively. Estimates of GPP from OCS-based NEE partitioning were similar to those from established regression techniques, providing evidence that OCS uptake can potentially serve as a GPP proxy. Measured vertical CO 2 mole fraction gradients at five other AmeriFlux sites were used to project anticipated vertical OCS mole fraction gradients to provide indication of potential OCS signal magnitudes at sites where no OCS measurements were made. Projected OCS gradients at sites with short canopies were greater than those in forests, including measured OCS gradients at Harvard Forest, indicating greater potential for OCS uptake as a GPP proxy at these sites. This exploratory study suggests that continued investigation of linkages between OCS and GPP is warranted.

  1. Carbonyl Sulfide Fluxes from a Tall Grass Prairie Ecosystem Through a Growing Season

    Science.gov (United States)

    Alsip, B. M.; Berkelhammer, M. B.; Matamala, R.; Cook, D. R.; Whelan, C.

    2016-12-01

    An ecosystem's carbonyl sulfide (OCS or COS) flux is a powerful proxy for plant-controlled carbon and water exchange. Few studies have applied this approach to grassland ecosystems, which are characterized by complex species distributions that vary temporally. Our results reported here contrast previous work done on OCS fluxes from agricultural and forest ecosystems where climate and phenology shift but species distributions are fixed. A laser absorption spectrometer installed in a temperature-controlled enclosure measured OCS flux data continuously during the entire growing season at the Fermi prairie eddy covariance site in Illinois, USA. Ambient atmospheric concentrations of OCS, carbon monoxide, carbon dioxide (CO2), and water vapor (H2O) were sampled at 1 Hz frequency from four inlets at different heights within and above the vegetation canopy from May to October, 2016. We observed a well-defined seasonal OCS cycle whose trend followed the Northern Hemisphere average. The data also show a strong diel cycle in the above-canopy gradient and absolute concentrations. Nighttime OCS in the canopy periodically dropped below 30 pmol•m-1, which, to our knowledge, are the lowest tropospheric OCS concentrations ever observed. These values were associated with steep OCS gradients above the canopy of -80 pmol•mol-1•m-1. These results highlight significant nighttime plant and soil uptake of OCS. Midday OCS gradients were -8.0 pmol•mol-1•m-1 and variations followed the day-to-day CO2 gradient. This demonstrates the close coupling of OCS and CO2 even as the season and species makeup evolves. Using the flux-gradient approach, we will convert OCS gradients to ecosystem fluxes by deriving the eddy diffusivity from existing eddy covariance data on site. After correcting for OCS and CO2 soil fluxes, we will compare gross primary productivity (GPP) derived from the two approaches, and assess the robustness of OCS to constrain GPP in this ecosystem.

  2. Acrylic acid derivatives of group 8 metal carbonyls: a structural and kinetic study.

    Science.gov (United States)

    Li, Bo; Kyran, Samuel J; Yeung, Andrew D; Bengali, Ashfaq A; Darensbourg, Donald J

    2013-05-06

    The synthesis, spectroscopic, and X-ray structural studies of acrylic acid complexes of iron and ruthenium tetracarbonyls are reported. In addition, the deprotonated η(2)-olefin bound acrylic acid derivative of iron as well as its alkylated species were fully characterized by X-ray crystallography. Kinetic data were determined for the replacement of acrylic acid, acrylate, and methylacrylate for the group 8 metal carbonyls by triphenylphosphine. These processes were found to be first-order in the concentration of metal complex with the rates for dissociative loss of the olefinic ligands from ruthenium being much faster than their iron analogues. However, the ruthenium derivatives afforded formation of primarily mono-phosphine metal tetracarbonyls, whereas the iron complexes led largely to trans-di-phosphine tricarbonyls. This difference in behavior was ascribed to a more stable spin crossover species (3)Fe(CO)4 which undergoes rapid CO loss to afford the bis phosphine derivative. The activation enthalpies for dissociative loss of the deprotonated η(2)-bound acrylic acid ligand were found to be larger than their corresponding values in the protonated derivatives. For example, for dissociative loss of the protonated and deprotonated acrylic acid derivatives of iron(0) the ΔH(‡) values determined were 28.0 ± 1.2 and 34.1 ± 1.5 kcal·mol(-1), respectively. Density functional theory (DFT) computations of the bond dissociation energies (BDEs) in these acrylic acids and closely related complexes were in good agreement with enthalpies of activation for these ligand substitution reactions, supportive of a dissociative mechanism for olefin displacement. Processes related to catalytic production of acrylic acid from CO2 and ethylene are considered.

  3. Carbonyl sulfide exchange in a temperate loblolly pine forest grown under ambient and elevated CO2

    Directory of Open Access Journals (Sweden)

    B. C. Sive

    2010-01-01

    Full Text Available Vegetation, soil and ecosystem level carbonyl sulfide (COS exchange was observed at Duke Forest, a temperate loblolly pine forest, grown under ambient (Ring 1, R1 and elevated (Ring 2, R2 CO2. During calm meteorological conditions, ambient COS mixing ratios at the top of the forest canopy followed a distinct diurnal pattern in both CO2 growth regimes, with maximum COS mixing ratios during the day (R1=380±4 pptv and R2=373±3 pptv, daytime mean ± standard error and minimums at night (R1=340±6 pptv and R2=346±5 pptv, nighttime mean ± standard error reflecting a significant nighttime sink. Nocturnal vegetative uptake (−11 to −21 pmol m−2s−1, negative values indicate uptake from the atmosphere dominated nighttime net ecosystem COS flux estimates (−10 to −30 pmol m−2s−1 in both CO2 regimes. In comparison, soil uptake (−0.8 to −1.7 pmol m−2 s−1 was a minor component of net ecosystem COS flux. In both CO2 regimes, loblolly pine trees exhibited substantial COS consumption overnight (50% of daytime rates that was independent of CO2 assimilation. This suggests current estimates of the global vegetative COS sink, which assume that COS and CO2 are consumed simultaneously, may need to be reevaluated. Ambient COS mixing ratios, species specific diurnal patterns of stomatal conductance, temperature and canopy position were the major factors influencing the vegetative COS flux at the branch level. While variability in branch level vegetative COS consumption measurements in ambient and enhanced CO2 environments could not be attributed to CO2 enrichment effects, estimates of net ecosystem COS flux based on ambient canopy mixing ratio measurements suggest less nighttime uptake of COS in R2, the CO2 enriched environment.

  4. High winter ozone pollution from carbonyl photolysis in an oil and gas basin

    Science.gov (United States)

    Edwards, Peter M.; Brown, Steven S.; Roberts, James M.; Ahmadov, Ravan; Banta, Robert M.; Degouw, Joost A.; Dubé, William P.; Field, Robert A.; Flynn, James H.; Gilman, Jessica B.; Graus, Martin; Helmig, Detlev; Koss, Abigail; Langford, Andrew O.; Lefer, Barry L.; Lerner, Brian M.; Li, Rui; Li, Shao-Meng; McKeen, Stuart A.; Murphy, Shane M.; Parrish, David D.; Senff, Christoph J.; Soltis, Jeffrey; Stutz, Jochen; Sweeney, Colm; Thompson, Chelsea R.; Trainer, Michael K.; Tsai, Catalina; Veres, Patrick R.; Washenfelder, Rebecca A.; Warneke, Carsten; Wild, Robert J.; Young, Cora J.; Yuan, Bin; Zamora, Robert

    2014-10-01

    The United States is now experiencing the most rapid expansion in oil and gas production in four decades, owing in large part to implementation of new extraction technologies such as horizontal drilling combined with hydraulic fracturing. The environmental impacts of this development, from its effect on water quality to the influence of increased methane leakage on climate, have been a matter of intense debate. Air quality impacts are associated with emissions of nitrogen oxides (NOx = NO + NO2) and volatile organic compounds (VOCs), whose photochemistry leads to production of ozone, a secondary pollutant with negative health effects. Recent observations in oil- and gas-producing basins in the western United States have identified ozone mixing ratios well in excess of present air quality standards, but only during winter. Understanding winter ozone production in these regions is scientifically challenging. It occurs during cold periods of snow cover when meteorological inversions concentrate air pollutants from oil and gas activities, but when solar irradiance and absolute humidity, which are both required to initiate conventional photochemistry essential for ozone production, are at a minimum. Here, using data from a remote location in the oil and gas basin of northeastern Utah and a box model, we provide a quantitative assessment of the photochemistry that leads to these extreme winter ozone pollution events, and identify key factors that control ozone production in this unique environment. We find that ozone production occurs at lower NOx and much larger VOC concentrations than does its summertime urban counterpart, leading to carbonyl (oxygenated VOCs with a C = O moiety) photolysis as a dominant oxidant source. Extreme VOC concentrations optimize the ozone production efficiency of NOx. There is considerable potential for global growth in oil and gas extraction from shale. This analysis could help inform strategies to monitor and mitigate air quality impacts

  5. Short Intramolecular N–H⋯C(carbonyl Interactions in Mixed-Ligand Molybdenum Hexacarbonyl Derivatives

    Directory of Open Access Journals (Sweden)

    Matthew G. Budge

    2011-06-01

    Full Text Available The syntheses and single-crystal structures of Mo(CO3(phen(dipy (1, Mo(CO3(biquin(dipy (2 and Mo(CO3(dpme(dipy (3, (phen = 1,10-phenanthroline, C12H8N2; dipy = 2,2'-dipyridylamine, C10H9N3; biquin = 2,2'-biquinoline, C18H12N2; dpme = 2,2'-dipyridylmethane, C11H10N2 are described. In each case, distorted fac-MoC3N3 octahedral coordination geometries arise for the metal atoms. Short intramolecular N–H…C interactions from the dipy N–H group to a carbonyl carbon atom occur in each structure. Crystal data: 1 (C25H17MoN5O3, Mr = 531.38, monoclinic, P21/n (No. 14, Z = 4, a = 11.0965 (5 Å, b = 13.0586 (6 Å, c = 16.6138 (8 Å, b = 108.324 (1°, V = 2285.31 (18 Å3, R(F = 0.035, wR(F2 = 0.070. 2 (C31H21MoN5O3, Mr = 607.47, monoclinic, P21/n (No. 14, Z = 4, a = 11.4788 (6 Å, b = 19.073 (1 Å, c = 11.9881 (6 Å, b = 95.179 (1°, V = 2613.9 (2 Å3, R(F = 0.030, wR(F2 = 0.076. 3 (C24H19MoN5O3, Mr = 521.38, monoclinic, P21/n (No. 14, Z = 4, a = 8.4222 (3 Å, b = 21.5966 (9 Å, c = 12.5011 (5 Å, b = 94.065 (1°, V = 2268.12 (15 Å3, R(F = 0.025, wR(F2 = 0.065.

  6. Eddy covariance carbonyl sulfide flux measurements with a quantum cascade laser absorption spectrometer

    Science.gov (United States)

    Gerdel, Katharina; Spielmann, Felix M.; Hammerle, Albin; Wohlfahrt, Georg

    2016-04-01

    Carbonyl sulfide (COS) is the most abundant sulfur containing trace gas present in the troposphere at concentrations of around 500 ppt. Recent interest in COS by the ecosystem-physiological community has been sparked by the fact that COS co-diffuses into plant leaves pretty much the same way as carbon dioxide (CO2) does, but in contrast to CO2, COS is not known to be emitted by plants. Thus uptake of COS by vegetation has the potential to be used as a tracer for canopy gross photosynthesis, which cannot be measured directly, however represents a key term in the global carbon cycle. Since a few years, quantum cascade laser absorption spectrometers (QCLAS) are commercially available with the precision, sensitivity and time response suitable for eddy covariance (EC) flux measurements. While there exist a handful of published reports on EC flux measurements in the recent literature, no rigorous investigation of the applicability of QCLAS for EC COS flux measurements has been carried out so far, nor have been EC processing and QA/QC steps developed for carbon dioxide and water vapor flux measurements within FLUXNET been assessed for COS. The aim of this study is to close this knowledge gap, to discuss critical steps in the post-processing chain of COS EC flux measurements and to devise best-practice guidelines for COS EC flux data processing. To this end we collected EC COS (and CO2, H2O and CO) flux measurements above a temperate mountain grassland in Austria over the vegetation period 2015 with a commercially available QCLAS. We discuss various aspects of EC data post-processing, in particular issues with the time-lag estimation between sonic anemometer and QCLAS signals and QCLAS time series detrending, as well as QA/QC, in particular flux detection limits, random flux uncertainty, the interaction of various processing steps with common EC QA/QC filters (e.g. detrending and stationarity tests), u*-filtering, etc.

  7. Canopy uptake dominates nighttime carbonyl sulfide fluxes in a boreal forest

    Science.gov (United States)

    Kooijmans, Linda M. J.; Maseyk, Kadmiel; Seibt, Ulli; Sun, Wu; Vesala, Timo; Mammarella, Ivan; Kolari, Pasi; Aalto, Juho; Franchin, Alessandro; Vecchi, Roberta; Valli, Gianluigi; Chen, Huilin

    2017-09-01

    Nighttime vegetative uptake of carbonyl sulfide (COS) can exist due to the incomplete closure of stomata and the light independence of the enzyme carbonic anhydrase, which complicates the use of COS as a tracer for gross primary productivity (GPP). In this study we derived nighttime COS fluxes in a boreal forest (the SMEAR II station in Hyytiälä, Finland; 61°51' N, 24°17' E; 181 m a.s.l.) from June to November 2015 using two different methods: eddy-covariance (EC) measurements (FCOS-EC) and the radon-tracer method (FCOS-Rn). The total nighttime COS fluxes averaged over the whole measurement period were -6.8 ± 2.2 and -7.9 ± 3.8 pmol m-2 s-1 for FCOS-Rn and FCOS-EC, respectively, which is 33-38 % of the average daytime fluxes and 21 % of the total daily COS uptake. The correlation of 222Rn (of which the source is the soil) with COS (average R2 = 0.58) was lower than with CO2 (0.70), suggesting that the main sink of COS is not located at the ground. These observations are supported by soil chamber measurements that show that soil contributes to only 34-40 % of the total nighttime COS uptake. We found a decrease in COS uptake with decreasing nighttime stomatal conductance and increasing vapor-pressure deficit and air temperature, driven by stomatal closure in response to a warm and dry period in August. We also discuss the effect that canopy layer mixing can have on the radon-tracer method and the sensitivity of (FCOS-EC) to atmospheric turbulence. Our results suggest that the nighttime uptake of COS is mainly driven by the tree foliage and is significant in a boreal forest, such that it needs to be taken into account when using COS as a tracer for GPP.

  8. Eddy covariance carbonyl sulfide flux measurements with a quantum cascade laser absorption spectrometer

    Science.gov (United States)

    Gerdel, Katharina; Spielmann, Felix Maximilian; Hammerle, Albin; Wohlfahrt, Georg

    2017-09-01

    The trace gas carbonyl sulfide (COS) has lately received growing interest from the eddy covariance (EC) community due to its potential to serve as an independent approach for constraining gross primary production and canopy stomatal conductance. Thanks to recent developments of fast-response high-precision trace gas analysers (e.g. quantum cascade laser absorption spectrometers, QCLAS), a handful of EC COS flux measurements have been published since 2013. To date, however, a thorough methodological characterisation of QCLAS with regard to the requirements of the EC technique and the necessary processing steps has not been conducted. The objective of this study is to present a detailed characterisation of the COS measurement with the Aerodyne QCLAS in the context of the EC technique and to recommend best EC processing practices for those measurements. Data were collected from May to October 2015 at a temperate mountain grassland in Tyrol, Austria. Analysis of the Allan variance of high-frequency concentration measurements revealed the occurrence of sensor drift under field conditions after an averaging time of around 50 s. We thus explored the use of two high-pass filtering approaches (linear detrending and recursive filtering) as opposed to block averaging and linear interpolation of regular background measurements for covariance computation. Experimental low-pass filtering correction factors were derived from a detailed cospectral analysis. The CO2 and H2O flux measurements obtained with the QCLAS were compared with those obtained with a closed-path infrared gas analyser. Overall, our results suggest small, but systematic differences between the various high-pass filtering scenarios with regard to the fraction of data retained in the quality control and flux magnitudes. When COS and CO2 fluxes are combined in the ecosystem relative uptake rate, systematic differences between the high-pass filtering scenarios largely cancel out, suggesting that this relative metric

  9. Determination of bond energies by mass spectrometry. Some transition metal carbonyls

    Energy Technology Data Exchange (ETDEWEB)

    Michels, G.D.

    1979-01-01

    Two groups of transition metal carbonyls have been studied, M(CO)/sub 6/ and M(CO)/sub 5/CS complexes of the Group VIB metals and M/sub 2/(CO)/sub 10/ complexes of the Group VIIB metals. Results for the hexacarbonyl complexes indicate that the measured fragmentation energies are in error by 0.25 +- 0.02 eV per CO produced. This is attributed to excitation of CO to the first vibrational state. Least-squares dissociation energies calculated from corrected data for M(CO)/sub 5/CS complexes indicate that the M--CS bond is 3 to 4 times stronger than the M--CO bonds. Substitution of CS for CO in going from M(CO)/sub 6/ to M(CO)/sub 5/CS weakens the remaining M--CO bonds by an average of 0.2 eV. Previously unreported MnTc(CO)/sub 10/ and TcRe(CO)/sub 10/ are prepared by halide substitution of Tc(CO)/sub 5/Br and Re(CO)/sub 5/Br with Mn(CO)/sub 5//sup -/ and Tc(CO)/sub 5//sup -/, respectively. In the positive ion, metal and mixed-metal decacarbonyls are considered as (CO)/sub 5/M/sup +/--M(CO)/sub 5/ complexes possessing five strong and five weak M--CO bonds. For Mn/sub 2/(CO)/sub 10/ and Re/sub 2/(CO)/sub 10/, M/sup +/--M dissociation energies are 3.0 +- 0.1 and 4.0 +- 0.3 eV, respectively. These energies are 2.5 times greater than those reported for homolytic cleavage to M(CO)/sub 5//sup +/ and M(CO)/sub 5/.

  10. Continuous In-situ Measurements of Carbonyl Sulfide to Constrain Ecosystem Carbon and Water Exchange

    Science.gov (United States)

    Rastogi, B.; Kim, Y.; Berkelhammer, M. B.; Noone, D. C.; Lai, C. T.; Hollinger, D. Y.; Bible, K.; Leen, J. B.; Gupta, M.; Still, C. J.

    2014-12-01

    Understanding the processes that control the terrestrial exchange of carbon and water are critical for examining the role of forested ecosystems in changing climates. A small but increasing number of studies have identified Carbonyl Sulfide (OCS) as a potential tracer for photosynthesis. OCS is hydrolyzed by an irreversible reaction in leaf mesophyll cells that is catalyzed by the enzyme, carbonic anhydrase. Leaf-level field and greenhouse studies indicate that OCS uptake is controlled by stomatal activity and that the ratio of OCS and CO2 uptake is reasonably constant. Existing studies on ecosystem OCS exchange have been based on laboratory measurements or short field campaigns and therefore little information on OCS exchange in a natural ecosystem over longer timescales is available. The objective of this study is to further assess the stability of OCS as a tracer for canopy photosynthesis in an active forested ecosystem and also to assess its utility for constraining transpiration, since both fluxes are mediated by canopy stomatal conductance. An off-axis integrated cavity output spectroscopy analyzer (Los Gatos Research Inc.) was deployed at the Wind River Experimental Forest in Washington (45.8205°N, 121.9519°W). Canopy air was sampled from three heights to measure vertical gradients of OCS within the canopy, and OCS exchange between the forest and the atmosphere. Here we take advantage of simultaneous measurements of the stable isotopologues of H2O and CO2 at corresponding heights as well as NEE (Net Ecosystem Exchange) from eddy covariance measurements to compare GPP (Gross Primary Production) and transpiration estimates from a variety of independent techniques. Our findings seek to allow assessment of the environmental and ecophysicological controls on evapotranspiration rates, which are projected to change in coming decades, and are otherwise poorly constrained.

  11. High winter ozone pollution from carbonyl photolysis in an oil and gas basin.

    Science.gov (United States)

    Edwards, Peter M; Brown, Steven S; Roberts, James M; Ahmadov, Ravan; Banta, Robert M; deGouw, Joost A; Dubé, William P; Field, Robert A; Flynn, James H; Gilman, Jessica B; Graus, Martin; Helmig, Detlev; Koss, Abigail; Langford, Andrew O; Lefer, Barry L; Lerner, Brian M; Li, Rui; Li, Shao-Meng; McKeen, Stuart A; Murphy, Shane M; Parrish, David D; Senff, Christoph J; Soltis, Jeffrey; Stutz, Jochen; Sweeney, Colm; Thompson, Chelsea R; Trainer, Michael K; Tsai, Catalina; Veres, Patrick R; Washenfelder, Rebecca A; Warneke, Carsten; Wild, Robert J; Young, Cora J; Yuan, Bin; Zamora, Robert

    2014-10-16

    The United States is now experiencing the most rapid expansion in oil and gas production in four decades, owing in large part to implementation of new extraction technologies such as horizontal drilling combined with hydraulic fracturing. The environmental impacts of this development, from its effect on water quality to the influence of increased methane leakage on climate, have been a matter of intense debate. Air quality impacts are associated with emissions of nitrogen oxides (NOx = NO + NO2) and volatile organic compounds (VOCs), whose photochemistry leads to production of ozone, a secondary pollutant with negative health effects. Recent observations in oil- and gas-producing basins in the western United States have identified ozone mixing ratios well in excess of present air quality standards, but only during winter. Understanding winter ozone production in these regions is scientifically challenging. It occurs during cold periods of snow cover when meteorological inversions concentrate air pollutants from oil and gas activities, but when solar irradiance and absolute humidity, which are both required to initiate conventional photochemistry essential for ozone production, are at a minimum. Here, using data from a remote location in the oil and gas basin of northeastern Utah and a box model, we provide a quantitative assessment of the photochemistry that leads to these extreme winter ozone pollution events, and identify key factors that control ozone production in this unique environment. We find that ozone production occurs at lower NOx and much larger VOC concentrations than does its summertime urban counterpart, leading to carbonyl (oxygenated VOCs with a C = O moiety) photolysis as a dominant oxidant source. Extreme VOC concentrations optimize the ozone production efficiency of NOx. There is considerable potential for global growth in oil and gas extraction from shale. This analysis could help inform strategies to monitor and mitigate air quality impacts

  12. Measurements of C{sub 1}-C{sub 4} carbonyls at forested regions in Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Ceron Breton, J.B.; Padilla, H.; Belmont, R.; Torres, M.C.; Moya, M.; Baez, A.P. [Centro de Ciencias de la Atmosfera, Universidad Nacional Autonoma de Mexico, UNAM, Mexico, D.F. (Mexico)

    2005-04-01

    Measurements of formaldehyde, acetaldehyde, acetone, propionaldehyde and butyraldehyde concentrations were made at five different forested regions in Mexico. One set of two simultaneous samplings was performed at two sites located in the Mexico State, one semi rural area (Temascaltepec), and the other, a forested area (Rancho Viejo). A second set of two simultaneous samplings were made in southern Veracruz State, in one rural area (Monte Pio) and inside a tropical rainforest (at the Biology Station of the University of Mexico). Finally, one sampling was performed in the Sierra of Puebla State (Cuetzalan). Propionaldehyde and butyraldehyde were nor reported because their concentrations were always below or near the detection limit of the technique. The highest concentrations were found from 7:00 to 11:00 and from 11:00 to 19:00 h in all the sampling sites. Arithmetic mean concentrations of acetone were the highest observed among the detected carbonyl compounds in almost all sites, ranging from 0.5 to 8.4 {mu}g m{sup -}3. Arithmetic mean concentrations of formaldehyde and acetaldehyde ranged from 0.83 to 6 {mu}g m{sup -}3 and 0.53 to 4.7 {mu}g m{sup -}3, respectively. The Spearman's correlations between formaldehyde and acetone, and between acetaldehyde and acetone were statistically significant at p<0.05 in almost all sites. A significant correlation (p<0.05) between formaldehyde and acetaldehyde was observed in Mexico State at Rancho Viejo and Temascaltepec. The mean ratio HCHO/CH{sub 3}CHO of concentrations was 1.83 and 1.31 in the forested area of Rancho Viejo, first and second sampling periods, respectively; 1.71 and 1.62 in the semi rural area of Temascaltepec, first and second sampling periods respectively; 1.70 in Cuetzalan; 2.90 in the rural area of Monte Pio; and 1.61 in the Biology Station tropical rainforest. These values show a greater influence of atmospheric pollutants transported from sites with anthropogenic activities, because HCHO/CH{sub 3}CHO

  13. ANAEROBIC VS. AEROBIC PATHWAYS OF CARBONYL AND OXIDANT STRESS IN HUMAN LENS AND SKIN DURING AGING AND IN DIABETES: A COMPARATIVE ANALYSIS

    Science.gov (United States)

    Fan, Xingjun; Sell, David R; Zhang, Jianye; Nemet, Ina; Theves, Mathilde; Lu, Jie; Strauch, Christopher; Halushka, Marc K.; Monnier, Vincent M.

    2010-01-01

    The effects of anaerobic (lens) vs aerobic (skin) environment on carbonyl and oxidant stress are compared using de novo and existing data on advanced glycation and oxidation products in human crystallins and collagen. Almost all modifications increase with age. Methylglyoxal hydroimidazolones (MG-H1), carboxymethyl-lysine (CML), and carboxyethyl-lysine (CEL) are several folds higher in lens than skin, and markedly increase upon incubation of lens crystallins with 5 mM ascorbic acid. Vice-versa, fructose-lysine, glucosepane crosslinks, glyoxal hydroimidazolones (G-H1), metal catalyzed oxidation (allysine) and H2O2 dependent modifications (2-aminoapidic acid and methionine sulfoxide) are markedly elevated in skin, but relatively suppressed in the aging lens. In both tissues ornithine is the dominant modification, implicating arginine residues as the principal target of the Maillard reaction in vivo. Diabetes (here mostly type 2 studied) increases significantly fructose-lysine and glucosepane in both tissues (Pascorbate is predominant in the aging non-cataractous lens, while aging skin collagen undergoes combined attack by non-oxidative glucose mediated modifications, as well as those from metal catalyzed oxidation and H2O2. PMID:20541005

  14. Anaerobic vs aerobic pathways of carbonyl and oxidant stress in human lens and skin during aging and in diabetes: A comparative analysis.

    Science.gov (United States)

    Fan, Xingjun; Sell, David R; Zhang, Jianye; Nemet, Ina; Theves, Mathilde; Lu, Jie; Strauch, Christopher; Halushka, Marc K; Monnier, Vincent M

    2010-09-01

    The effects of anaerobic (lens) vs aerobic (skin) environment on carbonyl and oxidant stress are compared using de novo and existing data on advanced glycation and oxidation products in human crystallins and collagen. Almost all modifications increase with age. Methylglyoxal hydroimidazolones, carboxymethyllysine, and carboxyethyllysine are severalfold higher in lens than in skin and markedly increase upon incubation of lens crystallins with 5mM ascorbic acid. In contrast, fructose-lysine, glucosepane crosslinks, glyoxal hydroimidazolones, metal-catalyzed oxidation (allysine), and H(2)O(2)-dependent modifications (2-aminoapidic acid and methionine sulfoxide) are markedly elevated in skin, but relatively suppressed in the aging lens. In both tissues ornithine is the dominant modification, implicating arginine residues as the principal target of the Maillard reaction in vivo. Diabetes (here mostly type 2 studied) increases significantly fructose-lysine and glucosepane in both tissues (Pdiabetes strengthens the Spearman correlation coefficients for age-related accumulation of hydrogen peroxide-mediated modifications in the lens. Overall, the data suggest that oxoaldehyde stress involving methylglyoxal from either glucose or ascorbate is predominant in the aging noncataractous lens, whereas aging skin collagen undergoes combined attack by nonoxidative glucose-mediated modifications, as well as those from metal-catalyzed oxidation and H(2)O(2). Copyright 2010 Elsevier Inc. All rights reserved.

  15. Biosynthesis of tert-butyl (3R,5S)-6-chloro-3,5-dihydroxyhexanoate by carbonyl reductase from Rhodosporidium toruloides in mono and biphasic media.

