Cooperation between Magnesium and Metabolite Controls Collapse of the SAM-I Riboswitch.

Science.gov (United States)

Roy, Susmita; Onuchic, José N; Sanbonmatsu, Karissa Y

2017-07-25

The S-adenosylmethionine (SAM)-I riboswitch is a noncoding RNA that regulates the transcription termination process in response to metabolite (SAM) binding. The aptamer portion of the riboswitch may adopt an open or closed state depending on the presence of metabolite. Although the transition between the open and closed states is critical for the switching process, its atomistic details are not well understood. Using atomistic simulations, we calculate the effect of SAM and magnesium ions on the folding free energy landscape of the SAM-I riboswitch. These molecular simulation results are consistent with our previous wetlab experiments and aid in interpreting the SHAPE probing measurements. Here, molecular dynamics simulations explicitly identify target RNA motifs sensitive to magnesium ions and SAM. In the simulations, we observe that, whereas the metabolite mostly stabilizes the P1 and P3 helices, magnesium serves an important role in stabilizing a pseudoknot interaction between the P2 and P4 helices, even at high metabolite concentrations. The pseudoknot stabilization by magnesium, in combination with P1 stabilization by SAM, explains the requirement of both SAM and magnesium to form the fully collapsed metabolite-bound closed state of the SAM-I riboswitch. In the absence of SAM, frequent open-to-closed conformational transitions of the pseudoknot occur, akin to breathing. These pseudoknot fluctuations disrupt the binding site by facilitating fluctuations in the 5'-end of helix P1. Magnesium biases the landscape toward a collapsed state (preorganization) by coordinating pseudoknot and 5'-P1 fluctuations. The cooperation between SAM and magnesium in stabilizing important tertiary interactions elucidates their functional significance in transcription regulation. Published by Elsevier Inc.

Anomalous length dependence of conductance of aromatic nanoribbons with amine anchoring groups

KAUST Repository

Bilić, Ante

2012-09-06

Two sets of aromatic nanoribbons, based around a common hexagonal scaffolding, with single and dual terminal amine groups have been considered as potential molecular wires in a junction formed by gold leads. Charge transport through the two-terminal device has been modeled using density functional theory (with and without self-interaction correction) and the nonequilibrium Green\\'s function method. The effects of wire length, multiple terminal contacts, and pathways across the junction have been investigated. For nanoribbons with the oligopyrene motif and conventional single amine terminal groups, an increase in the wire length causes an exponential drop in the conductance. In contrast, for the nanoribbons with the oligoperylene motif and dual amine anchoring groups the predicted conductance rises with the wire length over the whole range of investigated lengths. Only when the effects of self-interaction correction are taken into account, the conductance of the oligoperylene ribbons exhibits saturation for longer members of the series. The oligoperylene nanoribbons, with dual amine groups at both terminals, show the potential to fully harness the highly conjugated system of π molecular orbitals across the junction. © 2012 American Physical Society.

Click functionalization of phenyl-capped bithiophene on azide-terminated self-assembled monolayers

International Nuclear Information System (INIS)

Zheng, Yijun; Cui, Jiaxi; Ikeda, Taichi

2015-01-01

Graphical abstract: - Highlights: • Electrochemically-active self-assembled monolayers with phenyl-capped bithiophene were prepared. • Post-functionalization method based on click chemistry solved the solubility issue of phenyl-capped thiophene alkanethiol. • The capture and release of the counter anions during the redox reaction were detectable by E-QCM. - Abstract: We immobilized tetra(ethylene glycol)-substituted phenyl-capped bithiophene with alkyne terminals (Ph2TPh-alkyne) on azide-terminated self-assembled monolayers (N 3 -SAMs) by Cu-catalyzed azide-alkyne cycloaddition reaction. Ph2TPh-functionalized SAMs on a gold substrate showed reversible electrochemical response. The surface densities of the azide groups in N 3 -SAMs and Ph2TPh units in Ph2TPh-functionalized SAMs were estimated to be 7.3 ± 0.3 × 10 −10 mol cm −2 and 4.6 ± 0.3 × 10 −10 mol cm −2 , respectively, by quartz crystal microbalance (QCM). Most of Ph2TPh-alkynes are considered to be anchored on N 3 -SAMs via both terminal groups. Ph2TPh-functionalized SAMs exhibited reversible redox peaks in cyclic voltammetry (CV). In redox reaction, reversible capture and release of the counter anion could be monitored by electrochemical QCM (E-QCM).