    Science.gov (United States)

    Liu, Zhi-Qiang; Wu, Lin; Zheng, Ling; Wang, Wen-Zhong; Zhang, Xiao-Jian; Jin, Li-Qun; Zheng, Yu-Guo

    2017-10-05

    tert-Butyl (3R,5S)-6-chloro-3,5-dihydroxyhexanoate ((3R,5S)-CDHH) is the key intermediate for synthesis of atorvastatin and rosuvastatin. Carbonyl reductase exhibits excellent activity toward tert-butyl (S)-6-chloro-5-hydroxy-3-oxohexanoate ((S)-CHOH) to synthesize (3R,5S)-CDHH. In this study, a whole cell biosynthesis reaction system to produce (3R,5S)-CDHH was constructed in organic solvents. A solution of 10% (v/v) Tween-80 was introduced to the reaction system as a co-solvent, which greatly enhanced biotransformation process, giving 98.9% yield, >99% ee and 1.8-fold higher space time yield in 5 h bioconversion of 1 M (S)-CHOH, compared with 98.7% yield and >99% ee in 9 h bioconversion of a purely aqueous reaction system. Moreover, a water-octanol biphasic reaction system was built and 20% of octanol was added as reservoir of substrate resulting in 98% yield, >99% ee and 4.08 mmol L-1 h-1 g-1 (wet cell weight) space time yield. This study paved a way for the whole cell biosynthesis of (3R,5S)-CDHH in mono and biphasic media. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Improved rheological properties of dimorphic magnetorheological gels based on flower-like carbonyl iron particles

    Science.gov (United States)

    Yang, Pingan; Yu, Miao; Luo, Hongping; Fu, Jie; Qu, Hang; Xie, Yuanpeng

    2017-09-01

    In this study, a new kind of dimorphic magnetorheological gels (MRGs) based on the conventional carbonyl iron particles (CIPs) and flower-like CIPs have been prepared for improving the yield stress and dynamic mechanical properties. The flower-like CIPs are synthesized by a simple and facile in situ reduction method. Characterization results indicate that the flower-like CIPs are synthesized successfully and a layer of uniform and continuous Fe nanosheets are grown on the surface of the raw microsphere CIPs. In addition, the flower-like CIPs exhibit excellent magnetic properties, which the saturated mass magnetization (Ms) can achieve 168.76 emu/g. In order to study the influence of mass fraction of flower-like CIPs on the rheological properties of this dimorphic MRGs, a series of polyurethane-based dimorphic MRGs are prepared by partial substitution of the CIPs with as-synthesized flower-like CIPs, and the MR properties of them are systematically investigated under both oscillatory and rotational shear modes. The experimental results indicate that, with 8 wt% flower-like CIPs, the maximum dynamic yield stresses and magneto-induced shear yield stress of dimorphic MRGs are 58.11 kPa and 54.53 kPa, ∼1.39 and ∼1.37 times of the MRG without flower-like CIPs at the same magnetic particle content. Moreover, the average loss factor and the loss factor under 1 T of the sample (flower-like CIPs weight content 8 wt%) are 0.36 and 0.07, which are approximately 1.71 and 2.71 times than that in the non-substitution sample. The increased loss factor is beneficial to improving the vibration reduction effect of MRGs of damping devices in the whole magnetic field region. Furthermore, the possible mechanism for the enhanced MR properties in dimorphic MRGs is proposed. In summary, this work is expected to promote the design and application of MRG devices.

  17. Two-step milling on the carbonyl iron particles and optimizing on the composite absorption

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Yonggang, E-mail: xuyonggang221@163.com [Science and Technology on Electromagnetic Scattering Laboratory, Shanghai 200438 (China); Yuan, Liming; Wang, Xiaobing [Science and Technology on Electromagnetic Scattering Laboratory, Shanghai 200438 (China); Zhang, Deyuan [Bionic and Micro/Nano/Bio Manufacturing Technology Research Center, School of Mechanical Engineering and Automation, Beihang University, Beijing 100191 (China)

    2016-08-15

    The flaky carbonyl iron particles (CIPs) were prepared using a two-step milling process. The surface morphology was characterized by the scanning electron microscopy, the static magnetic property was evaluated on a vibrating sample magnetometer and X-ray diffraction (XRD) patterns were done to analyze the particle crystal grain structure. The complex permittivity and permeability were measured using a vector network analyzer in the frequency range of 2–18 GHz. Then Hermite interpolation based on the calculated scattering parameters of the tested composite was used to derive the permittivity and permeability of the composite with random volume content. The results showed that the saturation magnetization value of the flaky CIPs decreased as the CIPs was changed to the flakes by high and low speeding milling. The diffraction peaks of the single α-Fe existed in the XRD pattern of CIPs, and the characteristic peaks was broad and the intensity of the diffraction pattern was lower as the high-speeding milling time increased. The sample H2L20 had the largest particle size, the average diameter was 8.64 μm, the thickness was 0.59 μm according to the fitted aspect ratio 14.65. The derived permittivity and permeability using the Hermite interpolation was accurate compared with the tested result, the deviation was about 0.39 + j0.45 and 2.5 + j0.51. Finally, the genetic algorithm was used to optimize the thickness of the CIPs composite of a wide absorbing band of 8–18 GHz. The optimized reflection loss (RL) result showed that the absorbing composites with thickness 1.47 mm had an excellent absorbing property (RL < −10 dB) in 8–18 GHz. - Graphical abstract: The property of absorber added two speeding milling CIPs could be enhanced using the genetic algorithm. - Highlights: • Flaky CIPs were prepared using a two-step milling process. • The permeability increased during the low speeding milling. • The aspect ratio of flaky CIPs increased in the optimized process

  18. Kinetics of reversible reductive carbonylation of heme in human cystathionine β-synthase.

    Science.gov (United States)

    Carballal, Sebastián; Cuevasanta, Ernesto; Marmisolle, Inés; Kabil, Omer; Gherasim, Carmen; Ballou, David P; Banerjee, Ruma; Alvarez, Beatriz

    2013-07-02

    Cystathionine β-synthase (CBS) catalyzes the condensation of homocysteine with serine or cysteine to form cystathionine and water or hydrogen sulfide (H2S), respectively. In addition to pyridoxal phosphate, human CBS has a heme cofactor with cysteine and histidine as ligands. While Fe(III)-CBS is inert to exogenous ligands, Fe(II)-CBS can be reversibly inhibited by carbon monoxide (CO) and reoxidized by O2 to yield superoxide radical. In this study, we have examined the kinetics of Fe(II)CO-CBS formation and reoxidation. Reduction of Fe(III)-CBS by dithionite showed a square root dependence on concentration, indicating that the reductant species was the sulfur dioxide radical anion (SO2(•-)) that exists in rapid equilibrium with S2O4(2-). Formation of Fe(II)CO-CBS from Fe(II)-CBS and 1 mM CO occurred with a rate constant of (3.1 ± 0.4) × 10(-3) s(-1) (pH 7.4, 25 °C). The reaction of Fe(III)-CBS with the reduced form of the flavoprotein methionine synthase reductase in the presence of CO and NADPH resulted in its reduction and carbonylation to form Fe(II)CO-CBS. Fe(II)-CBS was formed as an intermediate with a rate constant of (9.3 ± 2.5) × 10(2) M(-1) s(-1). Reoxidation of Fe(II)CO-CBS by O2 was multiphasic. The major phase showed a hyperbolic dependence on O2 concentration. Although H2S is a product of the CBS reaction and a potential heme ligand, we did not find evidence of an effect of exogenous H2S on activity or heme binding. Reversible reduction of CBS by a physiologically relevant oxidoreductase is consistent with a regulatory role for the heme and could constitute a mechanism for cross talk among the CO, H2S, and superoxide signaling pathways.

  19. Soil water content plays an important role in soil-atmosphere exchange of carbonyl sulfide (OCS)

    Science.gov (United States)

    Yi, Zhigang; Behrendt, Thomas; Bunk, Rüdiger; Wu, Dianming; Kesselmeier, Jürgen

    2016-04-01

    Carbonyl sulfide (OCS) is a quite stable gas in the troposphere and is transported up to the stratosphere, where it contributes to the sulfate aerosol layer (Crutzen 1976). The tropospheric concentration seems to be quite constant, indicating a balance between sinks and sources. Recent work by Sandoval-Soto et al. (2005) demonstrated the enormous strength of the vegetation sink and the urgent needs to understand the sinks and sources. The role of soils is a matter of discussion (Kesselmeier et al., 1999; Van Diest and Kesselmeier, 2008; Maseyk et al., 2014; Whelan et al., 2015). To better understand the influence of soil water content and OCS mixing ratio on OCS fluxes, we used an OCS analyzer (LGR COS/CO Analyzer 907-0028, Los Gatos, CA, USA) coupled with automated soil chamber system (Behrendt et al., 2014) to measure the OCS fluxes with a slow drying of four different types of soil (arable wheat soil in Mainz, blueberry soil in Waldstein, spruce soil in Waldstein and needle forest soil in Finland). Results showed that OCS fluxes as well as the optimum soil water content for OCS uptake varied significantly for different soils. The net production rates changed significantly with the soil drying out from 100% to about 5% water holding capacity (WHC), implying that soil water content play an important role in the uptake processes. The production and uptake processes were distinguished by the regression of OCS fluxes under different OCS mixing ratios. OCS compensation points (CP) were found to differ significantly for different soil types and water content, with the lowest CP at about 20% WHC, implying that when estimating the global budgets of OCS, especially for soils fluxes, soil water content should be taken into serious consideration. References Crutzen, P. J. 1976, Geophys. Res. Lett., 3, 73-76. Sandoval-Soto, L. et al., 2005, Biogeosciences, 2, 125-132. Kesselmeier, J. et al., 1999, J. Geophys. Res., 104, 11577-11584. Van Diest, H. and Kesselmeier, J. 2008

  20. EVA reactive blending with Si-H terminated polysiloxane by carbonyl hydrosilylation reaction: From compatibilised blends to crosslinking networks

    Energy Technology Data Exchange (ETDEWEB)

    Bonnet, J.; Bounor-Legare, V.; Alcouffe, P. [Universite de Lyon, 69003 Lyon (France); Universite de Lyon 1, CNRS UMR5223, Ingenierie des Materiaux Polymeres, 15 Boulevard Latarjet, F-69622 Villeurbanne (France); Cassagnau, P., E-mail: philippe.cassagnau@univ-lyon1.fr [Universite de Lyon, 69003 Lyon (France); Universite de Lyon 1, CNRS UMR5223, Ingenierie des Materiaux Polymeres, 15 Boulevard Latarjet, F-69622 Villeurbanne (France)

    2012-10-15

    A new and original method based on carbonyl hydrosilylation was developed to prepare ethylene-vinyl acetate (EVA)/polysiloxane polymer blends. This focused on the addition of hydrogenosilane groups (SiH) from polysiloxane to the carbonyl groups of EVA. The influence of the nature of the polysiloxane on blend properties was investigated by rheology and scanning electron microscopy. Mixing of a low viscosity polysiloxane with a high viscosity EVA matrix produced a two-phase morphology. The occurrence of the hydrosilylation reaction at the EVA/polysiloxane interface promoted a homogenisation of the blend depending on the molar ratio SiH/vinyl acetate groups, [SiH]/[VA], and the viscosity ratio of the blend. Two distinct behaviours were observed. The formation of a crosslinked network under shear was obtained for a low viscosity ratio between polysiloxane and EVA ({lambda}{sub polysiloxane/EVA} = 4.0 Multiplication-Sign 10{sup -6}) with a high concentration of SiH groups ([SiH]/[VA] = 0.5), while the formation of a compatibilised blend was observed for high molar mass polysiloxanes (Mn > 15,000 g mol{sup -1}) with a low concentration of SiH ([SiH]/[VA] < 4.0 Multiplication-Sign 10{sup -3}). -- Highlights: Black-Right-Pointing-Pointer Carbonyl hydrosilylation reaction was found to enhance EVA/polysiloxane immiscible blends. Black-Right-Pointing-Pointer EVA crosslinking was obtained with a low molar mass polysiloxane. Black-Right-Pointing-Pointer EVA compatibilisation was obtained with a high molar mass polysiloxane. Black-Right-Pointing-Pointer Shear rate was found to improve the hydrosilylation reaction at the interface. Black-Right-Pointing-Pointer A two-phase morphology of the blends was observed after reaction with fine polysiloxane nodules.

  1. Redox Proteomic Profiling of Specifically Carbonylated Proteins in the Serum of Triple Transgenic Alzheimer’s Disease Mice

    Directory of Open Access Journals (Sweden)

    Liming Shen

    2016-04-01

    Full Text Available Oxidative stress is a key event in the onset and progression of neurodegenerative diseases, including Alzheimer’s disease (AD. To investigate the role of oxidative stress in AD and to search for potential biomarkers in peripheral blood, serums were collected in this study from the 3-, 6-, and 12-month-old triple transgenic AD mice (3×Tg-AD mice and the age- and sex-matched non-transgenic (non-Tg littermates. The serum oxidized proteins were quantified by slot-blot analysis and enzyme-linked immunosorbent assay (ELISA to investigate the total levels of serum protein carbonyl groups. Western blotting, in conjunction with two-dimensional gel electrophoresis (2D-Oxyblot, was employed to identify and quantify the specifically-carbonylated proteins in the serum of 3×Tg-AD mice. The results showed that the levels of serum protein carbonyls were increased in the three month old 3×Tg-AD mice compared with the non-Tg control mice, whereas no significant differences were observed in the six and 12 months old AD mice, suggesting that oxidative stress is an early event in AD progression. With the application of 2D-Oxyblot analysis, (immunoglobin Ig gamma-2B chain C region (IGH-3, Ig lambda-2 chain C region (IGLC2, Ig kappa chain C region (IGKC, and Ig kappa chain V-V region HP R16.7 were identified as significantly oxidized proteins compared with the control. Among them IGH-3 and IGKC were validated via immunoprecipitation and Western blot analysis. Identification of oxidized proteins in the serums of 3×Tg-AD mice can not only reveal potential roles of those proteins in the pathogenesis of AD but also provide potential biomarkers of AD at the early stage.

  2. Cell signaling promoting protein carbonylation does not cause sulfhydryl oxidation: Implications to the mechanism of redox signaling.

    Science.gov (United States)

    Suzuki, Yuichiro J; Almansour, Faisal; Cucinotta, Camilla; Rybka, Vladyslava; Marcocci, Lucia

    2017-01-01

    Reactive oxygen species (ROS) have been recognized as second messengers, however, targeting mechanisms for ROS in cell signaling have not been defined. While ROS oxidizing protein cysteine thiols has been the most popular proposed mechanism, our laboratory proposed that ligand/receptor-mediated cell signaling involves protein carbonylation. Peroxiredoxin-6 (Prx6) is one protein that is carbonylated at 10 min after the platelet-derived growth factor (PDGF) stimulation of human pulmonary artery smooth muscle cells. In the present study, the SulfoBiotics Protein Redox State Monitoring Kit Plus (Dojindo Molecular Technologies) was used to test if cysteine residues of Prx6 are oxidized in response to the PDGF stimulation. Human Prx6 has a molecular weight of 25 kDa and contains two cysteine residues. The Dojindo system adds the 15 kDa Protein-SHifter if these cysteine residues are reduced in the cells. Results showed that, in untreated cells, the Prx6 molecule predominantly exhibited the 55 kDa band, indicating that both cysteine residues are reduced in the cells. Treatment of cells with 1 mM H 2O 2 caused the disappearance of the 55 kDa band and the appearance of a 40 kDa band, suggesting that the high concentration of H 2O 2 oxidized one of the two cysteine residues in the Prx6 molecule. By contrast, PDGF stimulation had no effects on the thiol status of the Prx6 molecule. We concluded that protein carbonylation is a more sensitive target of ROS during ligand/receptor-mediated cell signaling than sulfhydryl oxidation.

  3. Synthesis and Characterization of Tc(I) Carbonyl Nitrosyl Species Relevant to the Hanford Tank Waste: FY 2016 Status Report

    Energy Technology Data Exchange (ETDEWEB)

    Hall, Gabriel B. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Chatterjee, Sayandev [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Levitskaia, Tatiana G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Martin, Thibaut J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Wall, Nathalie [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Walter, Eric D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-11-24

    Among long-lived radioactive constituents in the Hanford tank waste, Tc presents a unique challenge in that it exists predominantly in the liquid phase, generally in the anionic form of pertechnetate, TcO4-, which is highly volatile at low-activity waste (LAW) vitrification melter temperatures and mobile in the Hanford site’s subsurface environment. The complex behavior of Tc under storage, treatment, and immobilization conditions significantly affects its management options, which to-date remain uncertain. In strongly alkaline environments, Tc exists as pertechnetate, TcO4- (oxidation state +7), and in the reduced forms (oxidation state < +7) collectively known as non-pertechnetate species. Pertechnetate is a well-characterized, anionic Tc species that can be removed from LAW by anion exchange or solvent extraction methods. There is no definitive information on the origin of the non-pertechnetate Tc species, nor is there a comprehensive description of their composition and behavior. It has been recently proposed that the non-pertechnetate species can comprise Tc(I) metal center and carbonyl or mixed carbonyl nitrosyl ligands stabilizing low-valent Tc. Recent work by our group has significantly expanded this previous work, generating a series of Tc(I) carbonyl compounds and demonstrating that they can be generated from reduction of TcO4- in the simulated Hanford tank waste in presence of CO at elevated temperature (Levitskaia et al. 2014). These results are consistent with the previous proposal that [Tc(CO)3]+ species can be present in the Hanford tank waste and suggest that the low Tc(I) oxidation state is stabilized by the π-accepting ability of the CO ligands. The continuation work has been initiated to develop model Tc carbonyl nitrosyl compounds and investigate their potential presence in the Hanford tank wastes. This report summarizes our to-date results.

  4. The Development and Application of Two-Chamber Reactors and Carbon Monoxide Precursors for Safe Carbonylation Reactions.

    Science.gov (United States)

    Friis, Stig D; Lindhardt, Anders T; Skrydstrup, Troels

    2016-04-19

    Low molecular weight gases (e.g., carbon monoxide, hydrogen, and ethylene) represent vital building blocks for the construction of a wide array of organic molecules. Whereas experimental organic chemists routinely handle solid and liquid reagents, the same is not the case for gaseous reagents. Synthetic transformations employing such reagents are commonly conducted under pressure in autoclaves or under atmospheric pressure with a balloon setup, which necessitates either specialized equipment or potentially hazardous and nonrecommended installations. Other safety concerns associated with gaseous reagents may include their toxicity and flammability and, with certain gases, their inability to be detected by human senses. Despite these significant drawbacks, industrial processes apply gaseous building blocks regularly due to their low cost and ready availability but nevertheless under a strictly controlled manner. Carbon monoxide (CO) fits with all the parameters for being a gas of immense industrial importance but with severe handling restrictions due to its inherent toxicity and flammability. In academia, as well as research and development laboratories, CO is often avoided because of these safety issues, which is a limitation for the development of new carbonylation reactions. With our desire to address the handling of CO in a laboratory setting, we designed and developed a two-chamber reactor (COware) for the controlled delivery and utilization of stoichiometric amounts of CO for Pd-catalyzed carbonylation reactions. In addition to COware, two stable and solid CO-releasing molecules (COgen and SilaCOgen) were developed, both of which release CO upon activation by either Pd catalysis or fluoride addition, respectively. The unique combination of COware with either COgen or SilaCOgen provides a simple reactor setup enabling synthetic chemists to easily perform safe carbonylation chemistry without the need for directly handling the gaseous reagent. With this technology

  5. Alkyloxy carbonyl modified hexapeptides as a high affinity compounds for Wnt5A protein in the treatment of psoriasis

    OpenAIRE

    Kelotra, Ankit; Gokhale, Sadashiv M; Kelotra, Seema; Mukadam, Vaidehi; Nagwanshi, Komal; Bandaru, Srinivas; Nayarisseri, Anuraj; Bidwai, Anil

    2014-01-01

    Psoriasis is one of the most prevalent chronic inflammatory diseases of the skin. The Wnt pathways have been documented to play essential role in stem cell self-renewal and keratinocyte differentiation in the skin. Antagonizing the Wnt5a protein would emerge as a novel therapeutics in psoriasis treatment. In this view, we have developed and characterized series of compounds by attaching varied tertiary alkyloxy carbonyl groups at the N-terminal end of the hexapeptide (Met-Asp-Gly-Cys-Glu-Leu)...

  6. Microwave absorbing paints and sheets based on carbonyl iron and polyaniline: measurement and simulation of their properties

    Directory of Open Access Journals (Sweden)

    Luiza de C. Folgueras

    2010-04-01

    Full Text Available This paper presents the processing and characterization of electromagnetic radiation absorbing paints and sheets based on magnetic and dielectric materials dispersed in polymeric matrices. Two different paint formulations containing carbonyl iron and/or polyaniline, using polyurethane as matrix, were prepared. Silicone sheets were also produced with polyaniline conducting polymer as filler. Measurements of the electric permittivity and magnetic permeability of the materials were also carried out. Simulations for the silicone sheets were performed in order to correlate the electromagnetic parameters with the material thickness. The paints absorbed 60 to 80% of the incident electromagnetic radiation and the silicone sheets absorbed 90%, indicating the material’s radar absorbing potential.

  7. Three-dimensional imaging of carbonyl sulfide and ethyl iodide photodissociation using the pixel imaging mass spectrometry camera.

    Science.gov (United States)

    Amini, K; Blake, S; Brouard, M; Burt, M B; Halford, E; Lauer, A; Slater, C S; Lee, J W L; Vallance, C

    2015-10-01

    The Pixel Imaging Mass Spectrometry (PImMS) camera is used in proof-of-principle three-dimensional imaging experiments on the photodissociation of carbonyl sulfide and ethyl iodide at wavelengths around 230 nm and 245 nm, respectively. Coupling the PImMS camera with DC-sliced velocity-map imaging allows the complete three-dimensional Newton sphere of photofragment ions to be recorded on each laser pump-probe cycle with a timing precision of 12.5 ns, yielding velocity resolutions along the time-of-flight axis of around 6%-9% in the applications presented.

  8. Compostos carbonílicos atmosféricos: fontes, reatividade, níveis de concentração e efeitos toxicológicos Atmospheric carbonyl compounds: sources, reactivity, concentration levels and toxicologic effects

    Directory of Open Access Journals (Sweden)

    Marta Valéria Almeida Santana de Andrade

    2002-12-01

    Full Text Available In the last three decades carbonyl compounds, aldehydes and ketones, have received a great deal of attention due to their strong influence on photochemical smog formation and their recognized adverse human health effects. Carbonyl compounds are directly emitted into the atmosphere by combustion sources and also produced from photochemical oxidation of hydrocarbons and other organic compounds. In this paper it is presented a general overview about the carbonyl compounds sources, reactivity, concentration levels and toxicological effects.

  9. The use of biodiesel blends on a non-road generator and its impacts on ozone formation potentials based on carbonyl emissions.

    Science.gov (United States)

    Chai, Ming; Lu, Mingming; Liang, Fuyan; Tzillah, Aisha; Dendramis, Nancy; Watson, Libya

    2013-07-01

    In this study, emissions of carbonyl compounds from the use B50 and B100 were measured with a non-road diesel generator. A total of 25 carbonyl compounds were identified in the exhaust, including 10 with laboratory-synthesized standards. Formaldehyde, acetaldehyde, and acrolein were found as the most abundant carbonyl compounds emitted for both diesel and biodiesel. The sulphur content of diesel fuels and the source of biodiesel fuels were not found to have a significant impact on the emission of carbonyl compounds. The overall maximum incremental reactivity (MIR) was the highest at 0 kW and slightly increased from 25 to 75 kW. The MIR of B100 was the highest, followed by diesel and B50, which is consistent with the emission rates of total carbonyl compounds. This suggests that the use of biodiesel blends may be more beneficial to the environment than using pure biodiesel. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. The serotonin-1A receptor distribution in healthy men and women measured by PET and [carbonyl-{sup 11}C]WAY-100635

    Energy Technology Data Exchange (ETDEWEB)

    Stein, Patrycja; Savli, Markus; Fink, Martin; Spindelegger, Christoph; Moser, Ulrike; Kasper, Siegfried; Lanzenberger, Rupert [Medical University of Vienna, Department of Psychiatry and Psychotherapy, Vienna (Austria); Wadsak, Wolfgang; Dudczak, Robert; Kletter, Kurt [Medical University of Vienna, Department of Nuclear Medicine, Vienna (Austria); Mitterhauser, Markus; Mien, Leonhard-Key [Medical University of Vienna, Department of Nuclear Medicine, Vienna (Austria); University of Vienna, Department of Pharmaceutical Technology, Vienna (Austria)

    2008-12-15

    The higher prevalence rates of depression and anxiety disorders in women compared to men have been associated with sexual dimorphisms in the serotonergic system. The present positron emission tomography (PET) study investigated the influence of sex on the major inhibitory serotonergic receptor subtype, the serotonin-1A (5-HT{sub 1A}) receptor. Sixteen healthy women and 16 healthy men were measured using PET and the highly specific radioligand [carbonyl-{sup 11}C]WAY-100635. Effects of age or gonadal hormones were excluded by restricting the inclusion criteria to young adults and by controlling for menstrual cycle phase. The 5-HT{sub 1A} receptor BP{sub ND} was quantified using (1) the 'gold standard' manual delineation approach with ten regions of interest (ROIs) and (2) a newly developed delineation method using a PET template normalized to the Montreal Neurologic Institute space with 45 ROIs based on automated anatomical labeling. The 5-HT{sub 1A} receptor BP{sub ND} was found equally distributed in men and women applying both the manual delineation method and the automated delineation approach. Women had lower mean BP{sub ND} values in every region investigated, with a borderline significant sex difference in the hypothalamus (p=0.012, uncorrected). There was a high intersubject variability of the 5-HT{sub 1A} receptor BP{sub ND} within both sexes compared to the small mean differences between men and women. To conclude, when measured in the follicular phase, women do not differ from men in the 5-HT{sub 1A} receptor binding. To explain the higher prevalence of affective disorders in women, further studies are needed to evaluate the relationship between hormonal status and the 5-HT{sub 1A} receptor expression. (orig.)

  11. Aluminium, carbonyls and cytokines in human nipple aspirate fluids: Possible relationship between inflammation, oxidative stress and breast cancer microenvironment.

    Science.gov (United States)

    Mannello, F; Ligi, D; Canale, M

    2013-11-01

    The human breast is likely exposed to Al (aluminium) from many sources including diet and personal care products. Underarm applications of aluminium salt-based antiperspirant provide a possible long-term source of exposure, especially after underarm applications to shaved and abraded skin. Al research in breast fluids likely reflects the intraductal microenvironment. We found increased levels of aluminium in noninvasively collected nipple aspirate fluids (NAF) from 19 breast cancer patients compared with 16 healthy control subjects (268 vs 131 μg/l, respectively; p Aluminium content and carbonyl levels showed a significant positive linear correlation (r(2) 0.6628, p aluminium salts) we also found a significantly increased levels of pro-inflammatory cytokines (IL-1β, IL-6, IL-12 p70, and TNF-α) and chemoattractant CC and CXC chemokines (IL-8, MIP-1α and MCP-1). In 12 invasive cancer NAF samples we found a significant positive linear correlation among aluminium, carbonyls and pro-inflammatory IL-6 cytokine (Y = 64.79x-39.63, r(2) 0.8192, p aluminium ions in oxidative and inflammatory status perturbations of breast cancer microenvironment, suggesting aluminium accumulation in breast microenvironment as a possible risk factor for oxidative/inflammatory phenotype of breast cells. © 2013.

  12. Analysis of 31 Hydrazones of Carbonyl Compounds by RRLC-UV and RRLC-MS(/MS: A Comparison of Methods

    Directory of Open Access Journals (Sweden)

    Soraya de M. Ochs

    2015-01-01

    Full Text Available Aldehydes and ketones are volatile organic compounds (VOC emitted into the atmosphere by a large number of natural and anthropogenic sources. Carbonyl compounds (CC are atmospheric pollutants with known damaging effects for the human’s health. In this work, the separation of 31 carbonyl compounds (CC in their 2,4-dinitrophenylhydrazones form was optimized by rapid resolution liquid chromatography in 9 minutes and simultaneously detected by ultraviolet and mass spectrometry with an APCI(− as ionization source. The mass spectra of hydrazones presented the [M-H]− ions as base peak, but the MS/MS spectra showed fragments related to different structural classes of aldehydes and ketones, representing an important tool to assist structure elucidation of unknown CC in real samples. Multiple reactions monitoring (MRM improved the sensitivity and selectivity for the quantitation method. Analytical parameters using both UV and MS (linearity, determination coefficients, detection limits, and sensitivity were compared. The detection methods are complementary and a powerful analytical tool for the detection and quantitation of CC in complex environmental samples.

  13. [1,1′-Bis(diphenylphosphinoferrocene]carbonyl[dihydrobis(pyrazol-1-ylborato]hydridoruthenium(II acetone solvate

    Directory of Open Access Journals (Sweden)

    Alan J. Lough

    2008-12-01

    Full Text Available In the title compound, [FeRu(C17H14P2(C6H8BN4H(CO]·C3H6O, the RuII ion is coordinated in a distorted octahedral environment involving a hydride ligand, a carbonyl ligand and two bidentate ligands. Of the two bidentate ligands, the bulky 1,1′-bis(diphenylphosphinoferrocene (dppf ligand chelates with a larger bite angle of 101.90 (2°, whereas the bite angle of the [H2Bpz2]− ligand (pz = pyrazolyl is 85.67 (7°. The latter ligand creates an RuN4B six-membered ring with a boat conformation, which puckers towards the site of the small hydride ligand. The hydride ligand is cis with respect to the carbonyl ligand and trans to one of the P atoms of the dppf ligand. In the crystal structure, there are weak intermolecular C—H...O hydrogen bonds between complex molecules and acetone solvent molecules.

  14. Phlorotannins from brown algae (Fucus vesiculosus) inhibited the formation of advanced glycation endproducts by scavenging reactive carbonyls.

    Science.gov (United States)

    Liu, Haiyan; Gu, Liwei

    2012-02-08

    Accumulation of advanced glycation end products (AGEs) in vivo is associated with aging, diabetes, Alzheimer's disease, renal failure, etc. The objective of this study was to investigate the inhibitory effects of brown algae Fucus vesiculosus phlorotannins on the formation of AGEs. F. vesiculosus phlorotannins were extracted using 70% acetone. The resultant extract was fractionated into dichloromethane, ethyl acetate, butanol, and water fractions. The ethyl acetate fraction was further fractionated into four subfractions (Ethyl-F1 to -F4) using a Sephadex LH-20 column. F. vesiculosus acetone extract or fractions significantly inhibited the formation of AGEs mediated by glucose and methylglyoxal in a concentration-dependent manner. The concentrations of F. vesiculosus extracts required to inhibit 50% of albumin glycation (EC(50)) in the bovine serum albumin (BSA)-methylglyoxal assay were lower than those of aminoguanidine (a drug candidate for diabetic complication), except for F. vesiculosus acetone extract and dichloromethane fraction. In the BSA-glucose assay, F. vesiculosus extracts inhibited BSA glycation more than or as effectively as aminoguanidine, except for Ethyl-F3 and -F4. The ethyl acetate fraction and its four subfractions scavenged more than 50% of methylglyoxal in two hours. The hypothesis whether F. vesiculosus phlorotannins scavenged reactive carbonyls by forming adducts was tested. Phloroglucinol, the constituent unit of phlorotannins, reacted with glyoxal and methylglyoxal. Five phloroglucinol-carbonyl adducts were detected and tentatively identified using HPLC-ESI-MS(n).

  15. Soil atmosphere exchange of carbonyl sulfide (COS regulated by diffusivity depending on water-filled pore space

    Directory of Open Access Journals (Sweden)

    H. Van Diest

    2008-04-01

    Full Text Available The exchange of carbonyl sulfide (COS between soil and the atmosphere was investigated for three arable soils from Germany, China and Finland and one forest soil from Siberia for parameterization in the relation to ambient carbonyl sulfide (COS concentration, soil water content (WC and air temperature. All investigated soils acted as sinks for COS. A clear and distinct uptake optimum was found for the German, Chinese, Finnish and Siberian soils at 11.5%, 9%, 11.5%, and 9% soil WC, respectively, indicating that the soil WC acts as an important biological and physical parameter for characterizing the exchange of COS between soils and the atmosphere. Different optima of deposition velocities (Vd as observed for the Chinese, Finnish and Siberian boreal soil types in relation to their soil WC, aligned at 19% in relation to the water-filled pore space (WFPS, indicating the dominating role of gas diffusion. This interpretation was supported by the linear correlation between Vd and bulk density. We suggest that the uptake of COS depends on the diffusivity dominated by WFPS, a parameter depending on soil WC, soil structure and porosity of the soil.

  16. A mechanistic investigation into the elimination of phosphonium salts from rhodium-TRIPHOS complexes under methanol carbonylation conditions.

    Science.gov (United States)

    Lamb, Gareth W; Clarke, Matthew L; Slawin, Alexandra M Z; Williams, Bruce

    2008-09-28

    Phosphine modified rhodium complexes are currently the topic of considerable research as methanol carbonylation catalysts, but often suffer from poor stability. This paper reports on an investigation into how coordination mode affects the elimination of phosphonium salts from rhodium complexes, namely [trans-RhCl(CO)(PPh3)2] 1, [RhCl(CO)(dppe)] 2, [RhCl(CO)(dppb)]2 3, [Rh(TRIPHOS)(CO)2]Cl 4. These complexes are all potential pre-catalysts for methanol carbonylation. The reaction of these complexes with methyl iodide at 140 degrees C under both N2 and CO atmospheres has been studied and has revealed clear differences in the stability of the corresponding Rh(III) complexes. In contrast to both monomeric 2 and dimeric 3 that react cleanly with CH3I to give stable Rh(III) acetyl complexes, 4 forms a novel bidentate complex after the elimination of the one arm of the ligand as a quaternised phosphonium salt. The structure of this complex has been determined spectroscopically and using X-ray crystallography. The mechanism of formation of this novel complex has been investigated using 13CH3I and strong evidence that supports a dissociative mechanism as the means of phosphine loss from the rhodium centre is provided.

  17. Hierarchical on-surface synthesis and electronic structure of carbonyl-functionalized one- and two-dimensional covalent nanoarchitectures

    Science.gov (United States)

    Steiner, Christian; Gebhardt, Julian; Ammon, Maximilian; Yang, Zechao; Heidenreich, Alexander; Hammer, Natalie; Görling, Andreas; Kivala, Milan; Maier, Sabine

    2017-03-01

    The fabrication of nanostructures in a bottom-up approach from specific molecular precursors offers the opportunity to create tailored materials for applications in nanoelectronics. However, the formation of defect-free two-dimensional (2D) covalent networks remains a challenge, which makes it difficult to unveil their electronic structure. Here we report on the hierarchical on-surface synthesis of nearly defect-free 2D covalent architectures with carbonyl-functionalized pores on Au(111), which is investigated by low-temperature scanning tunnelling microscopy in combination with density functional theory calculations. The carbonyl-bridged triphenylamine precursors form six-membered macrocycles and one-dimensional (1D) chains as intermediates in an Ullmann-type coupling reaction that are subsequently interlinked to 2D networks. The electronic band gap is narrowed when going from the monomer to 1D and 2D surface-confined π-conjugated organic polymers comprising the same building block. The significant drop of the electronic gap from the monomer to the polymer confirms an efficient conjugation along the triphenylamine units within the nanostructures.

  18. Sulfur isotopic fractionation of carbonyl sulfide during degradation by soil bacteria and enzyme

    Science.gov (United States)

    Kamezaki, Kazuki; Hattori, Shohei; Ogawa, Takahiro; Toyoda, Sakae; Kato, Hiromi; Katayama, Yoko; Yoshida, Naohiro

    2017-04-01

    Carbonyl sulfide (COS) is an atmospheric trace gas that possess great potential for tracer of carbon cycle (Campbell et al., 2008). COS is taken up by vegetation during photosynthesis like absorption of carbon dioxide but COS can not emit by respiration of vegetation, suggesting possible tracer for gross primary production. However, some studies show the COS-derived GPP is larger than the estimates by using carbon dioxide flux because COS flux by photolysis and soil flux are not distinguished (e.g. Asaf et al., 2013). Isotope analysis is a useful tool to trace sources and transformations of trace gases. Recently our group developed a promising new analytical method for measuring the stable sulfur isotopic compositions of COS using nanomole level samples: the direct isotopic analytical technique of on-line gas chromatography-isotope ratio mass spectrometry (GC-IRMS) using fragmentation ions S+ enabling us to easily analyze sulfur isotopes in COS (Hattori et al., 2015). Soil is thought to be important as both a source and a sink of COS in the troposphere. In particular, soil has been reported as a large environmental sink for atmospheric COS. Bacteria isolated from various soils actively degrade COS, with various enzymes such as carbonic anhydrase and COSase (Ogawa et al., 2013) involved in COS degradation. However, the mechanism and the magnitude of bacterial contribution in terms of a sink for atmospheric COS is still uncertain. Therefore, it is important to quantitatively evaluate this contribution using COS sulfur isotope analysis. We present isotopic fractionation constants for COS by laboratory incubation experiments during degradation by soil bacteria and COSase. Incubation experiments were conducted using strains belonging to the genera Mycobacterium, Williamsia, Cupriavidus, and Thiobacillus, isolated from natural soil or activated sludge and enzyme purified from a bacteria. As a result, the isotopic compositions of OCS were increased during degradation of

  19. On-road emissions of carbonyls from vehicles powered by biofuel blends in traffic tunnels in the Metropolitan Area of Sao Paulo, Brazil

    Science.gov (United States)

    Nogueira, Thiago; Souza, Kely Ferreira de; Fornaro, Adalgiza; Andrade, Maria de Fatima; Carvalho, Lilian Rothschild Franco de

    2015-05-01

    On-road emissions of carbonyls from the current vehicle fleet of Brazil were determined in two experimental campaigns, conducted in traffic tunnels located in the Metropolitan Area of São Paulo (MASP), in southeastern Brazil. Among carbonyl species, formaldehyde and acetaldehyde were the most abundant in all sampling periods. In Brazil, heavy-duty vehicles (HDVs) run on a blend of 95% regular diesel/5% biodiesel from soy, whereas light-duty vehicles (LDVs) run on gasohol (75-80% gasoline/20-25% ethanol) or hydrous ethanol. We found that HDVs showed the highest overall carbonyl emissions, although LDVs were responsible for high emissions of acetaldehyde. In comparison with LDVs in California, which are powered by 90% gasoline/10% ethanol, LDVs in Brazil were found to emit 352% and 263% more formaldehyde and acetaldehyde.

  20. A High Resolution/Accurate Mass (HRAM) Data-Dependent MS3 Neutral Loss Screening, Classification, and Relative Quantitation Methodology for Carbonyl Compounds in Saliva

    Science.gov (United States)

    Dator, Romel; Carrà, Andrea; Maertens, Laura; Guidolin, Valeria; Villalta, Peter W.; Balbo, Silvia

    2017-04-01

    Reactive carbonyl compounds (RCCs) are ubiquitous in the environment and are generated endogenously as a result of various physiological and pathological processes. These compounds can react with biological molecules inducing deleterious processes believed to be at the basis of their toxic effects. Several of these compounds are implicated in neurotoxic processes, aging disorders, and cancer. Therefore, a method characterizing exposures to these chemicals will provide insights into how they may influence overall health and contribute to disease pathogenesis. Here, we have developed a high resolution accurate mass (HRAM) screening strategy allowing simultaneous identification and relative quantitation of DNPH-derivatized carbonyls in human biological fluids. The screening strategy involves the diagnostic neutral loss of hydroxyl radical triggering MS3 fragmentation, which is only observed in positive ionization mode of DNPH-derivatized carbonyls. Unique fragmentation pathways were used to develop a classification scheme for characterizing known and unanticipated/unknown carbonyl compounds present in saliva. Furthermore, a relative quantitation strategy was implemented to assess variations in the levels of carbonyl compounds before and after exposure using deuterated d 3 -DNPH. This relative quantitation method was tested on human samples before and after exposure to specific amounts of alcohol. The nano-electrospray ionization (nano-ESI) in positive mode afforded excellent sensitivity with detection limits on-column in the high-attomole levels. To the best of our knowledge, this is the first report of a method using HRAM neutral loss screening of carbonyl compounds. In addition, the method allows simultaneous characterization and relative quantitation of DNPH-derivatized compounds using nano-ESI in positive mode.

  1. Improved sample preparation and rapid UHPLC analysis of SO2 binding carbonyls in wine by derivatisation to 2,4-dinitrophenylhydrazine.

    Science.gov (United States)

    Jackowetz, J N; Mira de Orduña, R

    2013-08-15

    Sulphur dioxide (SO2) is essential for the preservation of wines. The presence of SO2 binding compounds in musts and wines may limit sulphite efficacy leading to higher total SO2 additions, which may exceed SO2 limits permitted by law and pose health risks for sensitive individuals. An improved method for the quantification of significant wine SO2 binding compounds is presented that applies a novel sample treatment approach and rapid UHPLC separation. Glucose, galacturonic acid, alpha-ketoglutarate, pyruvate, acetoin and acetaldehyde were derivatised with 2,4-dinitrophenylhydrazine and separated using a solid core C18 phase by ultra high performance liquid chromatography. Addition of EDTA to samples prevented de novo acetaldehyde formation from ethanol oxidation. Optimised derivatisation duration enhanced reproducibility and allowed for glucose and galacturonic acid quantification. High glucose residues were found to interfere with the recovery of other SO2 binders, but practical SO2 concentrations and red wine pigments did not affect derivatisation efficiency. The calibration range, method accuracy, precision and limits of detection were found to be satisfactory for routine analysis of SO2 binders in wines. The current method represents a significant improvement in the comprehensive analysis of SO2 binding wine carbonyls. It allows for the quantification of major SO2 binders at practical analyte concentrations, and uses a simple sample treatment method that prevents treatment artifacts. Equipment utilisation could be reduced by rapid LC separation while maintaining analytical performance parameters. The improved method will be a valuable addition for the analysis of total SO2 binder pools in oenological samples. Published by Elsevier Ltd.

  2. Infrared and microwave spectra of the acetylene-ammonia and carbonyl sulfide-ammonia complexes: a comparative study of a weak C-H···N hydrogen bond and an S···N bond.

    Science.gov (United States)

    Liu, Xunchen; Xu, Yunjie

    2011-08-21

    We report a combined high resolution infrared and microwave spectroscopic investigation of the acetylene-ammonia and carbonyl sulfide-ammonia complexes using a pulsed slit-nozzle multipass absorption spectrometer based on a quantum cascade laser and a pulsed nozzle beam Fourier transform microwave spectrometer, respectively. The ro-vibrational transitions of the acetylene-ammonia complex have been measured at 6 μm in the vicinity of the ν(4) band of ammonia for the first time. The previously reported pure rotational transitions have been extended to higher J and K values with (14)N nuclear quadrupole hyperfine components detected and analyzed. The spectral analysis reveals that acetylene binds to ammonia through a C-H···N weak hydrogen bond to form a C(3v) symmetric top, consistent with the previous microwave [Fraser et al., J. Chem. Phys., 1984, 80, 1423] and infrared spectroscopic study at 3 μm [Hilpert et al., J. Chem. Phys., 1996, 105, 6183]. A parallel study has also been carried out for the carbonyl sulfide-ammonia complex whose pure rotational and ro-vibrational spectra at 6 μm have been detected and analyzed for the first time. The spectral and the subsequent structural analyses, in conjunction with the corresponding ab initio calculation, indicate that the OCS-NH(3) complex assumes C(3v) symmetry with S pointing to N of NH(3), in contrast to the T-shaped geometries obtained for the isoelectronic N(2)O-NH(3) and CO(2)-NH(3) complexes.

  3. Effect of pretreatment temperature on catalytic performance of the catalysts derived from cobalt carbonyl cluster in Fischer-Tropsch Synthesis

    Directory of Open Access Journals (Sweden)

    Byambasuren O

    2017-02-01

    Full Text Available The monometallic cobalt-based catalysts were prepared by pretreating the catalysts derived from carbonyl cluster precursor (CO6Co2CC(COOH2 supported on γ-Al2O3 with hydrogen at 180, 220, and 260°C respectively. The temperature effect of the pretreatments on the structure evolution of cluster precursors and the catalytic performance of the Fischer-Tropsch (F-T synthesis was investigated. The pretreated catalyst at 220°C with unique phase structure exhibited best catalytic activity and selectivity among three pretreated catalysts. Moreover, the catalysts exhibited high dispersion due to the formation of hydrogen bonds between the cluster precursor and γ-Al2O3 support.

  4. Supported Single-Site Ti(IV) on a Metal–Organic Framework for the Hydroboration of Carbonyl Compounds

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Zhiyuan [College; amp, Molecular Sciences, Institute of Advanced Studies, Wuhan University, Wuhan 430072, PR China; Chemical; amp, Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States; Liu, Dong [College; amp, Molecular Sciences, Institute of Advanced Studies, Wuhan University, Wuhan 430072, PR China; Chemical; amp, Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States; Camacho-Bunquin, Jeffrey [Chemical; amp, Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States; Zhang, Guanghui [Department; Yang, Dali [College; amp, Molecular Sciences, Institute of Advanced Studies, Wuhan University, Wuhan 430072, PR China; Chemical; amp, Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States; López-Encarnación, Juan M. [Chemical; amp, Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States; Department; Xu, Yunjie [Department; Ferrandon, Magali S. [Chemical; amp, Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States; Niklas, Jens [Chemical; amp, Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States; Poluektov, Oleg G. [Chemical; amp, Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States; Jellinek, Julius [Chemical; amp, Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States; Lei, Aiwen [College; amp, Molecular Sciences, Institute of Advanced Studies, Wuhan University, Wuhan 430072, PR China; Chemical; amp, Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States; Bunel, Emilio E. [Chemical; amp, Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States; Delferro, Massimiliano [Chemical; amp, Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States

    2017-10-10

    ABSTRACT: A stable and structurally well-defined titanium alkoxide catalyst supported on a metal-organic-framework (MOF) of UiO-67 topology (ANL1-Ti(OiPr)2) was synthesized and fully characterized by a variety of analytical and spectroscopic techniques, including BET, TGA, PXRD, XAS, DRIFT, SEM, and DFT computations. The Ti-functionalized MOF was demonstrated active for the catalytic hydroboration of a wide range of aldehydes and ketones with HBpin as the boron source. Compared to traditional homogeneous and supported hydroboration catalysts, ANL1-Ti(OiPr)2 is completely recyclable and reusable, making it a promising hydroboration catalyst alternative for green and sustainable chemical synthesis. DFT calculations suggest that the catalytic hydroboration proceeds via a (1) hydride transfer between the active Ti-hydride species and a carbonyl moiety (rate determining step), and (2) alkoxide transfer (intramolecular σ-bond metathesis) to generate the boronate ester product.

  5. Carbonyl(N-nitroso-N-oxido-1-naphtylamine-κ2O,O′(triphenylphosphine-κPrhodium(I acetone solvate

    Directory of Open Access Journals (Sweden)

    T. J. Muller

    2009-12-01

    Full Text Available The title compound, [Rh(C10H7N2O2(C18H15P(CO]·(CH32CO, is the second structural report of a metal complex formed with the O,O′-C10H7N2O2 (neocupferrate ligand. In the crystal structure, the metal centre is surrounded by one carbonyl ligand, one triphenylphosphine ligand and the bidentate neocupferrate ligand, forming a distorted square-planar RhCO2P coordination set which is best illustrated by the small O—Rh—O bite angle of 77.74 (10°. There are no classical hydrogen-bond interactions observed for this complex.

  6. Carbon-carbon bond-forming reactions of α-thioaryl carbonyl compounds for the synthesis of complex heterocyclic molecules.

    Science.gov (United States)

    Biggs-Houck, James E; Davis, Rebecca L; Wei, Jingqiang; Mercado, Brandon Q; Olmstead, Marilyn M; Tantillo, Dean J; Shaw, Jared T

    2012-01-06

    Strategies for the formation of carbon-carbon bonds from the α-thioaryl carbonyl products of substituted lactams are described. Although direct functionalization is possible, a two step process of oxidation and magnesium-sulfoxide exchange has proven optimal. The oxidation step results in the formation of two diastereomers that exhibit markedly different levels of stability toward elimination, which is rationalized on the basis of quantum mechanical calculations and X-ray crystallography. Treatment of the sulfoxide with i-PrMgCl results in the formation of a magnesium enolate that will undergo an intramolecular Michael addition reaction to form two new stereogenic centers. The relationship between the substitution patterns of the sulfoxide substrate and the efficiency of the magnesium exchange reaction are also described.

  7. Globalisation and Higher Education

    NARCIS (Netherlands)

    Marginson, Simon; van der Wende, Marijk

    2007-01-01

    Economic and cultural globalisation has ushered in a new era in higher education. Higher education was always more internationally open than most sectors because of its immersion in knowledge, which never showed much respect for juridical boundaries. In global knowledge economies, higher education

  8. India's Higher Education Challenges

    Science.gov (United States)

    Altbach, Philip G.

    2014-01-01

    India, with the world's second largest higher education system and a rapidly growing economy as one of the BRIC nations, faces significant challenges in building both capacity and excellence in higher education. India's higher education system is characterized by "islands of excellence in a sea of mediocrity." The mainstream universities…

  9. Facile preparation and enhanced microwave absorption properties of flake carbonyl iron/Fe{sub 3}O{sub 4} composite

    Energy Technology Data Exchange (ETDEWEB)

    Min, Dandan, E-mail: mdd4776@126.com; Zhou, Wancheng; Luo, Fa; Zhu, Dongmei

    2017-08-01

    Highlights: • Flake carbonyl iron/Fe{sub 3}O{sub 4} composites were prepared by surface oxidation technique. • Lower permittivity and modest permeability was obtained by the FCI/Fe{sub 3}O{sub 4} composites. • Enhanced absorption efficiency and broader absorption band were obtained. - Abstract: Flake carbonyl iron/Fe{sub 3}O{sub 4} (FCI/Fe{sub 3}O{sub 4}) composites with enhanced microwave absorption properties were prepared by a direct and flexible surface oxidation technique. The phase structures, morphology, magnetic properties, frequency-dependent electromagnetic and microwave absorption properties of the composites were investigated. The measurement results showed that lower permittivity as well as modest permeability was obtained by the FCI/Fe{sub 3}O{sub 4} composites. The calculated microwave absorption properties indicated that enhanced absorption efficiency and broader absorption band were obtained by the FCI/Fe{sub 3}O{sub 4} composite comparing with the FCI composite. The absorption frequency range with reflection loss (RL) below −5 dB of FCI/Fe{sub 3}O{sub 4} composites at reaction time of 90 min at thickness of 1.5 mm is 13.3 GHz from 4.7 to 18 GHz, while the bandwidth of the FCI composite is only 5.9 GHz from 2.6 to 8.5 GHz at the same thickness. Thus, such absorbers could act as effective and wide broadband microwave absorbers in the GHz range.

  10. Metal carbonyl-hydrosilane reactions and hydrosilation catalysis. Final report for period May 1, 1995 - August 14, 1999

    Energy Technology Data Exchange (ETDEWEB)

    Cutler, Alan R.

    2001-04-14

    Manganese carbonyl complexes serve as hydrosilation precatalysts for selectively transforming a carbonyl group into a doxy methylene or a fully reduced methylene group. Substrates of interest include (1) aldehydes, ketones, carboxylic acids, silyl esters, and esters, and (2) their organometallic acyl counterparts. Two types of manganese precatalysts have been reported: (a) alkyl and acyl complexes (L)(CO){sub 4}MnR [L = CO, PPh{sub 3}; R = COCH{sub 3}, COPh, CH{sub 3}] and (b) halides (CO){sub 5}MnX and [(CO){sub 4}MnX]{sub 2} (X = Br, I). The former promote hydrosilation and deoxygenation catalysis; the latter promote dehydrogenative silation of alcohols and carboxylic acids as well as hydrosilation and deoxygenation of some metallocarboxylic acid derivatives. In every case studied, these Mn precatalysts are far more reactive or selective than traditional Rh(l) precatalysts. The reaction chemistry of the above and other Mn alkyl complexes with hydrosilanes was studied in order to probe catalysis mechanism(s). Thus, Mn(CO){sub 5} methyl, benzyl, acetyl, and benzoyl (4 p-substituents) complexes reacted with hydrosilines by four different mechanisms, which were established. A noteworthy development was that the methyl and benzoyl complexes gave moderate yields of a new ({eta}{sup 2}-Si-H) silane adduct (CO){sub 4}Mn(SiMe{sub 2}Ph)(H-SiMe{sub 2}Ph), which is stable in the presence of excess silane. This silane adduct promotes all three catalytic reactions; its extraordinary activity and potential selectivity are under study.

  11. Analysis of protein oxidation in serum of fetal and newborn piglets and the influence of iron dextran on induction of protein carbonyls.

    Science.gov (United States)

    Methods were employed to evaluate serum biomarkers associated with protein oxidative stress and damage, to determine potential sources of metabolic stress in baby pigs. Protein carbonyls in serum were converted to dinitrophenyl (DNP) derivatives with DNP-hydrazine, precipitated with TCA, extracted i...

  12. Al(HSO{sub 4}){sub 3} as an efficient catalyst for acetalization of carbonyl compounds under heterogeneous or solvent-free conditions

    Energy Technology Data Exchange (ETDEWEB)

    Mirjalili, BiBi Fatemeh; Hazar, Azizeh [Yazd University, Yazd (Iran, Islamic Republic of). College of Science. Dept. of Chemistry]. E-mail: fmirjalili@yazduni.ac.ir; Zolfigol, Mohammad Ali [Bu-Ali Sina University, Hamadan (Iran, Islamic Republic of). College of Science. Dept. of Chemistry; Bamoniri, Abdolhamid [Kashan University, Kashan (Iran, Islamic Republic of). College of Science. Dept. of Chemistry

    2005-07-15

    Al(HSO{sub 4}){sub 3} as a solid acid was applied for acetalization of carbonyl compounds at room temperature and under solvent-free conditions with good to excellent yields. The cheapness and availability of this reagent with easy procedure and work-up make this method attractive for the organic synthesis. (author)

  13. On the mechanism of the copper-catalyzed enantioselective 1,4-addition of grignard reagents to alpha,beta-unsaturated carbonyl compounds

    NARCIS (Netherlands)

    Harutyunyan, Syuzanna R.; Lopez, Fernando; Browne, Wesley R.; Correa, Arkaitz; Pena, Diego; Badorrey, Ramon; Meetsma, Auke; Minnaard, Adriaan J.; Feringa, Ben L.; Lo´pez, F.; Pen~a, D.

    2006-01-01

    The mechanism of the enantioselective 1,4-addition of Grignard reagents to alpha,beta-unsaturated carbonyl compounds promoted by copper complexes of chiral ferrocenyl diphosphines is explored through kinetic, spectroscopic, and electrochemical analysis. On the basis of these studies, a structure of

  14. Substituent Effects in the Noncovalent Bonding of SO2 to Molecules Containing a Carbonyl Group. The Dominating Role of the Chalcogen Bond.

    Science.gov (United States)

    Azofra, Luis Miguel; Scheiner, Steve

    2014-05-29

    The SO2 molecule is paired with a number of carbonyl-containing molecules, and the properties of the resulting complexes are calculated by high-level ab initio theory. The global minimum of each pair is held together primarily by a S···O chalcogen bond wherein the lone pairs of the carbonyl O transfer charge to the π* antibonding SO orbital, supplemented by smaller contributions from weak CH···O H-bonds. The binding energies vary between 4.2 and 8.6 kcal/mol, competitive with even some of the stronger noncovalent forces such as H-bonds and halogen bonds. The geometrical arrangement places the carbonyl O atom above the plane of the SO2 molecule, consistent with the disposition of the molecular electrostatic potentials of the two monomers. This S···O bond differs from the more commonly observed chalcogen bond in both geometry and origin. Substituents exert their influence via inductive effects that change the availability of the carbonyl O lone pairs as well as the intensity of the negative electrostatic potential surrounding this atom.

  15. Dormancy removal of apple seeds by cold stratification is associated with fluctuation in H2O2, NO production and protein carbonylation level.

    Science.gov (United States)

    Dębska, Karolina; Krasuska, Urszula; Budnicka, Katarzyna; Bogatek, Renata; Gniazdowska, Agnieszka

    2013-03-15

    Reactive oxygen (ROS) and nitrogen (RNS) species play a signaling role in seed dormancy alleviation and germination. Their action may be described by the oxidative/nitrosative "window/door". ROS accumulation in embryos could lead to oxidative modification of protein through carbonylation. Mature apple (Malus domestica Borkh.) seeds are dormant and do not germinate. Their dormancy may be overcome by 70-90 days long cold stratification. The aim of this work was to analyze the relationship between germinability of embryos isolated from cold (5°C) or warm (25°C) stratified apple seeds and ROS or nitric oxide (NO) production and accumulation of protein carbonyl groups. A biphasic pattern of variation in H2O2 concentration in the embryos during cold stratification was detected. H2O2 content increased markedly after 7 days of seeds imbibition at 5°C. After an additional two months of cold stratification, the H2O2 concentration in embryos reached the maximum. NO production by the embryos was low during entire period of stratification, but increased significantly in germination sensu stricto (i.e. phase II of the germination process). The highest content of protein carbonyl groups was detected after 6 weeks of cold stratification treatment. Fluctuation of H2O2 and protein carbonylation seems to play a pivotal role in seed dormancy alleviation by cold stratification, while NO appears to be necessary for seed germination. Copyright © 2012 Elsevier GmbH. All rights reserved.

  16. Chemoselective Reductive Amination of Carbonyl Compounds for the Synthesis of Tertiary Amines Using SnCl2·2H2O/PMHS/MeOH.

    Science.gov (United States)

    Nayal, Onkar S; Bhatt, Vinod; Sharma, Sushila; Kumar, Neeraj

    2015-06-05

    Stannous chloride catalyzed chemoselective reductive amination of a variety of carbonyl compounds with aromatic amines has been developed for the synthesis of a diverse range of tertiary amines using inexpensive polymethylhydrosiloxane as reducing agent in methanol. The present method is also applicable for the synthesis of secondary amines including heterocyclic ones.

  17. [Higher Brain Dysfunction].

    Science.gov (United States)

    Kashima, Haruo

    2015-01-01

    The technical term "higher brain dysfunction" is used widely in Japan. However, it is not always clear what "higher" means. The author thinks that the term "higher" is understood as being associated with a meaning. In this article, the differences between higher brain dysfunctions and elementary brain dysfunctions are discussed from the point of view of lesion localization and the consistency of symptoms. The psychiatric approach is indispensable for the assessment of higher brain dysfunction. A simple test for mild Alzheimer-type dementia is also introduced.

  18. Higher derivative mimetic gravity

    Science.gov (United States)

    Gorji, Mohammad Ali; Mansoori, Seyed Ali Hosseini; Firouzjahi, Hassan

    2018-01-01

    We study cosmological perturbations in mimetic gravity in the presence of classified higher derivative terms which can make the mimetic perturbations stable. We show that the quadratic higher derivative terms which are independent of curvature and the cubic higher derivative terms which come from curvature corrections are sufficient to remove instabilities in mimetic perturbations. The classified higher derivative terms have the same dimensions but they contribute differently in the background and perturbed equations. Therefore, we can control both the background and the perturbation equations allowing us to construct the higher derivative extension of mimetic dark matter and the mimetic nonsingular bouncing scenarios. The latter can be thought as a new higher derivative effective action for the loop quantum cosmology scenario in which the equations of motion coincide with those suggested by loop quantum cosmology. We investigate a possible connection between the mimetic cosmology and the Randall-Sundrum cosmology.