Click functionalization of phenyl-capped bithiophene on azide-terminated self-assembled monolayers

Energy Technology Data Exchange (ETDEWEB)

Zheng, Yijun; Cui, Jiaxi [Max Planck Institute for Polymer Research (MPIP), Ackermannweg 10, Mainz 55128 (Germany); Ikeda, Taichi, E-mail: IKEDA.Taichi@nims.go.jp [Max Planck Institute for Polymer Research (MPIP), Ackermannweg 10, Mainz 55128 (Germany); Polymer Materials Unit, National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba 305-0044 (Japan)

2015-11-15

Graphical abstract: - Highlights: • Electrochemically-active self-assembled monolayers with phenyl-capped bithiophene were prepared. • Post-functionalization method based on click chemistry solved the solubility issue of phenyl-capped thiophene alkanethiol. • The capture and release of the counter anions during the redox reaction were detectable by E-QCM. - Abstract: We immobilized tetra(ethylene glycol)-substituted phenyl-capped bithiophene with alkyne terminals (Ph2TPh-alkyne) on azide-terminated self-assembled monolayers (N{sub 3}-SAMs) by Cu-catalyzed azide-alkyne cycloaddition reaction. Ph2TPh-functionalized SAMs on a gold substrate showed reversible electrochemical response. The surface densities of the azide groups in N{sub 3}-SAMs and Ph2TPh units in Ph2TPh-functionalized SAMs were estimated to be 7.3 ± 0.3 × 10{sup −10} mol cm{sup −2} and 4.6 ± 0.3 × 10{sup −10} mol cm{sup −2}, respectively, by quartz crystal microbalance (QCM). Most of Ph2TPh-alkynes are considered to be anchored on N{sub 3}-SAMs via both terminal groups. Ph2TPh-functionalized SAMs exhibited reversible redox peaks in cyclic voltammetry (CV). In redox reaction, reversible capture and release of the counter anion could be monitored by electrochemical QCM (E-QCM).

Preparation and reactivity of carboxylic acid-terminated boron-doped diamond electrodes

International Nuclear Information System (INIS)

Niedziolka-Joensson, Joanna; Boland, Susan; Leech, Donal; Boukherroub, Rabah; Szunerits, Sabine

2010-01-01

The paper reports on the formation of carboxy-terminated boron-doped diamond (BDD) electrodes. The carboxylic acid termination was prepared in a controlled way by reacting photochemically oxidized BDD with succinic anhydride. The resulting interface was readily employed for the linking of an amine-terminated ligand such as an osmium complex bearing an amine terminal group. The interfaces were characterized using X-ray photoelectron spectroscopy (XPS) and cyclic voltammetry (CV). Contact angle measurements were used to follow the changes in surface wetting properties due to surface functionalization. The chemical reactivity of the carboxyl-terminated BDD was investigated by covalent coupling of the acid groups to an amine-terminated osmium complex.

Nickel Ligation of the N-Terminal Amine of HypA Is Required for Urease Maturation in Helicobacter pylori.