  19. Higher Spin Matrix Models

    Directory of Open Access Journals (Sweden)

    Mauricio Valenzuela

    2017-10-01

    Full Text Available We propose a hybrid class of theories for higher spin gravity and matrix models, i.e., which handle simultaneously higher spin gravity fields and matrix models. The construction is similar to Vasiliev’s higher spin gravity, but part of the equations of motion are provided by the action principle of a matrix model. In particular, we construct a higher spin (gravity matrix model related to type IIB matrix models/string theory that have a well defined classical limit, and which is compatible with higher spin gravity in A d S space. As it has been suggested that higher spin gravity should be related to string theory in a high energy (tensionless regime, and, therefore to M-Theory, we expect that our construction will be useful to explore concrete connections.

  20. Higher dimensional higher derivative ϕ4 theory

    Science.gov (United States)

    Gracey, J. A.; Simms, R. M.

    2017-07-01

    We construct several towers of scalar quantum field theories with an O (N ) symmetry which have higher derivative kinetic terms. The Lagrangians in each tower are connected by lying in the same universality class at the d -dimensional Wilson-Fisher fixed point. Moreover the universal theory is studied using the large N expansion and we determine d -dimensional critical exponents to O (1 /N2). We show that these new universality classes emerge naturally as solutions to the linear relation of the dimensions of the fields deduced from the underlying force-matter interaction of the universal critical theory. To substantiate the equivalence of the Lagrangians in each tower we renormalize each to several loop orders and show that the renormalization group functions are consistent with the large N critical exponents. While we focus on the first two new towers of theories and renormalize the respective Lagrangians to 16 and 18 dimensions there are an infinite number of such towers. We also briefly discuss the conformal windows and the extension of the ideas to theories with spin-1/2 and spin-1 fields as well as the idea of lower dimension completeness.

  1. Cost in Higher Education

    Science.gov (United States)

    2007-06-01

    standardize methodology and accountability used nationwide by institutions of higher education . The aim is to review existing cost criteria and procedures...task. The objective of this research is to look into the cost structure used presently by two institutions of higher education , namely the Naval

  2. Higher Education in California

    Science.gov (United States)

    Public Policy Institute of California, 2016

    2016-01-01

    Higher education enhances Californians' lives and contributes to the state's economic growth. But population and education trends suggest that California is facing a large shortfall of college graduates. Addressing this short­fall will require strong gains for groups that have been historically under­represented in higher education. Substantial…

  3. Reputation in Higher Education

    DEFF Research Database (Denmark)

    Plewa, Carolin; Ho, Joanne; Conduit, Jodie

    2016-01-01

    Reputation is critical for institutions wishing to attract and retain students in today's competitive higher education setting. Drawing on the resource based view and configuration theory, this research proposes that Higher Education Institutions (HEIs) need to understand not only the impact...

  4. Happiness in Higher Education

    Science.gov (United States)

    Elwick, Alex; Cannizzaro, Sara

    2017-01-01

    This paper investigates the higher education literature surrounding happiness and related notions: satisfaction, despair, flourishing and well-being. It finds that there is a real dearth of literature relating to profound happiness in higher education: much of the literature using the terms happiness and satisfaction interchangeably as if one were…

  5. Reimagining Christian Higher Education

    Science.gov (United States)

    Hulme, E. Eileen; Groom, David E., Jr.; Heltzel, Joseph M.

    2016-01-01

    The challenges facing higher education continue to mount. The shifting of the U.S. ethnic and racial demographics, the proliferation of advanced digital technologies and data, and the move from traditional degrees to continuous learning platforms have created an unstable environment to which Christian higher education must adapt in order to remain…

  6. Consumerism in Higher Education

    Science.gov (United States)

    Green, Mark

    1973-01-01

    In considering consumerism in higher education, the student becomes the consumer,'' the university the corporation,'' and higher education the education industry.'' Other members of the education fraternity become investors, management, workers, direct consumers, and indirect consumers. This article proposes that it behooves the student to…

  7. Analysis of Selected Carbonyl Compounds in Tobacco Samples by Using Pentafluorobenzylhydroxylamine Derivatization and Gas Chromatography-Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Bao Mingliang

    2014-09-01

    Full Text Available Nous avons mis au point une méthode, à la fois fiable, précise et simple, d’analyse courante des composés carbonylés, en ce compris le formaldéhyde, l’acétaldéhyde, l’acétone, le propionaldéhyde, la méthyléthylcétone (MEC, le butyraldéhyde et le crotonaldéhyde, présents à l’état de traces dans les produits de tabac ouvré. Un échantillon d’un gramme de tabac, additionné d’un mélange de carbonyles marqués d’un isotope en guise de normes internes, a été extrait par l’eau. Une part de l’extrait aqueux a subi un processus de dérivatisation à l’aide de chlorhydrate d’o-(2,3,4,5,6-pentafluorobenzyle-hydroxylamine (PFBHA. Les dérivés carbonylés obtenus à l’aide du PFBHA ont ensuite été extraits par l’hexane et analysés par chromatographie en phase gazeuse couplée à la spectrométrie de masse (GC-MS. La précision et l’exactitude de la méthode ont été évaluées au regard d’une cigarette de référence Kentucky « additionnée » 3R4F et de produits de référence sans fumée CORESTA CRP1, CRP2, CRP3 et CRP4. Eu égard aux composés carbonylés analysés, d’excellents taux de précision (5-10% et de récupération (95-107% ont été observés avec divers produits du tabac « additionnés », à l’exception de l’acroléine, qui s’est avérée instable dans tous les produits du tabac testés. L’intervalle linéaire de la méthode mise au point s’est étendu de 0,07 à 36 μg/g avec des limites de quantification variant de 0,10 à 0,15 μg/g. Grâce à la présente méthode, le formaldéhyde (0,31-6,24 μg/g et l’acétaldéhyde (0,84- 17,7 μg/g ont été décelés dans tous les produits de référence testés. L’acétone (0,55-2,12 μg/g a été trouvée dans les produits 3R4F, CRP1, CRP2 et CRP3. Des niveaux décelables de propionaldéhyde n’ont été observés que dans les produits CRP1 et CRP3. Les niveaux de MEC, butyraldéhyde et crotonaldéhyde décelés dans tous

  8. Quality of Higher Education

    DEFF Research Database (Denmark)

    Zou, Yihuan

    is about constructing a more inclusive understanding of quality in higher education through combining the macro, meso and micro levels, i.e. from the perspectives of national policy, higher education institutions as organizations in society, individual teaching staff and students. It covers both......Quality in higher education was not invented in recent decades – universities have always possessed mechanisms for assuring the quality of their work. The rising concern over quality is closely related to the changes in higher education and its social context. Among others, the most conspicuous...... changes are the massive expansion, diversification and increased cost in higher education, and new mechanisms of accountability initiated by the state. With these changes the traditional internally enacted academic quality-keeping has been given an important external dimension – quality assurance, which...

  9. Higher English for CFE

    CERN Document Server

    Bridges, Ann; Mitchell, John

    2015-01-01

    A brand new edition of the former Higher English: Close Reading , completely revised and updated for the new Higher element (Reading for Understanding, Analysis and Evaluation) - worth 30% of marks in the final exam!. We are working with SQA to secure endorsement for this title. Written by two highly experienced authors this book shows you how to practice for the Reading for Understanding, Analysis and Evaluation section of the new Higher English exam. This book introduces the terms and concepts that lie behind success and offers guidance on the interpretation of questions and targeting answer

  10. Origins of n-alkanes, carbonyl compounds and molecular biomarkers in atmospheric fine and coarse particles of Athens, Greece.

    Science.gov (United States)

    Andreou, G; Rapsomanikis, S

    2009-10-15

    The abundance and origin of aliphatic hydrocarbons, carbonyl compounds and molecular biomarkers found in the aliphatic fraction of PM(10-2.5) and PM(2.5) in the centre of Athens Greece are discussed in an attempt to reveal seasonal air pollution characteristics of the conurbation. Each extract was fractionated into individual compound classes and was analyzed using gas chromatography coupled to mass spectrometry. Normal alkanes, ranging from C(14) to C(35), were abundant in PM(10-2.5) and PM(2.5) samples during both sampling campaigns. The daily concentration of total n-alkanes was up to 438 ng m(-3) for PM(10-2.5) and up to 511 ng m(-3) for PM(2.5). Additionally, gaseous concentrations of n-alkanes were calculated, revealing that the relative proportions between gaseous and particle phases of individual compounds may differ significantly between summer and late winter. Normal alkanals and alkan-2-ones were only detected in the fine fraction of particulate matter and their concentrations were much lower than the n-alkane concentrations. Several geochemical parameters were used to qualitatively reconcile the sources of organic aerosol. The carbon preference index (CPI) of the coarse particles in August had the highest value, while in March the leaf wax contribution decreased significantly and the CPI value was very close to unity for both sites. Maximum concentrations of carbonyl compounds were reported in the range of C(15)-C(20), demonstrating that they were formed from anthropogenic activity or from atmospheric oxidative processes. 6, 10, 14-trimethylpentadecan-2-one, a marker of biogenic input, was also detected in our samples. Molecular biomarker compounds confirmed that ca. 60% of the aliphatic fraction on the sampled atmospheric particles originated from petroleum and not from any contemporary biogenic sources. Pristane and phytane were detected in the fine fraction with their presence indicating sources of fossil fuel in the range of C(16)-C(20). At all

  11. Syntheses, kinetics, and mechanism of ligand substitution reactions of 17-electron cyclopentadienyl and pentadienyl vanadium carbonyl complexes

    Energy Technology Data Exchange (ETDEWEB)

    Kowaleski, R.M.; Basolo, F.; Trogler, W.C.; Gedridge, R.W.; Newbound, T.D.; Ernst, R.D.

    1987-08-05

    Reported are the syntheses of bis(eta/sup 5/-pentadienyl)vanadium carbonyls and corresponding triethylphosphine compounds. The CO substitution lability in the complexes (eta/sup 5/-L)/sub 2/ VCO (L = C/sub 5/H/sub 5/, C/sub 5/Me/sub 5/, C/sub 5/H/sub 7/, 2,4-C/sub 7/H/sub 11/) was investigated. The exchange reaction of (eta/sup 5/-C/sub 5/H/sub 5/)/sub 2/V/sup 13/CO or of (eta/sup 5/-C/sub 5/Me/sub 5/)/sub 2/V/sup 13/CO with CO is first-order in both CO and metal complex: for L = C/sub 5/Me/sub 5/, kinetic parameters in toluene are ..delta..H/sub 2//sup double dagger/ = 8.9 +/- 0.7 kcal/mol, ..delta..S/sub 2//sup double dagger/ = -21 +/- 3 cal/(mol K), and k/sub 2/ (0.0/sup 0/C) = 12.7 (+/- 0.1) M/sup -1/s/sup -1/. The rate of CO addition to the 15-electron complex CP*/sub 2/V is slower than the CO exchange rate for Cp*/sub 2/VCO: ..delta..H/sup double dagger/ = 6.3 +/- 0.1 kcal/mol, ..delta..S/sup double dagger/ = -37 +/- 4 cal/(mol K), and k (0.0/sup 0/C, toluene) = 0.424 +/- 0.005 M/sup -1/ s/sup -1/. The vanadium carbonyl complexes containing one or two pentadienyl ligands react 10/sup 3/-10/sup 4/ times slower than the bis(cyclopentadienyl) complexes, and the CO exchange rates depend only slightly on CO concentration. The electronic and steric features in these complexes, which allow for associative reactions for (eta/sup 5/-C/sub 5/H/sub 5/)/sub 2/ VCO and (eta/sup 5/-C/sub 5/Me/sub 5/)/sub 2/ VCO but prohibit this pathway for the pentadienyl complexes, are discussed.

  12. Efficicent (R-phenylethanol production with enantioselectivity-alerted (S-carbonyl reductase II and NADPH regeneration.

    Directory of Open Access Journals (Sweden)

    Rongzhen Zhang

    Full Text Available The NADPH-dependent (S-carbonyl reductaseII from Candida parapsilosis catalyzes acetophenone to chiral phenylethanol in a very low yield of 3.2%. Site-directed mutagenesis was used to design two mutants Ala220Asp and Glu228Ser, inside or adjacent to the substrate-binding pocket. Both mutations caused a significant enantioselectivity shift toward (R-phenylethanol in the reduction of acetophenone. The variant E228S produced (R-phenylethanol with an optical purity above 99%, in 80.2% yield. The E228S mutation resulted in a 4.6-fold decrease in the K M value, but nearly 5-fold and 21-fold increases in the k cat and k cat/K M values with respect to the wild type. For NADPH regeneration, Bacillus sp. YX-1 glucose dehydrogenase was introduced into the (R-phenylethanol pathway. A coexpression system containing E228S and glucose dehydrogenase was constructed. The system was optimized by altering the coding gene order on the plasmid and using the Shine-Dalgarno sequence and the aligned spacing sequence as a linker between them. The presence of glucose dehydrogenase increased the NADPH concentration slightly and decreased NADP(+ pool 2- to 4-fold; the NADPH/NADP(+ ratio was improved 2- to 5-fold. The recombinant Escherichia coli/pET-MS-SD-AS-G, with E228S located upstream and glucose dehydrogenase downstream, showed excellent performance, giving (R-phenylethanol of an optical purity of 99.5 % in 92.2% yield in 12 h in the absence of an external cofactor. When 0.06 mM NADP(+ was added at the beginning of the reaction, the reaction duration was reduced to 1 h. Optimization of the coexpression system stimulated an over 30-fold increase in the yield of (R-phenylethanol, and simultaneously reduced the reaction time 48-fold compared with the wild-type enzyme. This report describes possible mechanisms for alteration of the enantiopreferences of carbonyl reductases by site mutation, and cofactor rebalancing pathways for efficient chiral alcohols production.

  13. Reputation in Higher Education

    DEFF Research Database (Denmark)

    Martensen, Anne; Grønholdt, Lars

    2005-01-01

    The purpose of this paper is to develop a reputation model for higher education programmes, provide empirical evidence for the model and illustrate its application by using Copenhagen Business School (CBS) as the recurrent case. The developed model is a cause-and-effect model linking image...... for higher education reputation and which relations exist between the included determinants from a theoretical perspective. It is demonstrated how the model and measurement system may be a useful management tool for the improvement of the reputation of a higher education. In this way, the model can help...... leaders of higher education institutions to set strategic directions and support their decisions in an effort to create even better study programmes with a better reputation. Finally, managerial implications and directions for future research are discussed.Keywords: Reputation, image, corporate identity...

  14. Higher Education in Scandinavia

    DEFF Research Database (Denmark)

    Nielsen, Jørgen Lerche; Birch Andreasen, Lars

    2015-01-01

    Higher education systems around the world have been undergoing fundamental changes through the last 50 years from more narrow self-sustaining universities for the elite and into mass universities, where new groups of students have been recruited and the number of students enrolled has increased....... In this chapter we will examine how higher education systems in Scandinavia are developing in relation to these challenges. To what extent has the democratic tradition had an impact on the educational systems, and what possible futures can be envisioned? In the development of higher education in Scandinavia......, there are different perspectives on education at play. One perspective sees education as a “public good” that benefits society and therefore should be free and accessible for all students who qualify to be admitted. According to this perspective, one of the main purposes of higher education is to add value to all...

  15. Higher Spins & Strings

    CERN Multimedia

    CERN. Geneva

    2014-01-01

    The conjectured relation between higher spin theories on anti de-Sitter (AdS) spaces and weakly coupled conformal field theories is reviewed. I shall then outline the evidence in favour of a concrete duality of this kind, relating a specific higher spin theory on AdS3 to a family of 2d minimal model CFTs. Finally, I shall explain how this relation fits into the framework of the familiar stringy AdS/CFT correspondence.

  16. INTERNATIONALIZATION IN HIGHER EDUCATION

    OpenAIRE

    Catalina Crisan-Mitra; Anca Borza

    2015-01-01

    Internationalization of higher education is one of the key trends of development. There are several approaches on how to achieve competitiveness and performance in higher education and international academic mobility; students’ exchange programs, partnerships are some of the aspects that can play a significant role in this process. This paper wants to point out the student’s perception regarding two main directions: one about the master students’ expectation regarding how an internationalized...

  17. Free-radical carbonylation. Efficient trapping of carbon monoxide by carbon radicals

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Ilhyong; Kusano, Kazuya; Ogawa, Akiya; Kambe, Nobuaki; Sonoda, Noboru (Osaka Univ. (Japan))

    1990-01-31

    The authors examined the AIBN-induced radical reaction of n-octyl bromide (1) (Scheme 1) with Bu{sub 3}SnH under CO pressure in hope of trapping of carbon monoxide by octyl radical followed by hydrogen abstraction from tin hydride. When the reaction on a 0.5-mmol scale was conducted under CO pressure, using an autoclave with an inserted glass tube (5 mol % of AIBN, benzene (10 mL), 80{degree}C, 3 h), the desired aldehyde 2 was obtained together with n-octane (3), formed via simple reduction of 1. Surprisingly, this radical/CO trapping sequence proceeds even at 15 atm of CO pressure to give 2 in 38% yield (run 2). Generally, higher pressures of CO resulted in the increase of 2. These results demonstrate that the control of the relative concentrations of CO to tin hydride is an important factor to effect the CO trapping leading to aldehyde 2.

  18. Experimental and Theoretical Reduction Potentials of Some Biologically Active ortho-Carbonyl para-Quinones.

    Science.gov (United States)

    Martínez-Cifuentes, Maximiliano; Salazar, Ricardo; Ramírez-Rodríguez, Oney; Weiss-López, Boris; Araya-Maturana, Ramiro

    2017-04-04

    The rational design of quinones with specific redox properties is an issue of great interest because of their applications in pharmaceutical and material sciences. In this work, the electrochemical behavior of a series of four p-quinones was studied experimentally and theoretically. The first and second one-electron reduction potentials of the quinones were determined using cyclic voltammetry and correlated with those calculated by density functional theory (DFT) using three different functionals, BHandHLYP, M06-2x and PBE0. The differences among the experimental reduction potentials were explained in terms of structural effects on the stabilities of the formed species. DFT calculations accurately reproduced the first one-electron experimental reduction potentials with R² higher than 0.94. The BHandHLYP functional presented the best fit to the experimental values (R² = 0.957), followed by M06-2x (R² = 0.947) and PBE0 (R² = 0.942).

  19. Combining image-derived and venous input functions enables quantification of serotonin-1A receptors with [carbonyl-11C]WAY-100635 independent of arterial sampling.

    Science.gov (United States)

    Hahn, Andreas; Nics, Lukas; Baldinger, Pia; Ungersböck, Johanna; Dolliner, Peter; Frey, Richard; Birkfellner, Wolfgang; Mitterhauser, Markus; Wadsak, Wolfgang; Karanikas, Georgios; Kasper, Siegfried; Lanzenberger, Rupert

    2012-08-01

    image- derived input functions (IDIFs) represent a promising technique for a simpler and less invasive quantification of PET studies as compared to arterial cannulation. However, a number of limitations complicate the routine use of IDIFs in clinical research protocols and the full substitution of manual arterial samples by venous ones has hardly been evaluated. This study aims for a direct validation of IDIFs and venous data for the quantification of serotonin-1A receptor binding (5-HT(1A)) with [carbonyl-(11)C]WAY-100635 before and after hormone treatment. Fifteen PET measurements with arterial and venous blood sampling were obtained from 10 healthy women, 8 scans before and 7 after eight weeks of hormone replacement therapy. Image-derived input functions were derived automatically from cerebral blood vessels, corrected for partial volume effects and combined with venous manual samples from 10 min onward (IDIF+VIF). Corrections for plasma/whole-blood ratio and metabolites were done separately with arterial and venous samples. 5-HT(1A) receptor quantification was achieved with arterial input functions (AIF) and IDIF+VIF using a two-tissue compartment model. Comparison between arterial and venous manual blood samples yielded excellent reproducibility. Variability (VAR) was less than 10% for whole-blood activity (p>0.4) and below 2% for plasma to whole-blood ratios (p>0.4). Variability was slightly higher for parent fractions (VARmax=24% at 5 min, p0.1) but still within previously reported values. IDIFs after partial volume correction had peak values comparable to AIFs (mean difference Δ=-7.6 ± 16.9 kBq/ml, p>0.1), whereas AIFs exhibited a delay (Δ=4 ± 6.4s, pderived and venous input functions provides a reliable quantification of 5-HT(1A) receptors. This holds true for 5-HT(1A) binding estimates before and after treatment for both regions of interest-based and voxel-wise modeling. Taken together, the approach provides less invasive receptor quantification by

  20. Fuel Class Higher Alcohols

    KAUST Repository

    Sarathy, Mani

    2016-08-17

    This chapter focuses on the production and combustion of alcohol fuels with four or more carbon atoms, which we classify as higher alcohols. It assesses the feasibility of utilizing various C4-C8 alcohols as fuels for internal combustion engines. Utilizing higher-molecular-weight alcohols as fuels requires careful analysis of their fuel properties. ASTM standards provide fuel property requirements for spark-ignition (SI) and compression-ignition (CI) engines such as the stability, lubricity, viscosity, and cold filter plugging point (CFPP) properties of blends of higher alcohols. Important combustion properties that are studied include laminar and turbulent flame speeds, flame blowout/extinction limits, ignition delay under various mixing conditions, and gas-phase and particulate emissions. The chapter focuses on the combustion of higher alcohols in reciprocating SI and CI engines and discusses higher alcohol performance in SI and CI engines. Finally, the chapter identifies the sources, production pathways, and technologies currently being pursued for production of some fuels, including n-butanol, iso-butanol, and n-octanol.

  1. [Association between carbonyl proteins and tumor necrosis factor alpha with muscle strength in young and older women: exploratory study].

    Science.gov (United States)

    Martínez Huenchullán, Sergio Francisco; Mancilla Solorza, Eladio Bernabé

    2015-01-01

    It has recently been proposed that there is a close relationship between oxidative stress and low-grade chronic inflammation. Both processes have been related separately to muscle function in older adults (OA). Nevertheless, it still has not been determined if this relationship is present particularly in OA. The objective of this study was to determine the relationship between the plasma levels of TNF-α and carbonyl proteins (CP) and muscle strength in a group of young and older women. An exploratory study was conducted on 13 older and 8 young women, in whom the plasma levels of CP and TNF-α were measured. Muscle strength was measured by handgrip test, quadriceps voluntary maximal isometric strength, arm curl, and the 30 second sit to stand test. There were no differences in the plasma levels of CP and TNF-α between the groups, but there was relationship between the biomarkers only in the OA group. A non-linear relationship was observed between CP and quadriceps voluntary maximal isometric strength only in the OA group (R(2)=36.2; P=.038). For TNF-α there were no significant association with any of the applied tests. There is an association between CP and quadriceps voluntary maximal isometric strength only in the OA group, which could indicate a deleterious action of oxidative stress on muscle function, particularly in aging. Copyright © 2015 SEGG. Published by Elsevier Espana. All rights reserved.

  2. The Calvin cycle inevitably produces sugar-derived reactive carbonyl methylglyoxal during photosynthesis: a potential cause of plant diabetes.

    Science.gov (United States)

    Takagi, Daisuke; Inoue, Hironori; Odawara, Mizue; Shimakawa, Ginga; Miyake, Chikahiro

    2014-02-01

    Sugar-derived reactive carbonyls (RCs), including methylglyoxal (MG), are aggressive by-products of oxidative stress known to impair the functions of multiple proteins. These advanced glycation end-products accumulate in patients with diabetes mellitus and cause major complications, including arteriosclerosis and cardiac insufficiency. In the glycolytic pathway, the equilibration reactions between dihydroxyacetone phosphate and glyceraldehyde 3-phosphate (GAP) have recently been shown to generate MG as a by-product. Because plants produce vast amounts of sugars and support the same reaction in the Calvin cycle, we hypothesized that MG also accumulates in chloroplasts. Incubating isolated chloroplasts with excess 3-phosphoglycerate (3-PGA) as the GAP precursor drove the equilibration reaction toward MG production. The rate of oxygen (O2) evolution was used as an index of 3-PGA-mediated photosynthesis. The 3-PGA- and time-dependent accumulation of MG in chloroplasts was confirmed by HPLC. In addition, MG production increased with an increase in light intensity. We also observed a positive linear relationship between the rates of MG production and O2 evolution (R = 0.88; P photosynthesis. Furthermore, we found that MG production is enhanced under high-CO2 conditions in illuminated wheat leaves.

  3. Protein carbonyl: An oxidative stress marker in gingival crevicular fluid in healthy, gingivitis, and chronic periodontitis subjects

    Directory of Open Access Journals (Sweden)

    Avani R Pradeep

    2013-01-01

    Full Text Available Background: A defined role for reactive oxygen species (ROS in the tissue destruction that characterizes periodontitis has been described. Protein carbonyl (PC is the most widely used biomarker for oxidative damage to proteins, and reflects cellular damage induced by multiple forms of ROS. The purpose of this study is to determine the presence of PC in gingival crevicular fluid (GCF in healthy, gingivitis, and chronic periodontitis (CP subjects and to find an association, if any. Materials and Methods: A total number of 75 subjects (38 males and 37 females were selected based on their clinical parameters into three groups: Group 1 (25 healthy subjects, Group 2 (25 gingivitis subjects, and Group 3 (25 CP subjects. GCF samples were collected to estimate the levels of PC. Results: The PC concentration in GCF was highest in subjects with CP as compared to gingivitis and healthy subjects and a significant association was observed between GCF PC levels and all periodontal parameters. Conclusion: There was an increase in PC levels in GCF as the disease process progressed from healthy to gingivitis and CP, suggesting a role for increased oxidative stress in CP.

  4. Characteristics of odorous carbonyl compounds in the ambient air around a fishery industrial complex of Yeosu, Korea.

    Science.gov (United States)

    Ma, Zhongkun; Jeon, Junmin; Kim, Sangchai; Jung, Sangchul; Lee, Woobum; Seo, Seonggyu

    2012-01-01

    In this study, the amounts of odorous carbonyl compounds (OCCs) including acetaldehyde (Acet-A), propionaldehyde (Pron-A), butylaldehyde (Buty-A), iso-valeric aldehyde (Iso-Vale-A) and n-valeric aldehyde (N-Vale-A) emitted from a fishery industrial complex near the exhibition facilities of "Expo 2012 Yeosu Korea" were measured. Acet-A was found to be the most abundant OCC, and the total concentrations of the OCCs were the highest in the summer. However, due to vehicular exhaust and photochemical reactions, the concentrations of some of the OCCs presented their highest levels in the fall. A significant correlation between Acet-A and Buty-A was found at the major fishery facilities (r = 0.816, p = 1.87E-15, n = 60) and at the border areas (r = 0.809, p = 3.40E-12, n = 48) of this fishery industrial complex. The concentrations of OCCs at the border areas were not worse than those at the urban areas in other places, indicating that the concentrations of ambient OCCs at the border areas were not greatly influenced by manmade activities.

  5. Influence of Elevated CO2 on the Carbonyl Sulfide (OCS, COS) Exchange between Plants, Soils and the Atmosphere

    Science.gov (United States)

    Bunk, R.; Behrendt, T.; Yi, Z.; Andreae, M. O.; Kesselmeier, J.

    2016-12-01

    Carbonyl sulfide (OCS) is a sulfur-containing trace gas with an atmospheric concentration of about 500 ppt. As it has some impact on the tropospheric greenhouse effect as well as on the stratospheric cooling effect by aerosols, its biogeochemical cycling if of high interest. Furthermore, in view of the close similarities between the assimilation of CO2 and OCS, terrestrial vegetation is regarded as the main global sink for OCS. Within this context, there is an increasing interest to use OCS as a proxy for CO2 to study ecosystem or global CO2 fluxes, exploiting the parallels between CO2 and OCS uptake by plants. However, the exchange of OCS between an ecosystem and the atmosphere does not only depend on vegetation but also on soils. We investigated the exchange processes between soils and the atmosphere and report on the impact of high but realistic CO2 concentrations on soil/atmosphere exchange and its relation to the soil water content. Not only competitive inhibition (same enzymes for CO2 and OCS uptake) but an influence on OCS production could be found. We compare these environmental effects on soils with the exchange processes between plants and the atmosphere demonstrating similar effects reaching from competitive inhibition to production of OCS.

  6. Multiple magnetic resonance and microwave absorption of metamaterial absorbers composed of double split ring resonators on grounded carbonyl iron composites

    Science.gov (United States)

    Lim, Jun-Hee; Kim, Sung-Soo

    2017-12-01

    This study investigates the triple-band absorption properties of metamaterial absorbers composed of a double split ring resonator (DSRR) on a grounded magnetic substrate of carbonyl iron powders. Computational tools are used to model the interaction between electromagnetic waves and the metamaterial structure. For perpendicular polarization with the electric field perpendicular to the SRR gap, triple-band absorption peaks are predicted in the simulation result of reflection loss. Magnetic resonance resulting from antiparallel currents between the upper DSRR and the lower ground plane is identified at the frequencies of the absorption peaks. The orientation of the two resonators influences the absorption characteristics, especially in the second and third peaks where the coupling between the inner SRR and outer SRR is strong. The current density distribution indicates that the two resonators oriented in the same direction achieve reduced coupling between them, which results in two absorption frequencies close to each other. For parallel polarization with the electric field parallel to the SRR gap, this study predicts dual-band absorption peaks corresponding to the magnetic resonance at the SRR wire.

  7. Derivatization and detection of small aliphatic and lipid-bound carbonylated lipid peroxidation products by ESI-MS.

    Science.gov (United States)

    Milic, Ivana; Fedorova, Maria

    2015-01-01

    Double bonds in polyunsaturated fatty acids (PUFA) and lipids are one of the major targets of reactive oxygen species (ROS). The resulting lipid peroxidation products (LPP) represent a group of chemically diverse compounds formed by several consecutive oxidative reactions. Oxidative cleavage leads to the formation of small aliphatic and lipid-bound aldehydes and ketones (oxoLPPs). These strong electrophiles can readily react with nucleophilic substrates, for example, side chains in proteins which can alter structure, function, and cellular distribution of the modified proteins. Despite growing interest in the field of oxidative lipidomics, only a few dominantly formed oxoLPP were identified. Due to the chemical and physical properties, aliphatic oxoLPPs are usually analyzed using gas chromatography-mass spectrometry (GC- MS), while nonvolatile lipid-bound oxoLPPs require liquid chromatography-mass spectrometry (LC-MS). To overcome the need for the two analyses, we have developed a new derivatization strategy to capture all oxoLPP independent to their properties with electrospray ionization (ESI) MS allowing simultaneous detection of aliphatic and lipid-bound oxoLPPs. Thus, the 7-(diethylamino)coumarin-3-carbohydrazide (CHH) derivatization reagent allowed us to identify 122 carbonyl compounds in a mixture of four PUFA and phosphatidylcholines (PC) oxidized in vitro.

  8. Electromagnetic, magnetorheological and stability properties of polysiloxane elastomers based on silane-modified carbonyl iron particles with enhanced wettability

    Science.gov (United States)

    Cvek, Martin; Moucka, Robert; Sedlacik, Michal; Pavlinek, Vladimir

    2017-10-01

    Soft carbonyl iron (CI) particles were successfully modified with a thin layer of tetraethoxysilane (TEOS) to enhance the wettability of their surface in hydrophobic media. The contact angle investigations and tensiometric analysis revealed and helped quantify the significantly enhanced wettability and, thus, the better interfacial adhesion of the TEOS-coated CI particles (CI-TEOS) with the non-polar siloxane-based materials. Therefore, stable magnetorheological elastomers (MREs) based on CI-TEOS particles and polydimethyl siloxane matrix were fabricated. The prepared composites had different particle loadings and microstructural characteristics: isotropic and anisotropic. These structural differences were confirmed by scanning electron microscopy and were found to considerably affect dielectric properties of the MREs due to various charge transport mechanisms within the particle clusters. Furthermore, the magnetorheological (MR) performances of isotropic MRE variants were analysed before and after exposure to acidic environment. After the corrosion test, the MRE based on bare CI particles exhibited dramatically decreased relative MR effect and mechanical properties when compared with its analogue containing CI-TEOS.

  9. Structure and characterization of a NAD(P)H-dependent carbonyl reductase from Pseudomonas aeruginosa PAO1.

    Science.gov (United States)

    Li, Shanshan; Teng, Xiaozhen; Su, Li; Mao, Guannan; Xu, Yueyang; Li, Tingting; Liu, Riuhua; Zhang, Qionglin; Wang, Yingying; Bartlam, Mark

    2017-06-01

    To investigate the function of the pa4079 gene from the opportunistic pathogen Pseudomonas aeruginosa PAO1, we determined its crystal structure and confirmed it to be a NAD(P)-dependent short-chain dehydrogenase/reductase. Structural similarity and activity for a broad range of substrates indicate that PA4079 functions as a carbonyl reductase. Comparison of apo- and holo-PA4079 shows that NADP stabilizes the active site specificity loop, and small molecule binding induces rotation of the Tyr183 side chain by approximately 90° out of the active site. Quantitative real-time PCR results show that pa4079 maintains high expression levels during antibiotic exposure. This work provides a starting point for understanding substrate recognition and selectivity by PA4079, as well as its possible reduction of antimicrobial drugs. Structural data are available in the Protein Data Bank (PDB) under the following accession numbers: apo PA4079 (condition I), 5WQM; apo PA4079 (condition II), 5WQN; PA4079 + NADP (condition I), 5WQO; PA4079 + NADP (condition II), 5WQP. © 2017 Federation of European Biochemical Societies.

  10. In-situ formation, thermal decomposition, and adsorption studies of transition metal carbonyl complexes with short-lived radioisotopes

    Energy Technology Data Exchange (ETDEWEB)

    Even, Julia [Helmholtz-Institut Mainz (Germany); Mainz Univ. (Germany); Duellmann, Emanuel [Mainz Univ. (Germany); Helmholtz-Institut Mainz (Germany); GSI Helmholzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); Yakushev, Alexander [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); and others

    2014-07-01

    We report on the in-situ synthesis of metal carbonyl complexes with short-lived isotopes of transition metals. Complexes of molybdenum, technetium, ruthenium and rhodium were synthesized by thermalisation of products of neutron-induced fission of {sup 249}Cf in a carbon monoxide-nitrogen mixture. Complexes of tungsten, rhenium, osmium, and iridium were synthesized by thermalizing short-lived isotopes produced in {sup 24}Mg-induced fusion evaporation reactions in a carbon monoxide containing atmosphere. The chemical reactions took place at ambient temperature and pressure conditions. The complexes were rapidly transported in a gas stream to collection setups or gas phase chromatography devices. The physisorption of the complexes on Au and SiO{sub 2} surfaces was studied. We also studied the stability of some of the complexes, showing that these start to decompose at temperatures above 300 C in contact with a quartz surface. Our studies lay a basis for the investigation of such complexes with transactinides.

  11. Identification of the urinary metabolites of 4-bromoaniline and 4-bromo-[carbonyl-13C]-acetanilide in rat.

    Science.gov (United States)

    Scarfe, G B; Nicholson, J K; Lindon, J C; Wilson, I D; Taylor, S; Clayton, E; Wright, B

    2002-04-01

    1. The urinary excretion of 4-bromoaniline and its [carbonyl-(13)C]-labelled N-acetanilide, together with their corresponding metabolites, have been investigated in the rat following i.p. administration at 50 mg kg(-1). 2. Metabolite profiling was performed by reversed-phase HPLC with UV detection, whilst identification was performed using a combination of enzymic hydrolysis and directly coupled HPLC-NMR-MS analysis. The urinary metabolite profile was quantitatively and qualitatively similar for both compounds with little of either excreted unchanged. 3. The major metabolite present in urine was 2-amino-5-bromophenylsulphate, but, in addition, a number of metabolites with modification of the N-acetyl moiety were identified (from both the [(13)C]-acetanilide or produced following acetylation of the free bromoaniline). 4. For 4-bromoacetanilide, N-deacetylation was a major route of metabolism, but despite the detection of the acetanilide following the administration of the free aniline, there was no evidence of reacetylation (futile deacetylation). 5. Metabolites resulting from the oxidation of the acetyl group included a novel glucuronide of an N-glycolanilide, an unusual N-oxanilic acid and a novel N-acetyl cysteine conjugate.

  12. Synthesis and Antimicrobial Activity of N-(6-Carboxyl Cyclohex-3-ene Carbonyl Chitosan with Different Degrees of Substitution

    Directory of Open Access Journals (Sweden)

    Mohamed E. I. Badawy

    2016-01-01

    Full Text Available Five products of N-(6-carboxyl cyclohex-3-ene carbonyl chitosan as antimicrobial agents were prepared by reaction of chitosan with tetrahydrophthalic anhydride (THPA at different degrees of substitution (DS. The antimicrobial activity was evaluated against four plant bacteria and eight fungi. The results proved that the inhibitory property and water solubility of the synthesized chitosan derivatives, with increase of the DS, exhibited a remarkable improvement over chitosan. The product with a DS of 0.40 was the most active one with MIC of 510, 735, 240, and 385 mg/L against Erwinia carotovora, Ralstonia solanacearum, Rhodococcus fascians, and Rhizobium radiobacter, respectively, and also in mycelial growth inhibition against Alternaria alternata (EC50 = 683 mg/L, Botrytis cinerea (EC50 = 774 mg/L, Botryodiplodia theobromae (EC50 = 501 mg/L, Fusarium oxysporum (EC50 = 500 mg/L, F. solani (EC50 = 260 mg/L, Penicillium digitatum (EC50 = 417 mg/L, Phytophthora infestans (EC50 = 298 mg/L, and Sclerotinia sclerotiorum (EC50 = 763 mg/L. These compounds based on a biodegradable and biocompatible chitosan could be used as potentially antimicrobial agents in crop protection instead of hazardous synthetic pesticides.

  13. A rhenium tris-carbonyl derivative as a model molecule for incorporation into phospholipid assemblies for skin applications.

    Science.gov (United States)

    Fernández, Estibalitz; Rodríguez, Gelen; Hostachy, Sarah; Clède, Sylvain; Cócera, Mercedes; Sandt, Christophe; Lambert, François; de la Maza, Alfonso; Policar, Clotilde; López, Olga

    2015-07-01

    A rhenium tris-carbonyl derivative (fac-[Re(CO)3Cl(2-(1-dodecyl-1H-1,2,3,triazol-4-yl)-pyridine)]) was incorporated into phospholipid assemblies, called bicosomes, and the penetration of this molecule into skin was monitored using Fourier-transform infrared microspectroscopy (FTIR). To evaluate the capacity of bicosomes to promote the penetration of this derivative, the skin penetration of the Re(CO)3 derivative dissolved in dimethyl sulfoxide (DMSO), a typical enhancer, was also studied. Dynamic light scattering results (DLS) showed an increase in the size of the bicosomes with the incorporation of the Re(CO)3 derivative, and the FTIR microspectroscopy showed that the Re(CO)3 derivative incorporated in bicosomes penetrated deeper into the skin than when dissolved in DMSO. When this molecule was applied on the skin using the bicosomes, 60% of the Re(CO)3 derivative was retained in the stratum corneum (SC) and 40% reached the epidermis (Epi). Otherwise, the application of this molecule via DMSO resulted in 95% of the Re(CO)3 derivative being in the SC and only 5% reaching the Epi. Using a Re(CO)3 derivative with a dodecyl-chain as a model molecule, it was possible to determine the distribution of molecules with similar physicochemical characteristics in the skin using bicosomes. This fact makes these nanostructures promising vehicles for the application of lipophilic molecules inside the skin. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Protein Carbonyl as a Biomarker of Oxidative Stress in Severe Leptospirosis, and Its Usefulness in Differentiating Leptospirosis from Dengue Infections.

    Science.gov (United States)

    Fernando, Narmada; Wickremesinghe, Shalini; Niloofa, Roshan; Rodrigo, Chaturaka; Karunanayake, Lilani; de Silva, H Janaka; Wickremesinghe, A R; Premawansa, Sunil; Rajapakse, Senaka; Handunnetti, Shiroma M

    2016-01-01

    Pathogenesis of disease severity in leptospirosis is not clearly understood whether it is due to direct damage by pathogen or by adverse immune responses. Knowledge on biomarkers of oxidative stress which could be used in identifying patients with severe illness has shown to be of great value in disease management. Thus, the main aim of this study was to assess the damage to serum proteins and lipids, and their significance as biomarkers of oxidative stress in severe leptospirosis. In regions endemic for both leptospirosis and dengue, leptospirosis cases are often misdiagnosed as dengue during dengue epidemics. Therefore, the second aim was to assess the potential of the oxidative stress markers in differentiating severe leptospirosis from critical phase dengue. We measured serum antioxidants (uric acid and bilirubin), total antioxidant capacity (AOC), protein carbonyl (PC) and lipid hydroperoxide (LP) in patients with severe leptospirosis (n = 60), mild leptospirosis (n = 50), dengue during the critical phase (n = 30) and in healthy subjects (n = 30). All patient groups had similar total antioxidant capacity levels. However, the presence of significantly high uric acid and total bilirubin levels may reflect the degree of renal and hepatic involvement seen in severe leptospirosis patients (pleptospirosis patients compared to critical phase dengue infections (pleptospirosis patients (AUC = 0.99) and also to differentiate severe leptospirosis from mild cases (AUC = 0.78; pleptospirosis severity and as an oxidative stress biomarker in differentiating leptospirosis from dengue would provide the opportunity to save lives via prompt patient management.

  15. Quality of Higher Education

    DEFF Research Database (Denmark)

    Zou, Yihuan; Zhao, Yingsheng; Du, Xiangyun

    . This transformation involves a broad scale of change at individual level, organizational level, and societal level. In this change process in higher education, staff development remains one of the key elements for university innovation and at the same time demands a systematic and holistic approach.......This paper starts with a critical approach to reflect on the current practice of quality assessment and assurance in higher education. This is followed by a proposal that in response to the global challenges for improving the quality of higher education, universities should take active actions...... of change by improving the quality of teaching and learning. From a constructivist perspective of understanding education and learning, this paper also discusses why and how universities should give more weight to learning and change the traditional role of teaching to an innovative approach of facilitation...

  16. INTERNATIONALIZATION IN HIGHER EDUCATION

    Directory of Open Access Journals (Sweden)

    Catalina Crisan-Mitra

    2016-03-01

    Full Text Available Internationalization of higher education is one of the key trends of development. There are several approaches on how to achieve competitiveness and performance in higher education and international academic mobility; students’ exchange programs, partnerships are some of the aspects that can play a significant role in this process. This paper wants to point out the student’s perception regarding two main directions: one about the master students’ expectation regarding how an internationalized master should be organized and should function, and second the degree of satisfaction of the beneficiaries of internationalized master programs from Babe-Bolyai University. This article is based on an empirical qualitative research that was implemented to students of an internationalized master from the Faculty of Economics and Business Administration. This research can be considered a useful example for those preoccupied to increase the quality of higher education and conclusions drawn have relevance both theoretically and especially practically.

  17. Higher spin gauge theories

    CERN Document Server

    Henneaux, Marc; Vasiliev, Mikhail A

    2017-01-01

    Symmetries play a fundamental role in physics. Non-Abelian gauge symmetries are the symmetries behind theories for massless spin-1 particles, while the reparametrization symmetry is behind Einstein's gravity theory for massless spin-2 particles. In supersymmetric theories these particles can be connected also to massless fermionic particles. Does Nature stop at spin-2 or can there also be massless higher spin theories. In the past strong indications have been given that such theories do not exist. However, in recent times ways to evade those constraints have been found and higher spin gauge theories have been constructed. With the advent of the AdS/CFT duality correspondence even stronger indications have been given that higher spin gauge theories play an important role in fundamental physics. All these issues were discussed at an international workshop in Singapore in November 2015 where the leading scientists in the field participated. This volume presents an up-to-date, detailed overview of the theories i...

  18. Tracking reactive intermediates by FTIR monitoring of reactions in low-temperature sublimed solids: nitric oxide disproportionation mediated by ruthenium(II) carbonyl porphyrin Ru(TPP)(CO).

    Science.gov (United States)

    Azizyan, Arsen S; Kurtikyan, Tigran S; Martirosyan, Garik G; Ford, Peter C

    2013-05-06

    Interaction of NO ((15)NO) with amorphous layers of Ru(II) carbonyl porphyrin (Ru(TPP)(CO), TPP(2-) = meso-tetraphenylporphyrinato dianion) was monitored by FTIR spectroscopy from 80 K to room temperature. An intermediate spectrally characterized at very low temperatures (110 K) with ν(CO) at 2001 cm(-1) and ν(NO) at 1810 cm(-1) (1777 cm(-1) for (15)NO isotopomer) was readily assigned to the mixed carbonyl-nitrosyl complex Ru(TPP)(CO)(NO), which is the logical precursor to CO labilization. Remarkably, Ru(TPP)-mediated disproportionation of NO is seen even at 110 K, an indication of how facile this reaction is. By varying the quantity of supplied NO, it was also demonstrated that the key intermediate responsible for NO disproportionation is the dinitrosyl complex Ru(TPP)(NO)2, supporting the conclusion previously made from solution experiments.

  19. Effects of organic contaminants in reactive oxygen species, protein carbonylation and DNA damage on digestive gland and haemolymph of land snails.

    Science.gov (United States)

    Itziou, A; Kaloyianni, M; Dimitriadis, V K

    2011-10-01

    The present study focused on early responses of land snails Eobania vermiculata to organic environmental contaminants, by investigating the use of a newly-established method for the measurement of protein carbonylation as a new biomarker of terrestrial pollution, as well as by measuring the ROS production and the DNA damage. Land snails were exposed to different concentrations of chlorpyrifos, parathion-methyl or PAHs in vivo or in vitro in the laboratory. The susceptibility of exposed snails was increased in relation to oxidative stress induced by contaminants tested. A statistically significant increase in ROS production, protein carbonylation and DNA damage was revealed in the snails treated with pollutants, compared to the untreated ones. The results indicated the effectiveness of measuring ROS production and DNA damage and reinforce the application of the present ELISA method in organic terrestrial pollution biomonitoring studies. Copyright © 2011 Elsevier Ltd. All rights reserved.

  20. Reductive Umpolung of Carbonyl Derivatives with Visible-Light Photoredox Catalysis: Direct Access to Vicinal Diamines and Amino Alcohols via α-Amino Radicals and Ketyl Radicals

    KAUST Repository

    Fava, Eleonora

    2016-05-02

    Visible-light-mediated photoredox-catalyzed aldimine-aniline and aldehyde-aniline couplings have been realized. The reductive single electron transfer (SET) umpolung of various carbonyl derivatives enabled the generation of intermediary ketyl and α-amino radical anions, which were utilized for the synthesis of unsymmetrically substituted 1,2-diamines and amino alcohols. Anilines can be coupled with aldimines or aldehydes in a visible-light-mediated photoredox-catalyzed process. Reductive single electron transfer (SET) umpolung of the carbonyl derivatives leads to the generation of intermediary ketyl and α-amino radical anions, which were used for the synthesis of unsymmetrically substituted 1,2-diamines and amino alcohols.

  1. Spectroscopic determination of hydrogenation rates and intermediates during carbonyl hydrogenation catalyzed by Shvo's hydroxycyclopentadienyl diruthenium hydride agrees with kinetic modeling based on independently measured rates of elementary reactions.

    Science.gov (United States)

    Casey, Charles P; Beetner, Sharon E; Johnson, Jeffrey B

    2008-02-20

    The catalytic hydrogenation of benzaldehyde and acetophenone with the Shvo hydrogenation catalysts were monitored by in situ IR spectroscopy in both toluene and THF. The disappearance of organic carbonyl compound and the concentrations of the ruthenium species present throughout the hydrogenation reaction were observed. The dependence of the hydrogenation rate on substrate, H2 pressure, total ruthenium concentration, and solvent were measured. In toluene, bridging diruthenium hydride 1 was the only observable ruthenium species until nearly all of the substrate was consumed. In THF, both 1 and some monoruthenium hydride 2 were observed during the course of the hydrogenation. A full kinetic model of the hydrogenation based on rate constants for individual steps in the catalysis was developed. This kinetic model simulates the rate of carbonyl compound hydrogenation and of the amounts of ruthenium species 1 and 2 present during hydrogenations.

  2. Visible-light-induced, Ir-catalyzed reactions of N-methyl-N-((trimethylsilylmethylaniline with cyclic α,β-unsaturated carbonyl compounds

    Directory of Open Access Journals (Sweden)

    Dominik Lenhart

    2014-04-01

    Full Text Available N-Methyl-N-((trimethylsilylmethylaniline was employed as reagent in visible-light-induced, iridium-catalyzed addition reactions to cyclic α,β-unsaturated carbonyl compounds. Typical reaction conditions included the use of one equivalent of the reaction substrate, 1.5 equivalents of the aniline and 2.5 mol % (in MeOH or 1.0 mol % (in CH2Cl2 [Ir(ppy2(dtbbpy]BF4 as the catalyst. Two major reaction products were obtained in combined yields of 30–67%. One product resulted from aminomethyl radical addition, the other product was a tricyclic compound, which is likely formed by attack of the intermediately formed α-carbonyl radical at the phenyl ring. For five-membered α,β-unsaturated lactone and lactam substrates, the latter products were the only products isolated. For the six-membered lactones and lactams and for cyclopentenone the simple addition products prevailed.

  3. Transition Metal-Catalyzed Carbonylative C-H Bond Functionalization of Arenes and C(sp(3))-H Bond of Alkanes.

    Science.gov (United States)

    Gadge, Sandip T; Gautam, Prashant; Bhanage, Bhalchandra M

    2016-04-01

    In this article, we present the progress made in the area of carbonylative C-H functionalization, with special emphasis on arenes and alkanes. The importance of directing group assistance and C-H functionalization using CO surrogates is also included. The budding development in the area of transition metal-catalyzed C(sp(3))-H activation makes us feel it necessary to file a summary on the past, as well as current, contributions and a prospective outlook on the transition metal-catalyzed carbonylative transformation of C-H bonds, which is the focus of this review. © 2016 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Transition metal-free oxidation of benzylic alcohols to carbonyl compounds by hydrogen peroxide in the presence of acidic silica gel

    Directory of Open Access Journals (Sweden)

    Hossein Ghafuri

    2015-01-01

    Full Text Available Oxidation of alcohols to carbonyl compounds has become an important issue in the process industry as well as many other applications. In this method, various benzylic alcohols were successfully converted to corresponding aldehydes and ketones under transition metal-free condition using hydrogen peroxide in the presence of some amount of catalytic acidic silica gel. Silica gel is inexpensive and available. One of the most important features of this method is its short reaction time.

  5. Regio- and chemoselective reduction of nitroarenes and carbonyl compounds over recyclable magnetic ferrite-nickel nanoparticles (Fe(3)O(4)-Ni) by using glycerol as a hydrogen source.

    Science.gov (United States)

    Gawande, Manoj B; Rathi, Anuj K; Branco, Paula S; Nogueira, Isabel D; Velhinho, Alexandre; Shrikhande, Janhavi J; Indulkar, Utkarsha U; Jayaram, Radha V; Ghumman, C Amjad A; Bundaleski, Nenad; Teodoro, Orlando M N D

    2012-10-01

    Reduction by magnetic nano-Fe(3)O(4)-Ni: a facile, simple and environmentally friendly hydrogen-transfer reaction that takes place over recyclable ferrite-nickel magnetic nanoparticles (Fe(3)O(4)-Ni) by using glycerol as hydrogen source allows aromatic amines and alcohols to be synthesized from the precursor nitroarenes and carbonyl compounds. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. CuI Mediated One-Pot Cycloacetalization/Ketalization of o-Carbonyl Allylbenzenes: Synthesis of Benzobicyclo[3.2.1]octane Core.

    Science.gov (United States)

    Chan, Chieh-Kai; Tsai, Yu-Lin; Chang, Meng-Yang

    2017-04-07

    CuI/DMSO-mediated intramolecular cycloacetalization/ketalization of o-carbonyl allylbenzenes has been achieved for constructing [6,6,5]-tricycles having a ketal motif in good yields. The expeditious one-step route provides a three C-O bond formation. The key products with the structural framework of a benzofused dioxabicyclo[3.2.1]octane core have been confirmed by X-ray crystallographic analysis. Synthesis of dihydroisocoumarin has been studied.

  7. Emissions of Glyoxal and Other Carbonyl Compounds from Agricultural Biomass Burning Plumes Sampled by Aircraft.

    Science.gov (United States)

    Zarzana, Kyle J; Min, Kyung-Eun; Washenfelder, Rebecca A; Kaiser, Jennifer; Krawiec-Thayer, Mitchell; Peischl, Jeff; Neuman, J Andrew; Nowak, John B; Wagner, Nicholas L; Dubè, William P; St Clair, Jason M; Wolfe, Glenn M; Hanisco, Thomas F; Keutsch, Frank N; Ryerson, Thomas B; Brown, Steven S

    2017-10-17

    We report enhancements of glyoxal and methylglyoxal relative to carbon monoxide and formaldehyde in agricultural biomass burning plumes intercepted by the NOAA WP-3D aircraft during the 2013 Southeast Nexus and 2015 Shale Oil and Natural Gas Nexus campaigns. Glyoxal and methylglyoxal were measured using broadband cavity enhanced spectroscopy, which for glyoxal provides a highly selective and sensitive measurement. While enhancement ratios of other species such as methane and formaldehyde were consistent with previous measurements, glyoxal enhancements relative to carbon monoxide averaged 0.0016 ± 0.0009, a factor of 4 lower than values used in global models. Glyoxal enhancements relative to formaldehyde were 30 times lower than previously reported, averaging 0.038 ± 0.02. Several glyoxal loss processes such as photolysis, reactions with hydroxyl radicals, and aerosol uptake were found to be insufficient to explain the lower measured values of glyoxal relative to other biomass burning trace gases, indicating that glyoxal emissions from agricultural biomass burning may be significantly overestimated. Methylglyoxal enhancements were three to six times higher than reported in other recent studies, but spectral interferences from other substituted dicarbyonyls introduce an estimated correction factor of 2 and at least a 25% uncertainty, such that accurate measurements of the enhancements are difficult.

  8. Entrepreneurship and Higher Education

    Science.gov (United States)

    Potter, Jonathan, Ed.

    2008-01-01

    Stimulating innovative and growth-oriented entrepreneurship is a key economic and societal challenge to which universities and colleges have much to contribute. This book examines the role that higher education institutions are currently playing through teaching entrepreneurship and transferring knowledge and innovation to enterprises and…

  9. Liberty and Higher Education.

    Science.gov (United States)

    Thompson, Dennis F.

    1989-01-01

    John Stuart Mill's principle of liberty is discussed with the view that it needs to be revised to guide moral judgments in higher education. Three key elements need to be modified: the action that is constrained; the constraint on the action; and the agent whose action is constrained. (MLW)

  10. Navigating in higher education

    DEFF Research Database (Denmark)

    Thingholm, Hanne Balsby; Reimer, David; Keiding, Tina Bering

    Denne rapport er skrevet på baggrund af spørgeskemaundersøgelsen – Navigating in Higher Education (NiHE) – der rummer besvarelser fra 1410 bachelorstuderende og 283 undervisere fordelt på ni uddannelser fra Aarhus Universitet: Uddannelsesvidenskab, Historie, Nordisk sprog og litteratur...

  11. California's Future: Higher Education

    Science.gov (United States)

    Johnson, Hans

    2015-01-01

    California's higher education system is not keeping up with the changing economy. Projections suggest that the state's economy will continue to need more highly educated workers. In 2025, if current trends persist, 41 percent of jobs will require at least a bachelor's degree and 36 percent will require some college education short of a bachelor's…

  12. Higher-level Innovization

    DEFF Research Database (Denmark)

    Bandaru, Sunith; Tutum, Cem Celal; Deb, Kalyanmoy

    2011-01-01

    we introduce the higher-level innovization task through an application of a manufacturing process simulation for the Friction Stir Welding (FSW) process where commonalities among two different Pareto-optimal fronts are analyzed. Multiple design rules are simultaneously deciphered from each front...

  13. Cyberbullying in Higher Education

    Science.gov (United States)

    Minor, Maria A.; Smith, Gina S.; Brashen, Henry

    2013-01-01

    Bullying has extended beyond the schoolyard into online forums in the form of cyberbullying. Cyberbullying is a growing concern due to the effect on its victims. Current studies focus on grades K-12; however, cyberbullying has entered the world of higher education. The focus of this study was to identify the existence of cyberbullying in higher…

  14. Creativity in Higher Education

    Science.gov (United States)

    Gaspar, Drazena; Mabic, Mirela

    2015-01-01

    The paper presents results of research related to perception of creativity in higher education made by the authors at the University of Mostar from Bosnia and Herzegovina. This research was based on a survey conducted among teachers and students at the University. The authors developed two types of questionnaires, one for teachers and the other…

  15. Evaluation in Higher Education

    Science.gov (United States)

    Bognar, Branko; Bungic, Maja

    2014-01-01

    One of the means of transforming classroom experience is by conducting action research with students. This paper reports about the action research with university students. It has been carried out within a semester of the course "Methods of Upbringing". Its goal has been to improve evaluation of higher education teaching. Different forms…

  16. Pedagogy in Higher Education

    Directory of Open Access Journals (Sweden)

    Jorge Luis Dahik Cabrera

    2016-06-01

    Full Text Available This review determines the factors that should involve the current education from a university pedagogy that addresses sociological, psychological, axiological, cultural and economic conditions; also highlighting the skills to be addressed by the teacher in the knowledge society and the relevant number of functions that higher education institutions should be attributed it.

  17. Pedagogy in Higher Education

    OpenAIRE

    Jorge Luis Dahik Cabrera

    2016-01-01

    This review determines the factors that should involve the current education from a university pedagogy that addresses sociological, psychological, axiological, cultural and economic conditions; also highlighting the skills to be addressed by the teacher in the knowledge society and the relevant number of functions that higher education institutions should be attributed it.

  18. Leadership in Higher Education.

    Science.gov (United States)

    Robles, Harriett J.

    This paper examines leadership in higher education, specifically in community colleges. The first section reviews current definitions and theories of education, including transactional leadership (where there is an exchange between the leader and the follower) and transformational leadership (where the leader tries to change the framework itself…

  19. Competitiveness - Higher Education

    National Research Council Canada - National Science Library

    Labas, Istvan; Darabos, Eva; Nagy, Tunde Orsolya

    2016-01-01

    ... economy. In recent years, the frameworks of operation of higher education systems have gone through a total transformation. The number of applying students is continuously decreasing in some European countries therefore only those institutions can "survive" this shortfall, which are able to minimize the loss of the number of students. In...

  20. Futurism in Higher Education.

    Science.gov (United States)

    Fazio, Linda S.

    1988-01-01

    The concept of "futurism" in higher education program planning, self-study and goal setting is taking on increasing significance. Two research techniques for "futures forecasting" are discussed: the Delphi and the Scenario. These techniques have been used successfully in institutional self-study and program evaluation.…

  1. Higher-Order Hierarchies

    DEFF Research Database (Denmark)

    Ernst, Erik

    2003-01-01

    This paper introduces the notion of higher-order inheritance hierarchies. They are useful because they provide well-known benefits of object-orientation at the level of entire hierarchies-benefits which are not available with current approaches. Three facets must be adressed: First, it must...