Science.gov (United States)

Hu, Heidi Q; Johnson, Ryan C; Merrell, D Scott; Maroney, Michael J

2017-02-28

The human pathogen Helicobacter pylori requires nickel for colonization of the acidic environment of the stomach. HypA, a Ni metallochaperone that is typically associated with hydrogenase maturation, is also required for urease maturation and acid survival of H. pylori. There are two proposed Ni site structures for HypA; one is a paramagnetic six-coordinate site characterized by X-ray absorption spectroscopy (XAS) in unmodified HypA, while another is a diamagnetic four-coordinate planar site characterized by solution nuclear magnetic resonance in an N-terminally modified HypA construct. To determine the role of the N-terminal amine in Ni binding of HypA, an N-terminal extension variant, L2*-HypA, in which a leucine residue was inserted into the second position of the amino acid sequence in the proposed Ni-binding motif, was characterized in vitro and in vivo. Structural characterization of the Ni site using XAS showed a coordination change from six-coordinate in wild-type HypA (WT-HypA) to five-coordinate pyramidal in L2*-HypA, which was accompanied by the loss of two N/O donor protein ligands and the addition of an exogenous bromide ligand from the buffer. The magnetic properties of the Ni sites in WT-HypA compared to those of the Ni sites in L2*-HypA confirmed that a spin-state change from high to low spin accompanied this change in structure. The L2*-HypA H. pylori strain was shown to be acid sensitive and deficient in urease activity in vivo. In vitro characterization showed that L2*-HypA did not disrupt the HypA-UreE interaction that is essential for urease maturation but was at least 20-fold weaker in Ni binding than WT-HypA. Characterization of the L2*-HypA variant clearly demonstrates that the N-terminal amine of HypA is involved in proper Ni coordination and is necessary for urease activity and acid survival.

Non-Photolithographic Manufacturing Processes for Micro-Channels Functioned by Micro-Contact-Printed SAMs

Science.gov (United States)

Saigusa, Hiroki; Suga, Yasuo; Miki, Norihisa

In this paper we propose non-photolithographic fabrication processes of micro-fluid channels with patterned SAMs (Self-Assembled-Monolayers). SAMs with a thiol group are micro-contact printed on a patterned Au/Ti layer, which is vapor-deposited through a shadow mask. Ti is an adhesion layer. Subsequently, the micro-channels are formed by bonding surface-activated PDMS onto the silicon substrate via a silanol group, producing a SAMs-functioned bottom wall of the micro-channel. No photolithographic processes are necessary and thus, the proposed processes are very simple, quick and low cost. The micro-reactors can have various functions associated with the micro-contact-printed SAMs. We demonstrate successful manufacturing of micro-reactors with two types of SAMs. The micro-reactor with patterned AUT (11-amino-1-undecanethiol) successfully trapped nano-particles with a carboxylic acid group, indicating that micro-contact-printed SAMs remain active after the manufacturing processes of the micro-reactor. AUT -functioned micro-channels are applicable to bioassay and to immobilize proteins for DNA arrays. ODT (1-octadecanethiol) makes surfaces hydrophobic with the methyl terminal group. When water was introduced into the micro-reactor with ODT-patterned surfaces, water droplets remained only in the hydrophilic areas where ODT was not patterned. ODT -functioned micro-channels are applicable to fluid handling.

Non-invasive vibrational SFG spectroscopy reveals that bacterial adhesion can alter the conformation of grafted "brush" chains on SAM.

Science.gov (United States)

Bulard, Emilie; Guo, Ziang; Zheng, Wanquan; Dubost, Henri; Fontaine-Aupart, Marie-Pierre; Bellon-Fontaine, Marie-Noëlle; Herry, Jean-Marie; Briandet, Romain; Bourguignon, Bernard