  2. The effect of N-stearoylethanolamine on cholesterol content, fatty acid composition and protein carbonylation level in rats with alimentary obesity-induced insulin resistance

    Directory of Open Access Journals (Sweden)

    O. V. Onopchenko

    2014-12-01

    Full Text Available The effect of N-stearoylethanolamine (NSE on liver free fatty acid composition, cholesterol content and carbonylated protein level in rats with obesity-induced insulin resistance (IR was studied in the work. The experimental insulin resistance was induced by prolonged high fat diet (58% of energy derived from fat for 6 months combined with one injection of low-dose (15 mg/kg of streptozotocin. The lipid assay showed a rise in liver free cholesterol content and a significant reduction in cholesterol esters level. Analyzing liver fatty acid composition, a decrease in polyunsaturated of fatty acid (PUFA level and an increase in monounsaturated fatty acid (MUFA content was found. Fatty acid imbalance with high content of MUFA was associated with elevated level of protein carbonylation. The NSE administration (50 mg/kg of body weight for 2 weeks decreased free cholesterol content, increased cholesterol esters level and reduced free oleic fatty acid content in the liver of rats with IR. The effect of NSE on lipid imbalance led to a decrease in protein carbonylation level that may result in improvement of transmembrane protein function under obesity-induced insulin resistance state.

  3. Carbonyl-ruthenium substituted alpha-Keggin-tungstosilicate, [alpha-SiW(11)O(39)Ru(II)(CO)](6-): synthesis, structure, redox studies and reactivity.

    Science.gov (United States)

    Sadakane, Masahiro; Iimuro, Yoshifumi; Tsukuma, Daisuke; Bassil, Bassem S; Dickman, Michael H; Kortz, Ulrich; Zhang, Yi; Ye, Shen; Ueda, Wataru

    2008-12-21

    The carbonyl-ruthenium substituted undecatungstosilicate [alpha-SiW(11)O(39)Ru(II)(CO)](6-) () was isolated as a caesium salt and successfully characterized by using (183)W and (13)C NMR, elemental analysis, IR, UV-vis and cyclic voltammetry (CV). Polyanion represents the first example of a metal-carbonyl moiety being fully incorporated into the polyoxometalate (POM). As a result, the Ru(CO) moiety became redox active and was reversibly oxidized to the one-electron ruthenium(iii) derivative, [alpha-SiW(11)O(39)Ru(III)(CO)](5-). This Ru(III)(CO) moiety was unexpectedly stable in aqueous solution compared to the organo-ruthenium carbonyl derivatives and could be detected by using UV-vis and in situ IR coupled with electrolysis. The oxidized ruthenium(iii) derivative slowly released CO in aqueous solution, resulting in the aqua species [alpha-SiW(11)O(39)Ru(III)(H(2)O)](5-) and then the dimeric POM species by condensation. Furthermore, could be converted to the corresponding aqua polyanion by photo-irradiation.

  4. Characterization of Odorous Compounds (VOC and Carbonyl Compounds in the Ambient Air of Yeosu and Gwangyang, Large Industrial Areas of South Korea

    Directory of Open Access Journals (Sweden)

    Young-Kyo Seo

    2014-01-01

    Full Text Available Odorous compounds play an important role in air pollution in industrial areas and the residential areas surrounding them. This study measured the odorous volatile organic compounds (VOC and carbonyl compounds at Yeosu and Gwangyang, two large industrial areas of South Korea, during four seasons of 2008-2009. Along with these two cities, the same odorous compounds were measured at Suncheon, which was selected as a control site. The concentrations of VOC and carbonyl compounds that were listed as odorous air pollutants by the Ministry of Environment of South Korea are discussed. Benzene and formaldehyde were included in the target analytes because of their carcinogenic nature. Most researchers only examined the concentration of odorous compounds in ambient air but the present study evaluated the odor intensity, which is a new parameter that will help better understand the precise odor perceived by people. This paper describes the seasonal variations and spatial distribution of the above-mentioned odorous compounds at the specified sites. Pearson correlation coefficients between the odorous compounds and other air pollutants, such as ozone, CO, SO2, NO2, and PM10, and meteorological conditions, such as temperature and wind speed, provide the source information of odorous VOC and carbonyl compounds.

  5. Characterization of odorous compounds (VOC and carbonyl compounds) in the ambient air of Yeosu and Gwangyang, large industrial areas of South Korea.

    Science.gov (United States)

    Seo, Young-Kyo; Suvarapu, Lakshmi Narayana; Baek, Sung-Ok

    2014-01-01

    Odorous compounds play an important role in air pollution in industrial areas and the residential areas surrounding them. This study measured the odorous volatile organic compounds (VOC) and carbonyl compounds at Yeosu and Gwangyang, two large industrial areas of South Korea, during four seasons of 2008-2009. Along with these two cities, the same odorous compounds were measured at Suncheon, which was selected as a control site. The concentrations of VOC and carbonyl compounds that were listed as odorous air pollutants by the Ministry of Environment of South Korea are discussed. Benzene and formaldehyde were included in the target analytes because of their carcinogenic nature. Most researchers only examined the concentration of odorous compounds in ambient air but the present study evaluated the odor intensity, which is a new parameter that will help better understand the precise odor perceived by people. This paper describes the seasonal variations and spatial distribution of the above-mentioned odorous compounds at the specified sites. Pearson correlation coefficients between the odorous compounds and other air pollutants, such as ozone, CO, SO2, NO2, and PM10, and meteorological conditions, such as temperature and wind speed, provide the source information of odorous VOC and carbonyl compounds.

  6. Self-aggregation behavior of synthetic zinc 3-hydroxymethyl-13/15-carbonyl-chlorins as models of main light-harvesting components in photosynthetic green bacteria.

    Science.gov (United States)

    Tamiaki, Hitoshi; Yoshimura, Hideaki; Shimamura, Yasuhide; Kunieda, Michio

    2008-01-01

    Zinc complexes of 3-hydroxymethyl-13/15-carbonyl-chlorins having a six-membered lactone as the E-ring were prepared by modifying purpurin-18 as models of bacteriochlorophyll-d, one of the chlorophyllous pigments in the main light-harvesting antenna systems (chlorosomes) of green photosynthetic bacteria. The synthetic 13-carbonylated compound self-aggregated in 1%(v/v) tetrahydrofuran and hexane to give large oligomers possessing red-shifted and broadened electronic absorption bands and intense circular dichroism bands at the shifted Q ( y ) region, indicating that the supramolecular structure of the resulting self-aggregate was similar to those of natural and artificial chlorosomal aggregates. The red-shift value observed here was smaller than the reported values in chlorosomal pigments having a five-membered keto-ring, which was ascribable to a weaker intermolecular hydrogen-bonding of 13-C=O with 3(1)-OH in a supramolecule of the former self-aggregate and suppression of the pi-pi interaction among the composite chlorins. On the other hand, the isomeric 15-carbonylated molecule was monomeric even in the nonpolar organic solvent, confirming the reported proposal that the linear orientation of three interactive moieties, OH, C=O and Zn, in a molecule is requisite for its chlorosomal self-aggregation.

  7. Higher spins and holography

    Science.gov (United States)

    Kraus, Per; Ross, Simon F.

    2013-05-01

    The principles of quantum mechanics and relativity impose rigid constraints on theories of massless particles with nonzero spin. Indeed, Yang-Mills theory and General Relativity are the unique solution in the case of spin-1 and spin-2. In asymptotically flat spacetime, there are fundamental obstacles to formulating fully consistent interacting theories of particles of spin greater than 2. However, indications are that such theories are just barely possible in asymptotically anti-de Sitter or de Sitter spacetimes, where the non-existence of an S-matrix provides an escape from the theorems restricting theories in Minkowski spacetime. These higher spin gravity theories are therefore of great intrinsic interest, since they, along with supergravity, provide the only known field theories generalizing the local invariance principles of Yang-Mills theory and General Relativity. While work on higher spin gravity goes back several decades, the subject has gained broader appeal in recent years due to its appearance in the AdS/CFT correspondence. In three and four spacetime dimensions, there exist duality proposals linking higher spin gravity theories to specific conformal field theories living in two and three dimensions respectively. The enlarged symmetry algebra of the conformal field theories renders them exactly soluble, which makes them excellent laboratories for understanding in detail the holographic mechanism behind AdS/CFT duality. Steady progress is also being made on better understanding the space of possible higher spin gravity theories and their physical content. This work includes classifying the possible field multiplets and their interactions, constructing exact solutions of the nonlinear field equations, and relating higher spin theories to string theory. A full understanding of these theories will involve coming to grips with the novel symmetry principles that enlarge those of General Relativity and Yang-Mills theory, and one can hope that this will provide

  8. Competitiveness - higher education

    Directory of Open Access Journals (Sweden)

    Labas Istvan

    2016-03-01

    Full Text Available Involvement of European Union plays an important role in the areas of education and training equally. The member states are responsible for organizing and operating their education and training systems themselves. And, EU policy is aimed at supporting the efforts of member states and trying to find solutions for the common challenges which appear. In order to make our future sustainable maximally; the key to it lies in education. The highly qualified workforce is the key to development, advancement and innovation of the world. Nowadays, the competitiveness of higher education institutions has become more and more appreciated in the national economy. In recent years, the frameworks of operation of higher education systems have gone through a total transformation. The number of applying students is continuously decreasing in some European countries therefore only those institutions can “survive” this shortfall, which are able to minimize the loss of the number of students. In this process, the factors forming the competitiveness of these budgetary institutions play an important role from the point of view of survival. The more competitive a higher education institution is, the greater the chance is that the students would like to continue their studies there and thus this institution will have a greater chance for the survival in the future, compared to ones lagging behind in the competition. Aim of our treatise prepared is to present the current situation and main data of the EU higher education and we examine the performance of higher education: to what extent it fulfils the strategy for smart, sustainable and inclusive growth which is worded in the framework of Europe 2020 programme. The treatise is based on analysis of statistical data.

  9. Increased levels of oxidative and carbonyl stress markers in normal ovarian cortex surrounding endometriotic cysts.

    Science.gov (United States)

    Di Emidio, Giovanna; D'Alfonso, Angela; Leocata, Pietro; Parisse, Valentina; Di Fonso, Adina; Artini, Paolo Giovanni; Patacchiola, Felice; Tatone, Carla; Carta, Gaspare

    2014-11-01

    Many evidence support the view that endometriotic cyst may exert detrimental effect on the surrounding ovarian microenvironment so representing a risk to functionality of adjacent follicles. Patients with benign ovarian cyst (endometriotic, follicular and dermoid cysts) subjected to laparoscopic cystectomy were enrolled in the present retrospective study in order to analyze whether endometriotic tissue could negatively affect the surrounding normal ovarian cortex more severely than other ovarian cysts. To this end we carried out immunohistochemistry analysis and comparative determination of the transcription factor FOXO3A, oxidized DNA adduct 8-OHdG (8-hydroxy-2'-deoxyguanosine) and damaged proteins known as AGEs (Advanced Glycation End products) as markers of ovarian stress response and molecular damage. Our results show that all the markers analyzed were present in normal ovarian tissue surrounding benign cysts. We observed higher levels of FOXO3A (15.90 ± 0.28), 8-OHdG (13.33 ± 2.07) and AGEs (12.58 ± 4.34) staining in normal ovarian cortex surrounding endometriotic cysts in comparison with follicular cysts (9.04 ± 0.29, 2.67 ± 2.67, 11.31 ± 2.95, respectively) and dermoid cysts (2.02 ± 0.18, 4.33 ± 2.58 and 10.56 ± 4.03, respectively). These results provide evidence that ovarian endometrioma is responsible for more severe alterations to cellular biomolecules than follicular and dermoid cysts.

  10. Chiral higher spin gravity

    Science.gov (United States)

    Krishnan, Chethan; Raju, Avinash

    2017-06-01

    We construct a candidate for the most general chiral higher spin theory with AdS3 boundary conditions. In the Chern-Simons language, on the left it has the Drinfeld-Sokolov reduced form, but on the right all charges and chemical potentials are turned on. Altogether (for the spin-3 case) these are 19 functions. Despite this, we show that the resulting metric has the form of the "most general" AdS3 boundary conditions discussed by Grumiller and Riegler. The asymptotic symmetry algebra is a product of a W3 algebra on the left and an affine s l (3 )k current algebra on the right, as desired. The metric and higher spin fields depend on all the 19 functions. We compare our work with previous results in the literature.

  11. Gamification in higher education

    OpenAIRE

    Langendahl, Per-Anders; Cook, Matthew; Mark-Herbert, Cecilia

    2016-01-01

    This report explores gamification as a pedagogic approach to engage and motivate students in higher education. Gamification is understood here to be the use of game elements in non-game contexts. Here game elements correspond to the characteristics of games, and context is defined as the activity and setting gamified. Gamification is deployed in various contexts such as running, shopping and learning and is therefore an open and multifaceted concept with multiple applications. The report deve...

  12. Gas to particle conversion-gas exchange technique for direct analysis of metal carbonyl gas by inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Nishiguchi, Kohei; Utani, Keisuke; Gunther, Detlef; Ohata, Masaki

    2014-10-21

    A novel gas to particle conversion-gas exchange technique for the direct analysis of metal carbonyl gas by inductively coupled plasma mass spectrometry (ICPMS) was proposed and demonstrated in the present study. The technique is based on a transfer of gas into particle, which can be directly analyzed by ICPMS. Particles from metal carbonyl gases such as Cr(CO)6, Mo(CO)6, and W(CO)6 are formed by reaction with ozone (O3) and ammonium (NH3) gases within a newly developed gas to particle conversion device (GPD). The reaction mechanism of the gas to particle conversion is based on either oxidation of metal carbonyl gas by O3 or agglomeration of metal oxide with ammonium nitrate (NH4NO3) which is generated by the reaction of O3 and NH3. To separate the reaction gases (remaining O3 and NH3) from the formed particles, a previously reported gas exchange device (GED) was used and the in argon stabilized analyte particles were directly introduced and measured by ICPMS. This new technique provided limits of detection (LOD) of 0.15 pL L(-1) (0.32 ng m(-3)), 0.02 pL L(-1) (0.07 ng m(-3)), and 0.01 pL L(-1) (0.07 ng m(-3)) for Cr(CO)6, Mo(CO)6, and W(CO)6, respectively, which were 4-5 orders of magnitude lower than those conventional applied for detecting these gases, e.g., gas chromatography with electron captured detector (GC-ECD) as well as Fourier transform-infrared spectroscopy (FT-IR). The achieved LODs were also similar or slightly better than those for ICPMS coupled to GC. Since the gas to particle conversion technique can achieve the direct measurement of metal carbonyl gases as well as the removal of reaction and ambient gases from metal carbonyl gases, the technique is considered to be well suited to monitor gas quality in semiconductor industry, engine exhaust gases, and or waste incineration products.

  13. The role of carbonyl sulphide as a source of stratospheric sulphate aerosol and its impact on climate

    Directory of Open Access Journals (Sweden)

    C. Brühl

    2012-02-01

    Full Text Available Globally, carbonyl sulphide (COS is the most abundant sulphur gas in the atmosphere. Our chemistry-climate model (CCM of the lower and middle atmosphere with aerosol module realistically simulates the background stratospheric sulphur cycle, as observed by satellites in volcanically quiescent periods. The model results indicate that upward transport of COS from the troposphere largely controls the sulphur budget and the aerosol loading of the background stratosphere. This differs from most previous studies which indicated that short-lived sulphur gases are also important. The model realistically simulates the modulation of the particulate and gaseous sulphur abundance in the stratosphere by the quasi-biennial oscillation (QBO. In the lowermost stratosphere organic carbon aerosol contributes significantly to extinction. Further, using a chemical radiative convective model and recent spectra, we compute that the direct radiative forcing efficiency by 1 kg of COS is 724 times that of 1 kg CO2. Considering an anthropogenic fraction of 30% (derived from ice core data, this translates into an overall direct radiative forcing by COS of 0.003 W m−2. The direct global warming potentials of COS over time horizons of 20 and 100 yr are GWP(20 yr = 97 and GWP(100 yr = 27, respectively (by mass. Furthermore, stratospheric aerosol particles produced by the photolysis of COS (chemical feedback contribute to a negative direct solar radiative forcing, which in the CCM amounts to −0.007 W m−2 at the top of the atmosphere for the anthropogenic fraction, more than two times the direct warming forcing of COS. Considering that the lifetime of COS is twice that of stratospheric aerosols the warming and cooling tendencies approximately cancel.

  14. Dynamics of canopy stomatal conductance, transpiration, and evaporation in a temperate deciduous forest, validated by carbonyl sulfide uptake

    Science.gov (United States)

    Wehr, Richard; Commane, Róisín; Munger, J. William; McManus, J. Barry; Nelson, David D.; Zahniser, Mark S.; Saleska, Scott R.; Wofsy, Steven C.

    2017-01-01

    Stomatal conductance influences both photosynthesis and transpiration, thereby coupling the carbon and water cycles and affecting surface-atmosphere energy exchange. The environmental response of stomatal conductance has been measured mainly on the leaf scale, and theoretical canopy models are relied on to upscale stomatal conductance for application in terrestrial ecosystem models and climate prediction. Here we estimate stomatal conductance and associated transpiration in a temperate deciduous forest directly on the canopy scale via two independent approaches: (i) from heat and water vapor exchange and (ii) from carbonyl sulfide (OCS) uptake. We use the eddy covariance method to measure the net ecosystem-atmosphere exchange of OCS, and we use a flux-gradient approach to separate canopy OCS uptake from soil OCS uptake. We find that the seasonal and diurnal patterns of canopy stomatal conductance obtained by the two approaches agree (to within ±6 % diurnally), validating both methods. Canopy stomatal conductance increases linearly with above-canopy light intensity (in contrast to the leaf scale, where stomatal conductance shows declining marginal increases) and otherwise depends only on the diffuse light fraction, the canopy-average leaf-to-air water vapor gradient, and the total leaf area. Based on stomatal conductance, we partition evapotranspiration (ET) and find that evaporation increases from 0 to 40 % of ET as the growing season progresses, driven primarily by rising soil temperature and secondarily by rainfall. Counterintuitively, evaporation peaks at the time of year when the soil is dry and the air is moist. Our method of ET partitioning avoids concerns about mismatched scales or measurement types because both ET and transpiration are derived from eddy covariance data. Neither of the two ecosystem models tested predicts the observed dynamics of evaporation or transpiration, indicating that ET partitioning such as that provided here is needed to further

  15. Application of image-derived and venous input functions in major depression using [carbonyl-(11)C]WAY-100635.

    Science.gov (United States)

    Hahn, Andreas; Nics, Lukas; Baldinger, Pia; Wadsak, Wolfgang; Savli, Markus; Kraus, Christoph; Birkfellner, Wolfgang; Ungersboeck, Johanna; Haeusler, Daniela; Mitterhauser, Markus; Karanikas, Georgios; Kasper, Siegfried; Frey, Richard; Lanzenberger, Rupert

    2013-04-01

    Image-derived input functions (IDIFs) represent a promising non-invasive alternative to arterial blood sampling for quantification in positron emission tomography (PET) studies. However, routine applications in patients and longitudinal designs are largely missing despite widespread attempts in healthy subjects. The aim of this study was to apply a previously validated approach to a clinical sample of patients with major depressive disorder (MDD) before and after electroconvulsive therapy (ECT). Eleven scans from 5 patients with venous blood sampling were obtained with the radioligand [carbonyl-(11)C]WAY-100635 at baseline, before and after 11.0±1.2 ECT sessions. IDIFs were defined by two different image reconstruction algorithms 1) OSEM with subsequent partial volume correction (OSEM+PVC) and 2) reconstruction based modelling of the point spread function (TrueX). Serotonin-1A receptor (5-HT1A) binding potentials (BPP, BPND) were quantified with a two-tissue compartment (2TCM) and reference region model (MRTM2). Compared to MRTM2, good agreement in 5-HT1A BPND was found when using input functions from OSEM+PVC (R(2)=0.82) but not TrueX (R(2)=0.57, pderived and venous input functions defined by OSEM with subsequent PVC we confirm previously reported decreases in 5-HT1A binding in MDD patients after ECT. In contrast to reference region modeling, quantification with image-derived input functions showed consistent results in a clinical setting due to accurate modeling of non-specific binding with OSEM+PVC. Copyright © 2013 Elsevier Inc. All rights reserved.

  16. Investigation into the Effects of Boron on Liver Tissue Protein Carbonyl, MDA, and Glutathione Levels in Endotoxemia.

    Science.gov (United States)

    Balabanlı, Barbaros; Balaban, Tuba

    2015-10-01

    Endotoxin has been known to cause the formation and damage of free radical. The importance of boron for human life is increasing each passing day, and its consuming fields are continuing to expand due to the advances in science and technology. Therefore, in our study, we intended to investigate into the effects of boron on liver tissue oxidative events. Eighteen male Wistar albino rats were randomly separated into three equal groups in the experiments; control group, boron + endotoxin group, and endotoxin group. Dissolved in distilled water, boric acid (100 mg/kg) was administered to boron + endotoxin group via gavage procedure for 28 days. Only distilled water was administered to control and endotoxin groups via gavage procedure for 28 days. Then 4 mg/kg endotoxin (LPS; Escherichia coli 0111:B4) was intraperitoneally (ip) administered to boron + endotoxin and endotoxin groups on the 28th day. Sterile saline was injected into control group on the 28th day (ip). Malondialdehyde (MDA), which is the end product of lipid peroxidation in liver tissues, protein carbonyl compounds (PC), which are protein oxidization markers, and glutathione (GSH) levels were measured spectrophotometrically. The results were compared with Mann-Whitney U test. When boron + endotoxin group is compared with endotoxin group, PC levels of endotoxin group showed a significant increase. When GSH levels are compared, GSH level in boron + endotoxin group decreased according to endotoxin group. Variations among all groups in MDA levels were found to be statistically insignificant. We are of the opinion that endotoxin affects the proteins by forming free radicals, and boron may also cause the structural and/or functional changes in proteins in order to protect proteins from oxidization.

  17. Engineering of Corynebacterium glutamicum to utilize methyl acetate, a potential feedstock derived by carbonylation of methanol with CO.

    Science.gov (United States)

    Choo, Seungjung; Um, Youngsoon; Han, Sung Ok; Woo, Han Min

    2016-04-20

    The possibilities to utilize one-carbon substrates (C1) like CO, methane and methanol have been explored as a cheap alternative feedstock in the biotechnology. For the first time, methyl acetate (MeOAc), which can be formed from carbonylation of methanol with CO, was demonstrated to be an alternative carbon source for the cell growth of Corynebacterium glutamicum as a model microbial cell factory. To do so, a carboxyl esterase activity was necessary to hydrolyze MeOAc to methanol and acetate. Although the wild-type has an unknown esterase activity to MeOAc, the activity was not high enough to grow from 270mM MeOAc as sole carbon source, reaching OD600 of 5.28±0.2 in 32h. Based on the literatures studied for the esterase, we chose three esterases (MekB of Pseudomonas veronii MEK700, AcmB of Gordonia sp. Strain TY-5, and Est of Pyrobaculum calidifontis VA1) and cloned into the wild-type. As a result, the recombinant C. glutamicum expressing the highly active MekB esterase (28.6±0.77U/mg protein) showed complete degradation of MeOAc and utilization of acetate, resulting in OD600 of 16.5±0.02at 24h. In addition, the recombinant strain exhibited the rapid degradation of MeOAc to methanol and acetate in 2h under anaerobic condition. Therefore, MeOAc can be used as another C1-derived carbon source in the biotechnology. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Continuous In-situ Measurements of Carbonyl Sulfide (OCS) and Carbon Dioxide Isotopes to Constrain Ecosystem Carbon and Water Exchanges

    Science.gov (United States)

    Rastogi, B.; Still, C. J.; Noone, D. C.; Berkelhammer, M. B.; Whelan, M.; Lai, C. T.; Hollinger, D. Y.; Gupta, M.; Leen, J. B.; Huang, Y. W.

    2015-12-01

    Understanding the processes that control the terrestrial exchange of carbon and water are critical for examining the role of forested ecosystems in changing climates. A small but increasing number of studies have identified Carbonyl Sulfide (OCS) as a potential tracer for photosynthesis. OCS is hydrolyzed by an irreversible reaction in leaf mesophyll cells that is catalyzed by the enzyme, carbonic anhydrase. Leaf- level field and greenhouse studies indicate that OCS uptake is controlled by stomatal activity and that the ratio of OCS and CO2 uptake is reasonably constant. Existing studies on ecosystem OCS exchange have been based on laboratory measurements or short field campaigns and therefore little information on OCS exchange in a natural ecosystem over longer timescales is available. The objective of this study is to further assess the stability of OCS as a tracer for canopy photosynthesis in an active forested ecosystem and also to assess its utility for constraining transpiration, since both fluxes are mediated by canopy stomatal conductance. An off-axis integrated cavity output spectroscopy analyzer (Los Gatos Research Inc.) was deployed at the Wind River Experimental Forest in Washington (45.8205°N, 121.9519°W). Canopy air was sampled from four heights as well as the soil to measure vertical gradients of OCS within the canopy, and OCS exchange between the forest and the atmosphere for the growing season. Here we take advantage of simultaneous measurements of the stable isotopologues of H2O and CO2 at corresponding heights as well as NEE (Net Ecosystem Exchange) from eddy covariance measurements to compare GPP (Gross Primary Production) and transpiration estimates from a variety of independent techniques. Our findings also seek to allow assessment of the environmental and ecophysicological controls on evapotranspiration rates, which are projected to change in coming decades, and are otherwise poorly constrained.

  19. Synthesis, characterization, electronic structure and catalytic activity of new ruthenium carbonyl complexes of N-[(2-pyridyl)methylidene]-2-aminothiazole

    Science.gov (United States)

    Kundu, Subhankar; Sarkar, Deblina; Jana, Mahendra Sekhar; Pramanik, Ajoy Kumar; Jana, Subrata; Mondal, Tapan Kumar

    2013-03-01

    Reaction of ruthenium carbonyls, [Ru(CO)2Cl2]n/[Ru(CO)4I2] with bidentate Schiffs base ligands derived by the condensation of pyridine-2-carboxaldehyde with 2-aminothiazole in a 1:1 mole ratio in acetonitrile led to the formation of complexes having general formula [Ru(CO)2(L)X2] (X = Cl (1) and I (2)) (L = N-[(2-pyridyl)methylidene]-2-aminothiazole). The compounds have been characterized by various analytical and spectroscopic (IR, electronic and 1H NMR) studies. In acetonitrile solution the complexes exhibit a weak broad metal-ligand to ligand charge transfer (MLLCT) band along with ILCT transitions. The compounds are emissive in room temperature upon excitation in the ILCT band. The complexes exhibit a quasi-reversible one electron Ru(II)/Ru(III) oxidation couple at 1.44 V for 1 and 0.94 V for 2. Catalytic activity of these compounds is investigated to the oxidation of PhCH2OH to PhCHO, 2-butanol (C4H9OH) to 2-butanone, 1-phenylethanol (PhC2H4OH) to acetophenone, cyclopentanol (C5H9OH) to cyclopentanone, cyclohexanol to cyclohexanone, cycloheptanol to cycloheptanone and cycloctanol to cycloctanone using N-methylmorpholine-N-oxide (NMO) as oxidant. The catalytic efficiency of 2 is greater than complex 1 and well correlate with the metal oxidation potential of the complexes. DFT, NBO and TDDFT calculations are employed to explain the structural and electronic features and to support the spectroscopic assignments.

  20. Screening of thiourea derivatives and carbonyl-2-aminothiazole derivatives for potential CCR4 antagonists using capillary zone electrophoresis.

    Science.gov (United States)

    Zhang, Shuyu; Qi, Hui; Yakufu, Pazilaiti; Zhao, Fang; Ling, Xiaomei; Xiao, Junhai; Wang, Ying

    2011-01-01

    CC chemokine receptor 4 (CCR4) is a kind of G-protein-coupled receptors with a characteristic seven-transmembrane structure and selectively expressed on Th2-type CD4+ T-cells. CCR4 has been identified as a potentially important drug target for the treatment of T cell-mediated allergic inflammatory diseases. In this study, a novel series of CCR4 antagonists were screened by investigating the interactions between the compounds and the human CCR4 N-terminal peptide ML40 using capillary zone electrophoresis (CZE) for the first time. Both qualitative and quantitative characterizations of the compound-peptide binding were determined. The results showed that, compared with positive control, ten of the compounds were interacted with ML40, which were A3C223, A3C231, A4C238, A3C241, A4C241, A4C239, ZXF0337, ZXF0432, ZXF0519 and ZXF0637A, and their binding constants were calculated from the Scatchard plot by regression. The binding constants of the compounds to ML40 were calculated and the binding constant of ZXF0432 was the largest among them [(7.6334±0.1907)×10(4)M(-1)]. Here, a sensitive and selective high-performance analytical method based on CZE was developed for screening of thiourea derivatives and C-arbonyl-2-aminothiazole derivatives for potential CCR4 antagonists for the first time. The methodology presented should be generally applicable to study compounds-ML40 interactions as a powerful, sensitive and fast screening method for CCR4 antagonist discovery. Copyright © 2010 Elsevier B.V. All rights reserved.

  1. Higher Education in Scandinavia

    DEFF Research Database (Denmark)

    Nielsen, Jørgen Lerche; Andreasen, Lars Birch

    2015-01-01

    Higher education systems around the world have been undergoing fundamental changes through the last 50 years from more narrow self-sustaining universities for the elite and into mass universities, where new groups of students have been recruited and the number of students enrolled has increased...... dramatically. In adjusting to the role of being a mass educational institution, universities have been challenged on how to cope with external pressures, such as forces of globalization and international markets, increased national and international competition for students and research grants, increased...... an impact on the educational systems in Scandinavia, and what possible futures can be envisioned?...

  2. Higher engineering mathematics

    CERN Document Server

    John Bird

    2014-01-01

    A practical introduction to the core mathematics principles required at higher engineering levelJohn Bird's approach to mathematics, based on numerous worked examples and interactive problems, is ideal for vocational students that require an advanced textbook.Theory is kept to a minimum, with the emphasis firmly placed on problem-solving skills, making this a thoroughly practical introduction to the advanced mathematics engineering that students need to master. The extensive and thorough topic coverage makes this an ideal text for upper level vocational courses. Now in

  3. Carbonyl sulfide (OCS) as a proxy for GPP: Complications derived from studies on the impact of CO2, soil humidity and sterilization on the OCS exchange between soils and atmosphere

    Science.gov (United States)

    Bunk, Rüdiger; Behrendt, Thomas; Yi, Zhigang; Kesselmeier, Jürgen

    2016-04-01

    Carbonyl sulfide is discussed to be used as a proxy for gross primary productivity (GPP) of forest ecosystems. However, soils may interfere. Soils play an important role in budgeting global and local carbonyl sulfide (OCS) fluxes, yet the available data on the uptake and emission behavior of soils in conjunction with environmental factors is limited. The work of many authors has shown that the OCS exchange of soils depends on various factors, such as soil type, atmospheric OCS concentrations, temperature or soil water content (Kesselmeier et al., J. Geophys. Res., 104, No. D9, 11577-11584, 1999; Van Diest & Kesselmeier, Biogeosciences, 5, 475-483, 2008; Masyek et al., PNAS, 111, No 25, 9064-9069, doi: 10.1073/pnas.1319132111, 2014; Whelan and Rhew, J. Geophys. Res. Biogeosciences., 120, 54-62, doi: 10.1002/2014JG002661, 2015) and the light dependent and obviously abiotic OCS production as reported by Whelan and Rhew (2015). To get a better constraint on the impact of some environmental factors on the OCS exchange of soils we used a new laser based integrated cavity output spectroscopy instrument (LGR COS/CO Analyzer Model 907-0028, Los Gatos, Mountain View, California, USA) in conjunction with an automated soil chamber system (as described in Behrendt et al, Biogeosciences, 11, 5463-5492, doi: 10.5194/bg-11-5463-2014, 2014). The OCS exchange of various soils under the full range of possible soil humidity and various CO2 mixing ratios was examined. Additionally OCS exchange of chloroform sterilized subsamples was compared to their live counterparts to illuminate the influence of microorganisms. Results were quite heterogeneous between different soils. With few exceptions, all examined soils show dependence between OCS exchange and soil humidity, usually with strongest uptake at a certain humidity range and less uptake or even emission at higher and lower humidity. Differences in CO2 mixing ratio also clearly impacts on OCS exchange, but trends for different soils

  4. Towards higher intensities

    CERN Multimedia

    CERN Bulletin

    2010-01-01

    Over the past 2 weeks, commissioning of the machine protection system has advanced significantly, opening up the possibility of higher intensity collisions at 3.5 TeV. The intensity has been increased from 2 bunches of 1010 protons to 6 bunches of 2x1010 protons. Luminosities of 6x1028 cm-2s-1 have been achieved at the start of fills, a factor of 60 higher than those provided for the first collisions on 30 March.   The recent increase in LHC luminosity as recorded by the experiments. (Graph courtesy of the experiments and M. Ferro-Luzzi) To increase the luminosity further, the commissioning crews are now trying to push up the intensity of the individual proton bunches. After the successful injection of nominal intensity bunches containing 1.1x1011 protons, collisions were subsequently achieved at 450 GeV with these intensities. However, half-way through the first ramping of these nominal intensity bunches to 3.5 TeV on 15 May, a beam instability was observed, leading to partial beam loss...

  5. Carbonyl iron reduces anemia and improves effectiveness of treatment in under six-year-old children Ferro carbonila reduz anemia e melhora a efetividade do tratamento de crianças menores de 6 anos de idade

    Directory of Open Access Journals (Sweden)

    Iria L. G. Farias

    2009-01-01

    Full Text Available The treatment of iron deficiency anemia in children usually consists in the use of ferrous sulfate solution, but this treatment does not always have the desired effectiveness. The aim of this study was to evaluate the effectiveness of chewable carbonyl iron tablets as an alternative for the treatment of iron deficiency anemia in under six-year-old children. Seventy-three children from Brazilian Family Health Units in Santa Maria, Brazil, were included in this study. One group received chewable carbonyl iron (CI tablets and a control group received a solution of ferrous sulfate (FS for 90 days, both at a dose of 5 mg/Kg/day. Blood was drawn from study participants at 0, 30 and 90 days of treatment to evaluate the whole blood test, ferritin concentration, serum iron, and total iron binding capacity. We also evaluated the acceptance and adherence to treatment, and the occurrence of side effects during treatment. Hemoglobin increased 1.3 g/dL in the CI Group and 1.2 g/dL in the FS group during the first 30 days of treatment. After 90 days of treatment, the CI Group had significantly better results for hematocrit, MCV, MCH, iron binding capacity and ferritin concentration compared to the FS Group. The ferritin concentration was significantly higher in the CI Group at the end of the treatment (9.51 ng/mL to 26.16 ng/mL. Additionally, the treatment was better accepted with fewer adverse effects by this group. Chewable carbonyl iron tablets should be considered an important therapeutic option in the treatment of iron deficiency anemia of under six-year-old children.O tratamento da anemia ferropriva de crianças consiste, em sua maioria, no uso de solução de sulfato ferroso e este tratamento nem sempre apresenta a efetividade desejada. O objetivo deste estudo foi avaliar a efetividade do ferro carbonila, na forma de comprimidos mastigáveis, como uma alternativa de tratamento para anemia ferropriva de crianças menores de seis anos de idade. Foram

  6. Teaching at higher levels

    Science.gov (United States)

    1998-11-01

    Undergraduate physics programmes for the 21st century were under discussion at a recent event held in Arlington, USA, open to two or three members of the physics faculties of universities from across the whole country. The conference was organized by the American Association of Physics Teachers with co-sponsorship from the American Institute of Physics, the American Physical Society and Project Kaleidoscope. Among the various aims were to learn about physics departments that have successfully revitalized their undergraduate physics programmes with innovative introductory physics courses and multi-track majors programmes. Engineers and life scientists were to be asked directly how physics programmes can better serve their students, and business leaders would be speaking on how physics departments can help to prepare their students for the diverse careers that they will eventually follow. It was planned to highlight ways that departments could fulfil their responsibilities towards trainee teachers, to identify the resources needed for revitalizing a department's programme, and to develop guidelines and recommendations for a funding programme to support collaborative efforts among physics departments for carrying out the enhancements required. More details about the conference can be found on the AAPT website (see http://www.aapt.org/programs/rupc.html). Meanwhile the UK's Higher Education Funding Council has proposed a two-pronged approach to the promotion of high quality teaching and learning, as well as widening participation in higher education from 1999-2000. A total of £60m should be available to support these initiatives by the year 2001-2002. As part of this scheme the Council will invite bids from institutions to support individual academics in enhancing learning and teaching, as well as in recognition of individual excellence. As with research grants, such awards would enable staff to pursue activities such as the development of teaching materials

  7. Design new P-glycoprotein modulators based on molecular docking and CoMFA study of α, β-unsaturated carbonyl-based compounds and oxime analogs as anticancer agents

    Science.gov (United States)

    Sepehri, Bakhtyar; Ghavami, Raouf

    2017-02-01

    In this research, molecular docking and CoMFA were used to determine interactions of α, β-unsaturated carbonyl-based compounds and oxime analogs with P-glycoprotein and prediction of their activity. Molecular docking study shown these molecules establish strong Van der Waals interactions with side chain of PHE-332, PHE-728 and PHE-974. Based on the effect of component numbers on squared correlation coefficient for cross validation tests (including leave-one-out and leave-many-out), CoMFA models with five components were built to predict pIC50 of molecules in seven cancer cell lines (including Panc-1 (pancreas cancer cell line), PaCa-2 (pancreatic carcinoma cell line), MCF-7 (breast cancer cell line), A-549 (epithelial), HT-29 (colon cancer cell line), H-460 (lung cancer cell line), PC-3 (prostate cancer cell line)). R2 values for training and test sets were in the range of 0.94-0.97 and 0.84 to 0.92, respectively, and for LOO and LMO cross validation test, q2 values were in the range of 0.75-0.82 and 0.65 to 0.73, respectively. Based on molecular docking results and extracted steric and electrostatic contour maps for CoMFA models, four new molecules with higher activity with respect to the most active compound in data set were designed.

  8. DeNO{sub x} reaction studies. Reactivity of carbonyl or nitro-compounds compared to C{sub 3}H{sub 6}. Influence of adsorbed species in N{sub 2} and N{sub 2}O formation

    Energy Technology Data Exchange (ETDEWEB)

    Oulad Haj, Khadija; Ziyade, Souad; Ziyad, Mahfoud [Laboratoire d' Etude Physico-Chimiques des Materiaux et Catalyse, Faculte des Sciences, Avenue Ibn Batouta, Rabat (Morocco); Garin, Francois [Laboratoire des Materiaux, Surfaces et Procedes pour la Catalyse LMSPC UMR 7515 du CNRS, ECPM, 25, Rue Becquerel, 67087 Cedex 2 Srasbourg (France)

    2002-04-08

    There is not yet a straightforward answer concerning the mechanism(s) of selective catalytic reduction of NO{sub x} by hydrocarbons. In this study, a systematic approach of this reaction was undertaken over 0.5wt.% Pd/Al{sub 2}O{sub 3}. Successively, oxygen, NO and C{sub 3}H{sub 6}, which is the reductant, were either suppressed or substituted by NO{sub 2}, acetone, propanal, 1- or 2-nitropropane. A 'memory effect', i.e. N{sub 2} formation in (NO+O{sub 2}) after (NO+O{sub 2}+C{sub 3}H{sub 6}) reaction, was observed. Moreover, a concurrence exists between the overshoot in the CO{sub 2} formation and N{sub 2} formation peaks in (NO+O{sub 2}+C{sub 3}H{sub 6}) reaction under transient conditions, continuously raising the temperature. The more the reactants were adsorbed, the higher the nitrogen production amount was. To interpret these results, strong adsorption phenomena have to be invoked. >From the results obtained with the use of carbonyl and nitro-compounds, it seems that both species may be involved in the DeNO{sub x} reaction mechanisms.

  9. Higher Order Mode Fibers

    DEFF Research Database (Denmark)

    Israelsen, Stine Møller

    This PhD thesis considers higher order modes (HOMs) in optical fibers. That includes their excitation and characteristics. Within the last decades, HOMs have been applied both for space multiplexing in optical communications, group velocity dispersion management and sensing among others....... The research presented in this thesis falls in three parts. In the first part, a first time demonstration of the break of the azimuthal symmetry of the Bessel-like LP0X modes is presented. This effect, known as the bowtie effect, causes the mode to have an azimuthal dependence as well as a quasi......-radial polarization as opposed to the linear polarization of the LP0X modes. The effect is investigated numerically in a double cladding fiber with an outer aircladding using a full vectorial modesolver. Experimentally, the bowtie modes are excited using a long period grating and their free space characteristics...

  10. Thiophene-2-carbonyl azide

    Directory of Open Access Journals (Sweden)

    Michael Findlater

    2013-08-01

    Full Text Available The title compound, C5H3N3OS, is almost planar (r.m.s. deviation for the ten non-H atoms = 0.018 Å and forms an extended layer structure in the (100 plane, held together via hydrogen-bonding interactions between adjacent molecules. Of particular note is the occurrence of RC—H...N−=N+=NR interactions between an aromatic C—H group and an azide moiety which, in conjunction with a complementary C—H...O=C interaction, forms a nine-membered ring.

  11. Higher oxidative stress in skeletal muscle of McArdle disease patients

    Directory of Open Access Journals (Sweden)

    Jan J. Kaczor

    2017-09-01

    Full Text Available McArdle disease (MCD is an autosomal recessive condition resulting from skeletal muscle glycogen phosphorylase deficiency. The resultant block in glycogenolysis leads to an increased flux through the xanthine oxidase pathway (myogenic hyperuricemia and could lead to an increase in oxidative stress. We examined markers of oxidative stress (8-isoprostane and protein carbonyls, NAD(PH-oxidase, xanthine oxidase and antioxidant enzyme (superoxide dismutase, catalase and glutathione peroxidase activity in skeletal muscle of MCD patients (N = 12 and controls (N = 12. Eight-isoprostanes and protein carbonyls were higher in MCD patients as compared to controls (p < 0.05. There was a compensatory up-regulation of catalase protein content and activity (p < 0.05, mitochondrial superoxide dismutase (MnSOD protein content (p < 0.01 and activity (p < 0.05 in MCD patients, yet this increase was not sufficient to protect the muscle against elevated oxidative damage. These results suggest that oxidative stress in McArdle patients occurs and future studies should evaluate a potential role for oxidative stress contributing to acute pathology (rhabdomyolysis and possibly later onset fixed myopathy.

  12. Learning higher mathematics

    CERN Document Server

    Pontrjagin, Lev Semenovič

    1984-01-01

    Lev Semenovic Pontrjagin (1908) is one of the outstanding figures in 20th century mathematics. In a long career he has made fundamental con­ tributions to many branches of mathematics, both pure and applied. He has received every honor that a grateful government can bestow. Though in no way constrained to do so, he has through the years taught mathematics courses at Moscow State University. In the year 1975 he set himself the task of writing a series of books on secondary school and beginning university mathematics. In his own words, "I wished to set forth the foundations of higher mathematics in a form that would have been accessible to myself as a lad, but making use of all my experience as a scientist and a teacher, ac­ cumulated over many years. " The present volume is a translation of the first two out of four moderately sized volumes on this theme planned by Pro­ fessor Pontrjagin. The book begins at the beginning of modern mathematics, analytic ge­ ometry in the plane and 3-dimensional space. Refin...

  13. Combining in situ and laboratory measurements of soil-atmosphere carbonyl sulfide fluxes from four different biomes across Europe

    Science.gov (United States)

    Kitz, Florian; Gomez-Brandon, Maria; Hammerle, Albin; Spielmann, Felix M.; Insam, Heribert; Ibrom, Andreas; Migliavacca, Mirco; Moreno, Gerardo; Noe, Steffen M.; Wohlfahrt, Georg

    2017-04-01

    Flux partitioning, the quantification of photosynthesis and respiration, is a major uncertainty in modelling the carbon cycle and in times when robust models are needed to assess future global changes a persistent problem. A promising new approach is to derive gross primary production (GPP) from measurements of the carbonyl sulfide (COS) flux, the most abundant sulfur-containing trace gas in the atmosphere, with a mean concentration of about 500 pptv in the troposphere. This is possible because COS and CO2 enter the leaf via a similar pathway and are processed by the same enzyme (carbonic anhydrase). A prerequisite for using COS as a proxy for photosynthesis is a robust estimation of all non-leaf sources and sinks in an ecosystem. Past studies described soils either as a sink or source, depending on their properties like soil temperature and soil water content. In 2016 we conducted field campaigns in Austria (managed temperate mountain grassland), Spain (savannah), Denmark (temperate beech forest) and Estonia (hemiboreal forest) to estimate the soil-atmosphere COS fluxes under ambient conditions in different biomes. We used self-built fused silica soil chambers to avoid COS emissions from built-in materials and to assess the impact of radiation. At the grassland sites (Austria, Spain) vegetation was removed below the chambers, therefor more radiation reached the soil surface compared to natural conditions. The grassland sites were characterized by highly positive COS fluxes during daytime and COS fluxes around zero during nighttime. In contrast, the soils at the forest sites (Denmark, Estonia), characterized by less radiation on the soil surface, acted as a sink for COS. The impact of other abiotic factors, like soil water content and soil temperature, varied between the ecosystems. In addition to the field measurements soil and litter samples were taken at the study sites and used to measure COS fluxes under controlled conditions in the lab. Results from the

  14. A top-down approach of surface carbonyl sulfide exchange by a Mediterranean oak forest ecosystem in southern France

    Directory of Open Access Journals (Sweden)

    S. Belviso

    2016-12-01

    Full Text Available The role that soil, foliage, and atmospheric dynamics have on surface carbonyl sulfide (OCS exchange in a Mediterranean forest ecosystem in southern France (the Oak Observatory at the Observatoire de Haute Provence, O3HP was investigated in June of 2012 and 2013 with essentially a top-down approach. Atmospheric data suggest that the site is appropriate for estimating gross primary production (GPP directly from eddy covariance measurements of OCS fluxes, but it is less adequate for scaling net ecosystem exchange (NEE to GPP from observations of vertical gradients of OCS relative to CO2 during the daytime. Firstly, OCS and carbon dioxide (CO2 diurnal variations and vertical gradients show no net exchange of OCS at night when the carbon fluxes are dominated by ecosystem respiration. This contrasts with other oak woodland ecosystems of a Mediterranean climate, where nocturnal uptake of OCS by soil and/or vegetation has been observed. Since temperature, water, and organic carbon content of soil at the O3HP should favor the uptake of OCS, the lack of nocturnal net uptake would indicate that its gross consumption in soil is compensated for by emission processes that remain to be characterized. Secondly, the uptake of OCS during the photosynthetic period was characterized in two different ways. We measured ozone (O3 deposition velocities and estimated the partitioning of O3 deposition between stomatal and non-stomatal pathways before the start of a joint survey of OCS and O3 surface concentrations. We observed an increasing trend in the relative importance of the stomatal pathway during the morning hours and synchronous steep drops of mixing ratios of OCS (amplitude in the range of 60–100 ppt and O3 (amplitude in the range of 15–30 ppb after sunrise and before the break up of the nocturnal boundary layer. The uptake of OCS by plants was also characterized from vertical profiles. However, the time window for calculation of the ecosystem relative

  15. Metal complexes with 1,2-dithione ligands. 3. Dithiooxamides as strong donors or acceptors in molybdenum carbonyl complexes

    Energy Technology Data Exchange (ETDEWEB)

    Dieck, H.T.; Form, M. (Hamburg Univ. (Germany, F.R.))

    1984-08-01

    Starting from substitution labile molybdenum carbonyl complexes L/sub 2/Mo(CO)/sub 4/, L/sub 3/Mo(CO)/sub 3/ and L/sub 2/L'/sub 2/Mo(CO)/sub 2/ several new complex types with the C-C-twisted tetraalkyldithiooxamides (R/sub 4/dto) and the planar N,N'-dialkyldithiooxamide (R/sub 2/H/sub 2/dto) such as (R/sub 4/dto)Mo(CO)/sub 4/, (R/sub 2/H/sub 2/dto)Mo(CO)/sub 4/, (R/sub 2/R'/sub 2/dto)Mo(CO)/sub 3/(P(C/sub 6/H/sub 5/)/sub 3/), (R/sub 2/R'/sub 2/dto)Mo(CO)/sub 2/(PR/sub 3/)/sub 2/ are described and compared with complexes of a cyclic dithiooxamide and analogous complexes with thioamides R/sub 2/NC(S)R'. In Mo(CO)/sub 4/ complexes, dithiooxamides display a rather strong donor character and are thus similar to simple thioamides, but the blue colour of the R/sub 2/H/sub 2/dto complexes indicates already low-lying acceptor levels. When passing from the Mo(CO)/sub 4/ complexes via Mo(CO)/sub 3/(PR/sub 3/) complexes to the very electron rich Mo(CO)/sub 2/(PR/sub 3/)/sub 2/ complexes, the IR and electronic spectra indicate an unexpected and drastic change in ligand character. Dto ligands in the latter complex type turn out to be very strong acceptors, independent of the degree of N-alkylation. A conformational change, with twisted R/sub 2/N-C bonds and a planar S-C-C-S skeleton (as in the dithiolene complexes), can account for all the peculiarities of the (dto)-dicarbonylbis(phosphine) complexes as compared to the 'normal' thioamide complexes. Dithiooxamides can thus control the oxidation state of metals by a remote conformational change and possibly act as an electron reservoir in chemical reactions at the metal center.

  16. A Synthesized Model-Observation Approach to Constraining Gross Urban CO2 Fluxes Using 14CO2 and carbonyl sulfide

    Science.gov (United States)

    LaFranchi, B. W.; Campbell, J. E.; Cameron-Smith, P. J.; Bambha, R.; Michelsen, H. A.

    2013-12-01

    Urbanized regions are responsible for a disproportionately large percentage (30-40%) of global anthropogenic greenhouse gas (GHG) emissions, despite covering only 2% of the Earth's surface area [Satterthwaite, 2008]. As a result, policies enacted at the local level in these urban areas can, in aggregate, have a large global impact, both positive and negative. In order to address the scientific questions that are required to drive these policy decisions, methods are needed that resolve gross CO2 flux components from the net flux. Recent work suggests that the critical knowledge gaps in CO2 surface fluxes could be addressed through the combined analysis of atmospheric carbonyl sulfide (COS) and radiocarbon in atmospheric CO2 (14CO2) [e.g. Campbell et al., 2008; Graven et al., 2009]. The 14CO2 approach relies on mass balance assumptions about atmospheric CO2 and the large differences in 14CO2 abundance between fossil and natural sources of CO2 [Levin et al., 2003]. COS, meanwhile, is a potentially transformative tracer of photosynthesis because its variability in the atmosphere has been found to be influenced primarily by vegetative uptake, scaling linearly will gross primary production (GPP) [Kettle et al., 20027]. Taken together, these two observations provide constraints on two of the three main components of the CO2 budget at the urban scale: photosynthesis and fossil fuel emissions. The third component, respiration, can then be determined by difference if the net flux is known. Here we present a general overview of our synthesized model-observation approach for improving surface flux estimates of CO2 for the upwind fetch of a ~30m tower located in Livermore, CA, USA, a suburb (pop. ~80,000) at the eastern edge of the San Francisco Bay Area. Additionally, we will present initial results from a one week observational intensive, which includes continuous CO2, CH4, CO, SO2, NOx, and O3 observations in addition to measurements of 14CO2 and COS from air samples

  17. Determination of protein-carbonyls and ubiquitin-mediated proteolysis as biomarkers of oxidative-stress in bivalvia and anthozoa

    Energy Technology Data Exchange (ETDEWEB)

    Walker, Stephen Thomas

    2002-07-01

    This study describes the investigation of biomarkers of oxidative-stress in the bivalves Mytilus edulis and Dosinia lupinus, together with host and symbiont tissues of the scleractinian Anthozoa Agaricia agaricites. The biomarkers used were assay of total (via spectrophotometry) and individual (via Western blotting; Oxyblot kit) protein-carbonyls (PC=Os) and content of ubiquitin protein conjugates (UPC) via Western blotting (Bivalvia and Anthozoa) and immunohistochemistry (Anthozoa only). Additional assays for Bivalvia were Trolox equivalent antioxidant capacity (TEAC); and post {gamma}-irradiation survival rates. Experimental stressors for Bivalvia were increased seawater temperature, H{sub 2}O{sub 2} and {sup 60}Co {gamma}-radiation (latter two were used in vivo and in vitro). Comparisons of clean and polluted marine sites are included. Stressors used for Anthozoa were increased solar irradiation concomitant with elevated seawater temperature. Results and conclusions were as follows: individual samples showed considerable variation, pooling of samples improved consistency. Controls for both biomarkers had detectable background levels in each phylum, against which relatively small differences were assessed. In M. edulis, no measurable differences in PC=Os could be determined when elevated seawater temperature or dilute H{sub 2}O{sub 2} (<30% v/v) stressors were used, nor with between-site comparisons. Concentrated H{sub 2}O{sub 2} (30% v/v) produced a small difference. {sup 60}Co {gamma}-radiation produced clearer differences via Oxyblot and spectrophotometric assays. Comparison of four different tissues from the two bivalves found considerable species-specific and tissue-specific differences. Post-irradiation mortality between species was significantly different (<0.001), D. lupinus was more susceptible than M. edulis. TEAC values generally showed a decrease following irradiation (except for digestive gland). UPCs were clearly different between tissues and

  18. Probing the Carbonyl Functionality of a Petroleum Resin and Asphaltene through Oximation and Schiff Base Formation in Conjunction with N-15 NMR.

    Directory of Open Access Journals (Sweden)

    Kevin A Thorn

    Full Text Available Despite recent advances in spectroscopic techniques, there is uncertainty regarding the nature of the carbonyl groups in the asphaltene and resin fractions of crude oil, information necessary for an understanding of the physical properties and environmental fate of these materials. Carbonyl and hydroxyl group functionalities are not observed in natural abundance 13C nuclear magnetic resonance (NMR spectra of asphaltenes and resins and therefore require spin labeling techniques for detection. In this study, the carbonyl functionalities of the resin and asphaltene fractions from a light aliphatic crude oil that is the source of groundwater contamination at the long term USGS study site near Bemidji, Minnesota, have been examined through reaction with 15N-labeled hydroxylamine and aniline in conjunction with analysis by solid and liquid state 15N NMR. Ketone groups were revealed through 15N NMR detection of their oxime and Schiff base derivatives, and esters through their hydroxamic acid derivatives. Anilinohydroquinone adducts provided evidence for quinones. Some possible configurations of the ketone groups in the resin and asphaltene fractions can be inferred from a consideration of the likely reactions that lead to heterocyclic condensation products with aniline and to the Beckmann reaction products from the initially formed oximes. These include aromatic ketones and ketones adjacent to quaternary carbon centers, β-hydroxyketones, β-diketones, and β-ketoesters. In a solid state cross polarization/magic angle spinning (CP/MAS 15N NMR spectrum recorded on the underivatized asphaltene as a control, carbazole and pyrrole-like nitrogens were the major naturally abundant nitrogens detected.

  19. Human carbonyl reductase 1 participating in intestinal first-pass drug metabolism is inhibited by fatty acids and acyl-CoAs.

    Science.gov (United States)

    Hara, Akira; Endo, Satoshi; Matsunaga, Toshiyuki; El-Kabbani, Ossama; Miura, Takeshi; Nishinaka, Toru; Terada, Tomoyuki

    2017-08-15

    Human carbonyl reductase 1 (CBR1), a member of the short-chain dehydrogenase/reductase (SDR) superfamily, reduces a variety of carbonyl compounds including endogenous isatin, prostaglandin E2 and 4-oxo-2-nonenal. It is also a major non-cytochrome P450 enzyme in the phase I metabolism of carbonyl-containing drugs, and is highly expressed in the intestine. In this study, we found that long-chain fatty acids and their CoA ester derivatives inhibit CBR1. Among saturated fatty acids, myristic, palmitic and stearic acids were inhibitory, and stearic acid was the most potent (IC50 9µM). Unsaturated fatty acids (oleic, elaidic, γ-linolenic and docosahexaenoic acids) and acyl-CoAs (palmitoyl-, stearoyl- and oleoyl-CoAs) were more potent inhibitors (IC50 1.0-2.5µM), and showed high inhibitory selectivity to CBR1 over its isozyme CBR3 and other SDR superfamily enzymes (DCXR and DHRS4) with CBR activity. The inhibition by these fatty acids and acyl-CoAs was competitive with respect to the substrate, showing the Ki values of 0.49-1.2µM. Site-directed mutagenesis of the substrate-binding residues of CBR1 suggested that the interactions between the fatty acyl chain and the enzyme's Met141 and Trp229 are important for the inhibitory selectivity. We also examined CBR1 inhibition by oleic acid in cellular levels: The fatty acid effectively inhibited CBR1-mediated 4-oxo-2-nonenal metabolism in colon cancer DLD1 cells and increased sensitivity to doxorubicin in the drug-resistant gastric cancer MKN45 cells that highly express CBR1. The results suggest a possible new food-drug interaction through inhibition of CBR1-mediated intestinal first-pass drug metabolism by dietary fatty acids. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Probing the carbonyl functionality of a petroleum resin and asphaltene through oximation and schiff base formation in conjunction with N-15 NMR

    Science.gov (United States)

    Thorn, Kevin A.; Cox, Larry G.

    2015-01-01

    Despite recent advances in spectroscopic techniques, there is uncertainty regarding the nature of the carbonyl groups in the asphaltene and resin fractions of crude oil, information necessary for an understanding of the physical properties and environmental fate of these materials. Carbonyl and hydroxyl group functionalities are not observed in natural abundance 13C nuclear magnetic resonance (NMR) spectra of asphaltenes and resins and therefore require spin labeling techniques for detection. In this study, the carbonyl functionalities of the resin and asphaltene fractions from a light aliphatic crude oil that is the source of groundwater contamination at the long term USGS study site near Bemidji, Minnesota, have been examined through reaction with 15N-labeled hydroxylamine and aniline in conjunction with analysis by solid and liquid state 15N NMR. Ketone groups were revealed through 15N NMR detection of their oxime and Schiff base derivatives, and esters through their hydroxamic acid derivatives. Anilinohydroquinone adducts provided evidence for quinones. Some possible configurations of the ketone groups in the resin and asphaltene fractions can be inferred from a consideration of the likely reactions that lead to heterocyclic condensation products with aniline and to the Beckmann reaction products from the initially formed oximes. These include aromatic ketones and ketones adjacent to quaternary carbon centers, β-hydroxyketones, β-diketones, and β-ketoesters. In a solid state cross polarization/magic angle spinning (CP/MAS) 15N NMR spectrum recorded on the underivatized asphaltene as a control, carbazole and pyrrole-like nitrogens were the major naturally abundant nitrogens detected.

  1. Cell signaling promoting protein carbonylation does not cause sulfhydryl oxidation: Implications to the mechanism of redox signaling [version 1; referees: 1 approved, 2 approved with reservations

    Directory of Open Access Journals (Sweden)

    Yuichiro J. Suzuki

    2017-04-01

    Full Text Available Reactive oxygen species (ROS have been recognized as second messengers, however, targeting mechanisms for ROS in cell signaling have not been defined. While ROS oxidizing protein cysteine thiols has been the most popular proposed mechanism, our laboratory proposed that ligand/receptor-mediated cell signaling involves protein carbonylation. Peroxiredoxin-6 (Prx6 is one protein that is carbonylated at 10 min after the platelet-derived growth factor (PDGF stimulation of human pulmonary artery smooth muscle cells. In the present study, the SulfoBiotics Protein Redox State Monitoring Kit Plus (Dojindo Molecular Technologies was used to test if cysteine residues of Prx6 are oxidized in response to the PDGF stimulation. Human Prx6 has a molecular weight of 25 kDa and contains two cysteine residues. The Dojindo system adds the 15 kDa Protein-SHifter if these cysteine residues are reduced in the cells. Results showed that, in untreated cells, the Prx6 molecule predominantly exhibited the 55 kDa band, indicating that both cysteine residues are reduced in the cells. Treatment of cells with 1 mM H2O2 caused the disappearance of the 55 kDa band and the appearance of a 40 kDa band, suggesting that the high concentration of H2O2 oxidized one of the two cysteine residues in the Prx6 molecule. By contrast, PDGF stimulation had no effects on the thiol status of the Prx6 molecule. We concluded that protein carbonylation is a more sensitive target of ROS during ligand/receptor-mediated cell signaling than sulfhydryl oxidation.

  2. Direct Analysis of Free and Sulfite-Bound Carbonyl Compounds in Wine by Two-Dimensional Quantitative Proton and Carbon Nuclear Magnetic Resonance Spectroscopy.

    Science.gov (United States)

    Nikolantonaki, Maria; Magiatis, Prokopios; Waterhouse, Andrew L

    2015-11-03

    Recent developments that have accelerated 2D NMR methods and improved quantitation have made these methods accessible analytical procedures, and the large signal dispersion allows for the analysis of complex samples. Few natural samples are as complex as wine, so the application to challenges in wine analysis look promising. The analysis of carbonyl compounds in wine, key oxidation products, is complicated by a multitude of kinetically reversible adducts, such as acetals and sulfonates, so that sample preparation steps can generate complex interferences. These challenges could be overcome if the compounds could be quantified in situ. Here, two-dimensional ((1)H-(1)H) homonuclear and heteronuclear ((13)C-(1)H) single quantum correlations (correlation spectroscopy, COSY, and heteronuclear single quantum coherence, HSQC) nuclear magnetic resonance spectra of undiluted wine samples were observed at natural abundance. These techniques achieve simultaneous direct identification and quantitation of acetaldehyde, pyruvic acid, acetoin, methylglyoxal, and α-ketoglutaric acid in wine with only a small addition of D2O. It was also possible to observe and sometimes quantify the sulfite, hydrate, and acetal forms of the carbonyl compounds. The accuracy of the method was tested in wine samples by spiking with a mixture of all analytes at different concentrations. The method was applied to 15 wine samples of various vintages and grape varieties. The application of this method could provide a powerful tool to better understand the development, evolution, and perception of wine oxidation and insight into the impact of these sulfite bound carbonyls on antimicrobial and antioxidant action by SO2.

  3. Ruthenium(II carbonyl compounds with the 4′-chloro-2,2′:6′,2′′-terpyridine ligand

    Directory of Open Access Journals (Sweden)

    Rajendhraprasad Tatikonda

    2017-04-01

    Full Text Available Two ruthenium carbonyl complexes with the 4′-chloro-2,2′:6′,2′′-terpyridine ligand (tpy-Cl, C15H10ClN3, i.e. [RuCl(tpy-Cl(CO2][RuCl3(CO3] (I [systematic name: cis-dicarbonylchlorido(4′-chloro-2,2′:6′,2′′-terpyridine-κ3Nruthenium(II fac-tricarbonyltrichloridoruthenate(II], and [RuCl2(tpy-Cl(CO2] (II [cis-dicarbonyl-trans-dichlorido(4′-chloro-2,2′:6′,2′′-terpyridine-κ2N1,N1′ruthenium(II], were synthesized and characterized by single-crystal X-ray diffraction. The RuII atoms in both centrosymmetric structures (I and (II display similar, slightly distorted octahedral coordination spheres. The coordination sphere in the complex cation in compound (I is defined by three N atoms of the tridentate tpy-Cl ligand, two carbonyl carbon atoms and one chlorido ligand; the charge is balanced by an octahedral [Ru(CO3Cl3]− counter-anion. In the neutral compound (II, the tpy-Cl ligand coordinates to the metal only through two of its N atoms. The coordination sphere of the RuII atom is completed by two carbonyl and two chlorido ligands. In the crystal structures of both (I and (II, weak C—H...Cl interactions are observed.

  4. Higher Efficiency HVAC Motors

    Energy Technology Data Exchange (ETDEWEB)

    Flynn, Charles Joseph

    2018-02-13

    failure prone capacitors from the power stage. Q-Sync’s simpler electronics also result in higher efficiency because it eliminates the power required by the PCB to perform the obviated power conversions and PWM processes after line synchronous operating speed is reached in the first 5 seconds of operation, after which the PWM circuits drop out and a much less energy intensive “pass through” circuit takes over, allowing the grid-supplied AC power to sustain the motor’s ongoing operation.

  5. Correlation of volatile carbonyl yields emitted by e-cigarettes with the temperature of the heating coil and the perceived sensorial quality of the generated vapours.

    Science.gov (United States)

    Geiss, Otmar; Bianchi, Ivana; Barrero-Moreno, Josefa

    2016-05-01

    E-liquids generally contain four main components: nicotine, flavours, water and carrier liquids. The carrier liquid dissolves flavours and nicotine and vaporises at a certain temperature on the atomizer of the e-cigarette. Propylene glycol and glycerol, the principal carriers used in e-liquids, undergo decomposition in contact with the atomizer heating-coil forming volatile carbonyls. Some of these, such as formaldehyde, acetaldehyde and acrolein, are of concern due to their adverse impact on human health when inhaled at sufficient concentrations. The aim of this study was to correlate the yield of volatile carbonyls emitted by e-cigarettes with the temperature of the heating coil. For this purpose, a popular commercial e-liquid was machine-vaped on a third generation e-cigarette which allowed the variation of the output wattage (5-25W) and therefore the heat generated on the atomizer heating-coil. The temperature of the heating-coil was determined by infrared thermography and the vapour generated at each temperature underwent subjective sensorial quality evaluation by an experienced vaper. A steep increase in the generated carbonyls was observed when applying a battery-output of at least 15W corresponding to 200-250°C on the heating coil. However, when considering concentrations in each inhaled puff, the short-term indoor air guideline value for formaldehyde was already exceeded at the lowest wattage of 5W, which is the wattage applied in most 2nd generation e-cigarettes. Concentrations of acetaldehyde in each puff were several times below the short-term irritation threshold value for humans. Acrolein was only detected from 20W upwards. The negative sensorial quality evaluation by the volunteering vaper of the vapour generated at 20W demonstrated the unlikelihood that such a wattage would be realistically set by a vaper. This study highlights the importance to develop standardised testing methods for the assessment of carbonyl-emissions and emissions of other

  6. RNA-Seq approach for genetic improvement of meat quality in pig and evolutionary insight into the substrate specificity of animal carbonyl reductases.

    Science.gov (United States)

    Jung, Won Yong; Kwon, Seul Gi; Son, Minky; Cho, Eun Seok; Lee, Yuno; Kim, Jae Hwan; Kim, Byeong-Woo; Park, Da Hye; Hwang, Jung Hye; Kim, Tae Wan; Park, Hwa Choon; Park, Beom Young; Choi, Jong-Soon; Cho, Kwang Keun; Chung, Ki Hwa; Song, Young Min; Kim, Il Suk; Jin, Sang Keun; Kim, Doo Hwan; Lee, Seung-Won; Lee, Keun Woo; Bang, Woo Young; Kim, Chul Wook

    2012-01-01

    Changes in meat quality traits are strongly associated with alterations in postmortem metabolism which depend on genetic variations, especially nonsynonymous single nucleotide variations (nsSNVs) having critical effects on protein structure and function. To selectively identify metabolism-related nsSNVs, next-generation transcriptome sequencing (RNA-Seq) was carried out using RNAs from porcine liver, which contains a diverse range of metabolic enzymes. The multiplex SNV genotyping analysis showed that various metabolism-related genes had different nsSNV alleles. Moreover, many nsSNVs were significantly associated with multiple meat quality traits. Particularly, ch7:g.22112616A>G SNV was identified to create a single amino acid change (Thr/Ala) at the 145th residue of H1.3-like protein, very close to the putative 147th threonine phosphorylation site, suggesting that the nsSNV may affect multiple meat quality traits by affecting the epigenetic regulation of postmortem metabolism-related gene expression. Besides, one nonsynonymous variation, probably generated by gene duplication, led to a stop signal in porcine testicular carbonyl reductase (PTCR), resulting in a C-terminal (E281-A288) deletion. Molecular docking and energy minimization calculations indicated that the binding affinity of wild-type PTCR to 5α-DHT, a C(21)-steroid, was superior to that of C-terminal-deleted PTCR or human carbonyl reductase, which was very consistent with experimental data, reported previously. Furthermore, P284 was identified as an important residue mediating the specific interaction between PTCR and 5α-DHT, and phylogenetic analysis showed that P284 is an evolutionarily conserved residue among animal carbonyl reductases, which suggests that the C-terminal tails of these reductases may have evolved under evolutionary pressure to increase the substrate specificity for C(21)-steroids and facilitate metabolic adaptation. Altogether, our RNA-Seq revealed that selective nsSNVs were

  7. Biogenic emissions and ambient concentrations of hydrocarbons, carbonyl compounds and organic acids from ponderosa pine and cottonwood trees at rural and forested sites in Central New Mexico

    Science.gov (United States)

    Villanueva-Fierro, Ignacio; Popp, Carl J.; Martin, Randal S.

    Direct emission rates of carbonyl compounds, carboxylic acids and hydrocarbons from Populus fremontil (cottonwood) and Pinus ponderosa (ponderosa pine) trees were studied during the summer of 1997. Ambient air concentrations of these compounds in the vicinity of the sampled trees were also identified and quantified. Study sites were Socorro, NM and Langmuir Laboratory, NM a rural and forested, high mountain site, respectively, located in Central New Mexico. A dynamic branch enclosure method was used to perform the sampling of tree emissions, that are given at standard atmospheric temperature of 303 K, and 1000 μmol m -2 s -1 PAR. Average emission rates of acetic and formic acid, respectively, from cottonwood were 470±540 and 310±300 ng g -1 h -1 and from ponderosa pine were 170±180 and 210±210 ng g -1 h -1. Formaldehyde and acetaldehyde average emission rates, respectively, from ponderosa pine were 500±400 and 250±190 ng g -1 h -1, and from cottonwood were 4070±3570 and 1190±1360 ng g -1 h -1. Cottonwood had an average isoprene emission rate of 9050±10700 ng g -1 h -1, while ponderosa pine had emission rates of α-pinene and β-pinene of 450±1100 and 520±1050 ng g -1 h -1, respectively. Total mass emissions of carbon compounds measured from cottonwood were four times larger than from ponderosa pine. Seasonal, diurnal, and temperature dependence of concentrations in ambient air and emission rates from trees are also discussed. Average ambient air concentrations of acetic and formic acid, respectively, were 2.7±3.8 and 0.7±0.9 ppbv for the rural site, and 1.7±2.0 and 0.6±0.5 ppbv for the mountain site. The average range of carbonyl compound concentrations in ambient air was from 0.3 to 3.4 ppbv for various carbonyl compounds with about 60% of the ambient carbonyls consisting of formaldehyde, acetaldehyde and acetone. Isoprene and monoterpene concentrations in ambient air were usually below the detection limit.

  8. Hydroformylation of olefins and reductive carbonylation of aryl halides with syngas formed ex situ from dehydrogenative decarbonylation of hexane-1,6-diol

    DEFF Research Database (Denmark)

    Christensen, Stig Holden; Olsen, Esben Paul Krogh; Rosenbaum, Jascha

    2014-01-01

    and then consumed in the other chamber in either a rhodium-catalysed hydroformylation of olefins or a palladium-catalysed reductive carbonylation of aryl halides. Hexane-1,6-diol was found to be the optimum alcohol for both reactions where moderate to excellent yields were obtained of the product aldehydes......A variety of primary alcohols have been investigated as convenient substrates for the ex situ delivery of carbon monoxide and molecular hydrogen in a two-chamber reactor. The gaseous mixture is liberated in one chamber by an iridium-catalysed dehydrogenative decarbonylation of the alcohol...

  9. Testing the nature of reaction coordinate describing interaction of H2 with carbonyl carbon, activated by Lewis acid complexation, and the Lewis basic solvent: A Born-Oppenheimer molecular dynamics study with explicit solvent

    Science.gov (United States)

    Heshmat, Mojgan; Privalov, Timofei

    2017-09-01

    Using Born-Oppenheimer molecular dynamics (BOMD), we explore the nature of interactions between H2 and the activated carbonyl carbon, C(carbonyl), of the acetone-B(C6F5)3 adduct surrounded by an explicit solvent (1,4-dioxane). BOMD simulations at finite (non-zero) temperature with an explicit solvent produced long-lasting instances of significant vibrational perturbation of the H—H bond and H2-polarization at C(carbonyl). As far as the characteristics of H2 are concerned, the dynamical transient state approximates the transition-state of the heterolytic H2-cleavage. The culprit is the concerted interactions of H2 with C(carbonyl) and a number of Lewis basic solvent molecules—i.e., the concerted C(carbonyl)⋯H2⋯solvent interactions. On one hand, the results presented herein complement the mechanistic insight gained from our recent transition-state calculations, reported separately from this article. But on the other hand, we now indicate that an idea of the sufficiency of just one simple reaction coordinate in solution-phase reactions can be too simplistic and misleading. This article goes in the footsteps of the rapidly strengthening approach of investigating molecular interactions in large molecular systems via "computational experimentation" employing, primarily, ab initio molecular dynamics describing reactants-interaction without constraints of the preordained reaction coordinate and/or foreknowledge of the sampling order parameters.

  10. Defense Against Reactive Carbonyl Species Involves at Least Three Subcellular Compartments where Individual Components of the System Respond to Cellular Sugar Status.

    Science.gov (United States)

    Schmitz, Jessica; Dittmar, Isabell C; Brockmann, Jörn D; Schmidt, Marc; Hüdig, Meike; Rossoni, Alessandro W; Maurino, Veronica G

    2017-11-17

    Methylglyoxal (MGO) and glyoxal (GO) are toxic reactive carbonyl species generated as by-products of glycolysis. The pre-emption pathway for detoxification of these products, the glyoxalase (GLX) system, involves two consecutive reactions catalyzed by GLXI and GLXII. In Arabidopsis thaliana, the GLX system is encoded by three homologs of GLXI and three homologs of GLXII, from which several predicted GLXI and GLXII isoforms can be derived through alternative splicing. We identified the physiologically relevant splice forms using sequencing data and demonstrated that the resulting isoforms have different subcellular localizations. All three GLXI homologs are functional in vivo, as they complemented a yeast GLXI loss-of-function mutant. Efficient MGO and GO detoxification can be controlled by a switch in metal cofactor usage. MGO formation is closely connected to the flux through glycolysis and through the Calvin Benson cycle; accordingly, expression analysis indicated that GLXI is transcriptionally regulated by endogenous sugar levels. Analyses of Arabidopsis loss-of-function lines revealed that the elimination of toxic reactive carbonyl species during germination and seedling establishment depends on the activity of the cytosolic GLXI;3 isoform. The Arabidopsis GLX system involves the cytosol, chloroplasts, and mitochondria, which harbor individual components that might be utilized at specific developmental stages and respond differentially to cellular sugar status. © 2017 American Society of Plant Biologists. All rights reserved.

  11. Relationship between thiol, tyrosine nitration and carbonyl formation as biomarkers of oxidative stress and changes of hemostatic function of plasma from breast cancer patients before surgery.

    Science.gov (United States)

    Kedzierska, Magdalena; Olas, Beata; Wachowicz, Barbara; Jeziorski, Arkadiusz; Piekarski, Janusz

    2012-02-01

    In breast cancer patients dysregulation of reactive oxygen species metabolism, as detected by various indicators in plasma or various blood cells, including red blood cells and blood platelets, is observed. The aim of our study was to explain the effect of oxidative/nitrative stress on hemostatic activity of plasma from breast cancer patients. Different methods were used to analyze oxidative/nitrative stress (carbonyl groups and 3-nitrotyrosine levels - ELISA and C-ELISA method, respectively and free thiol groups was estimated with 5,5'-dithio-bis(2-nitro-benzoic acid)). We also measured total antioxidant status (TAS) in plasma. Our results showed the correlation between the oxidative stress and changes of hemostasis in breast cancer patients; the correlation between the increased amount of carbonylated or nitrated plasma proteins and fibrin polymerization or lysis in plasma isolated from invasive breast cancer patients. We also observed that the relationship between TAS and fibrin polymerization or lysis in plasma from invasive breast cancer exists. Considering the data presented in this study, we suggest that the oxidative/nitrative stress in breast cancer patients may induce the changes of hemostasis in these patients. Published by Elsevier Inc.

  12. Synthesis and assessment of CO-release capacity of manganese carbonyl complexes derived from rigid α-diimine ligands of varied complexity.

    Science.gov (United States)

    Jimenez, Jorge; Chakraborty, Indranil; Mascharak, Pradip K

    2015-10-01

    Four manganese carbonyl complexes of the type [MnBr(CO)3(NˆN)] (NˆN = α-diimine ligands) namely [MnBr(CO)3(bpy)] (1), [MnBr(CO)3(phen)] (2), [MnBr(CO)3(dafo)] (3) and [MnBr(CO)3(pyzphen)] (4) (where bpy = bipyridine, phen = 1,10-phenanthroline, dafo = 4,5-diazafluoren-9-one and pyzphen = pyrazino[2,3-f][1,10]-phenanthroline) have been synthesized and structurally characterized. These four complexes containing the fac-[Mn(CO)3] motif release CO upon illumination with low power visible and UV light. The CO release rates and the absorption maxima of the complexes are however very similar despite systematic increase in structural complexity in the rigid α-diimine ligand frames. This is quite in contrary to manganese carbonyl complexes derived from α-diimine ligands in which at least one of the imine functions is not part of the rigid ring systems. Results of this study will provide help in the future design of ligand frames suitable for the syntheses of photoCORMs to deliver CO to biological targets under the control of light.

  13. FTIR investigation of solvent-induced carbonyl band shifts of 17β-hydroxy-17α-picolyl-androst-4-en-3-one

    Directory of Open Access Journals (Sweden)

    Jović Branislav D.

    2014-01-01

    Full Text Available Polar functional groups in the A- and D-ring (positions C-3 and C-17 are common for the most of natural and synthetic steroid hormones. It is assumed that these pharmacophoric groups are involved in the strong hydrogen bonding interactions with the respective steroid receptors. Infrared spectroscopy studies of 17β-hydroxy-17α-picolyl-androst-4-en-3-one were undertaken in 13 organic solvents to investigate solvent-solute interactions. The wavenumbers of carbonyl stretching vibration n(C=O in different solvents were correlated with the solvent acceptor number (AN, the linear solvation energy relationships (LSER and extended KBM-Buckingham equation. Significant correlation of the position of the carbonile band with empirical parameters was obtained in alcoholic and non-alcoholic solvents. Based on the obtained results it was concluded that the hydrogen bonding formation and the dipolarity/polarizability properties are important factors that determine position of carbonyl group band in the IR spectra, and are also important for the interactions in biological systems. [Projekat Ministarstva nauke Republike Srbije, br. 172013 i br. 172021

  14. Directed Evolution of Carbonyl Reductase from Rhodosporidium toruloides and Its Application in Stereoselective Synthesis of tert-Butyl (3R,5S)-6-Chloro-3,5-dihydroxyhexanoate.

    Science.gov (United States)

    Liu, Zhi-Qiang; Wu, Lin; Zhang, Xiao-Jian; Xue, Ya-Ping; Zheng, Yu-Guo

    2017-05-10

    tert-Butyl (3R,5S)-6-chloro-3,5-dihydroxyhexanoate ((3R,5S)-CDHH) is a key intermediate of atorvastatin and rosuvastatin synthesis. Carbonyl reductase RtSCR9 from Rhodosporidium toruloides exhibited excellent activity toward tert-butyl (S)-6-chloro-5-hydroxy-3-oxohexanoate ((S)-CHOH). For the activity of RtSCR9 to be improved, random mutagenesis and site-saturation mutagenesis were performed. Three positive mutants were obtained (mut-Gln95Asp, mut-Ile144Lys, and mut-Phe156Gln). These mutants exhibited 1.94-, 3.03-, and 1.61-fold and 1.93-, 3.15-, and 1.97-fold improvement in the specific activity and kcat/Km, respectively. Asymmetric reduction of (S)-CHOH by mut-Ile144Lys coupled with glucose dehydrogenase was conducted. The yield and enantiomeric excess of (3R,5S)-CDHH reached 98 and 99%, respectively, after 8 h bioconversion in a single batch reaction with 1 M (S)-CHOH, and the space-time yield reached 542.83 mmol L-1 h-1 g-1 wet cell weight. This study presents a new carbonyl reductase for efficient synthesis of (3R,5S)-CDHH.

  15. Effect of resin content and substrate on the emission of BTEX and carbonyls from low-VOC water-based wall paint.

    Science.gov (United States)

    Zhao, Ping; Cheng, Yu-Hsiang; Lin, Chi-Chi; Cheng, Yu-Lin

    2016-02-01

    The primary aim of this work is to explore the effect of resin content and the effect of substrate on the emission of benzene, toluene, ethylbenzene, and xylene (BTEX) and carbonyls from low-VOC water-based wall paint. Four low-volatile organic compound (VOC) paints include paints A (20% acrylic), B (30% acrylic), C (20% polyvinyl acetate), and D (30% polyvinyl acetate) were painted on stainless steel specimen for the study of resin effect. Green calcium silicate, green cement, and stainless steel were painted with paints A and C for the study of substrate effect. Concentrations of the VOCs in the chamber decreased with the elapsed time. Both resin type and resin quantity in paint had effects on VOC emissions. Paints with acrylic resin emitted less BTEX and carbonyls than paints with polyvinyl acetate resin. However, the effects of resin quantity varied with VOCs. Porous substrates were observed to interact more strongly with paints than inert substrates. Both green calcium silicate and green cement substrates have strong power of adsorption of VOCs from wall paints, namely toluene, formaldehyde, acetaldehyde, 2-butanone, methacrolein, butyraldehyde, and benzaldehyde. Some compounds like toluene, formaldehyde, and butyaldehyde were desorbed very slowly from green calcium silicate and green cement substrates.

  16. Laser photolysis studies of ω-bond dissociation in aromatic carbonyls with a C-C triple bond stimulated by triplet sensitization.

    Science.gov (United States)

    Yamaji, Minoru; Horimoto, Ami; Marciniak, Bronislaw

    2017-07-14

    We have prepared three types of carbonyl compounds, benzoylethynylmethyl phenyl sulfide (2@SPh), (p-benzoyl)phenylethynylmethyl phenyl sulfide (3@SPh) and p-(benzoylethynyl)benzyl phenyl sulfide (4@SPh) with benzoyl and phenylthiylmethyl groups, which are interconnected with a C-C triple bond and a phenyl ring. Laser flash photolysis of 3@SPh and 4@SPh in acetonitrile provided the transient absorption spectra of the corresponding triplet states where no chemical reactions were recognized. Upon laser flash photolysis of 2@SPh, the absorption band due to the phenylthiyl radical (PTR) was obtained, indicating that the C-S bond cleaved in the excited state. Triplet sensitization of these carbonyl compounds using acetone and xanthone was conducted using laser photolysis techniques. The formation of triplet 3@SPh was seen in the transient absorption, whereas the PTR formation was observed for 2@SPh and 4@SPh, indicating that the triplet states were reactive for the C-S bond dissociation. The C-S bond dissociation mechanism for 4@SPh upon triplet sensitization is discussed in comparison with those for 2@SPh and 3@SPh.

  17. Iron-Carbonyl-Catalyzed Redox-Neutral [4+2] Annulation of N-H Imines and Internal Alkynes by C-H Bond Activation.

    Science.gov (United States)

    Jia, Teng; Zhao, Chongyang; He, Ruoyu; Chen, Hui; Wang, Congyang

    2016-04-18

    Stoichiometric C-H bond activation of arenes mediated by iron carbonyls was reported by Pauson as early as in 1965, yet the catalytic C-H transformations have not been developed. Herein, an iron-catalyzed annulation of N-H imines and internal alkynes to furnish cis-3,4-dihydroisoquinolines is described, and represents the first iron-carbonyl-catalyzed C-H activation reaction of arenes. Remarkablely, this is also the first redox-neutral [4+2] annulation of imines and alkynes proceeding by C-H activation. The reaction also features only cis stereoselectivity and excellent atom economy as neither base, nor external ligand, nor additive is required. Experimental and theoretical studies reveal an oxidative addition mechanism for C-H bond activation to afford a dinuclear ferracycle and a synergetic diiron-promoted H-transfer to the alkyne as the turnover-determining step. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Short-term supplementation with acetyl-L-carnitine and lipoic acid alters plasma protein carbonyl levels but does not improve cognition in aged beagles

    Science.gov (United States)

    Christie, Lori-Ann; Opii, Wycliffe O.; Head, Elizabeth; Araujo, Joseph A.; De Rivera, Christina; Milgram, Norton W.; Cotman, Carl W.

    2009-01-01

    Previous work has shown that a diet enriched with antioxidants and mitochondrial co-factors improves cognition in aged dogs, which was accompanied by a reduction oxidative damage in the brain. The objective of the present study was to assess the effects of supplementation with mitochondrial co-factors on cognition and plasma protein carbonyl levels in aged dogs. Specifically, we aimed to test whether the individual or combined action of lipoic acid (LA) and acetyl-L-carnitine (ALCAR) could account for the beneficial effects of the enriched diet that contained both plus antioxidants. Dogs were given LA or ALCAR, alone and then in combination and cognition was assessed using a spatial learning task and two discrimination and reversal paradigms. Dogs receiving the ALCAR supplement showed an increase in protein carbonyl levels that was associated with increased error scores on the spatial task, and which was reduced upon additional supplementation with LA. We did not observe significant positive effects on cognition. The present findings suggest that short-term supplementation with LA and ALCAR is insufficient to improve cognition in aged dogs, and that the beneficial effects of the full spectrum diet arose from either the cellular antioxidants alone or their interaction with LA and ALCAR. PMID:19735717

  19. Sources and sinks of carbonyl sulfide in a mountain grassland and relationships to the carbon dioxide exchange

    Science.gov (United States)

    Spielmann, Felix M.; Kitz, Florian; Hammerle, Albin; Gerdel, Katharina; Wohlfahrt, Georg

    2016-04-01

    The trace gas carbonyl sulfide (COS) has been proposed as a tracer for canopy gross primary production (GPP), canopy transpiration and stomatal conductance of plant canopies in the last few years. COS enters the plant leaf through the stomata and diffuses through the intercellular space, the cell wall, the plasma membrane and the cytosol like CO2. It is then catalyzed by the enzyme carbonic anhydrase (CA) in a one-way reaction to H2S and CO2. This one-way flux into the leaf makes COS a promising tracer for the GPP. However there is growing evidence, that plant leaves aren't the only contributors to the ecosystem flux of COS. Therefor the COS uptake of soil microorganisms also containing CA and abiotic COS production might have to be accounted for when using COS as a tracer at the ecosystem scale. The overarching objective of this study was to quantify the relationship between the ecosystem-scale exchange of COS, CO2 and H2O and thus to test for the potential of COS to be used as a tracer for the plant canopy CO2 and H2O exchange. More specifically we aimed at quantifying the contribution of the soil to the ecosystem-scale COS exchange in order to understand complications that may arise due to a non-negligible soil COS exchange. In May 2015 we set up our quantum cascade laser (QCL) (Aerodyne Research Inc., MA, USA) at a temperate mountain grassland in Stubai Valley close to the village of Neustift, Austria. Our site lies at the valley bottom and is an intensively managed mountain grassland, which is cut 3-4 times a year. With the QCL we were able to measure concurrently the concentrations of COS, CO2, H2O (and CO) at a frequency of 10 Hz with minimal noise. This allowed us to conduct ecosystem-scale eddy covariance measurements. The eddy covariance flux measurements revealed that the COS uptake continues at night, which we confirmed was not caused by soil microorganisms, as the soil exchange was close to neutral during nighttime. Instead, the nocturnal COS uptake

  20. Internationalization of Chinese Higher Education

    Science.gov (United States)

    Chen, Linhan; Huang, Danyan

    2013-01-01

    This paper probes into the development of internationalization of higher education in China from ancient times to modern times, including the emergence of international connections in Chinese higher education and the subsequent development of such connections, the further development of internationalization of Chinese higher education, and the…