2011-04-19

Understanding bacterial adhesion on a surface is a crucial step to design new materials with improved properties or to control biofilm formation and eradication. Sum Frequency Generation (SFG) vibrational spectroscopy has been employed to study in situ the conformational response of a self-assembled monolayer (SAM) of octadecanethiol (ODT) on a gold film to the adhesion of hydrophilic and hydrophobic ovococcoid model bacteria. The present work highlights vibrational SFG spectroscopy as a powerful and unique non-invasive biophysical technique to probe and control bacteria interaction with ordered surfaces. Indeed, the SFG vibrational spectral changes reveal different ODT SAM conformations in air and upon exposure to aqueous solution or bacterial adhesion. Furthermore, this effect depends on the bacterial cell surface properties. The SFG spectral modeling demonstrates that hydrophobic bacteria flatten the ODT SAM alkyl chain terminal part, whereas the hydrophilic ones raise this ODT SAM terminal part. Microorganism-induced alteration of grafted chains can thus affect the desired interfacial functionality, a result that should be considered for the design of new reactive materials. © 2011 American Chemical Society

Sam37 is crucial for formation of the mitochondrial TOM-SAM supercomplex, thereby promoting β-barrel biogenesis.

Science.gov (United States)

Wenz, Lena-Sophie; Ellenrieder, Lars; Qiu, Jian; Bohnert, Maria; Zufall, Nicole; van der Laan, Martin; Pfanner, Nikolaus; Wiedemann, Nils; Becker, Thomas

2015-09-28

Biogenesis of mitochondrial β-barrel proteins requires two preprotein translocases, the general translocase of the outer membrane (TOM) and the sorting and assembly machinery (SAM). TOM and SAM form a supercomplex that promotes transfer of β-barrel precursors. The SAM core complex contains the channel protein Sam50, which cooperates with Sam35 in precursor recognition, and the peripheral membrane protein Sam37. The molecular function of Sam37 has been unknown. We report that Sam37 is crucial for formation of the TOM-SAM supercomplex. Sam37 interacts with the receptor domain of Tom22 on the cytosolic side of the mitochondrial outer membrane and links TOM and SAM complexes. Sam37 thus promotes efficient transfer of β-barrel precursors to the SAM complex. We conclude that Sam37 functions as a coupling factor of the translocase supercomplex of the mitochondrial outer membrane. © 2015 Wenz et al.

Efficient surface enhanced Raman scattering on confeito-like gold nanoparticle-adsorbed self-assembled monolayers.

Science.gov (United States)

Chang, Chia-Chi; Imae, Toyoko; Chen, Liang-Yih; Ujihara, Masaki

2015-12-28

Confeito-like gold nanoparticles (AuNPs; average diameter = 80 nm) exhibiting a plasmon absorption band at 590 nm were adsorbed through immersion-adsorption on two self-assembled monolayers (SAMs) of 3-aminopropyltriethoxysilane (APTES-SAM) and polystyrene spheres coated with amine-terminated poly(amido amine) dendrimers (DEN/PS-SAM). The surface enhanced Raman scattering (SERS) effect on the SAM substrates was examined using the molecules of a probe dye, rhodamine 6G (R6G). The Raman scattering was strongly intensified on both substrates, but the enhancement factor (>10,000) of the AuNP/DEN/PS-SAM hierarchy substrate was 5-10 times higher than that of the AuNP/APTES-SAM substrate. This strong enhancement is attributed to the large surface area of the substrate and the presence of hot spots. Furthermore, analyzing the R6G concentration dependence of SERS suggested that the enhancement mechanism effectively excited the R6G molecules in the first layer on the hot spots and invoked the strong SERS effect. These results indicate that the SERS activity of confeito-like AuNPs on SAM substrates has high potential in molecular electronic devices and ultrasensitive analyses.

[Distribution of biogenic amines in the hippocampal formation in the rabbit].

Science.gov (United States)

Budantsev, A Iu; Gur'ianova, A D

1975-06-01

The hippocampal formation (the hippocampus and the dentate fascia) of the rabbit was studied by histochemical fluorescent method of Falk to determine localization of monoaminergic terminals containing biogenic amines: noradrenalin, dophamine and serotonin. It was shown that monoaminenergic terminals in the hippocampus were in two zones of afferent terminations: in the zone of ending of the perforating way (str. lacunosum-moleculare of fields CA1 and CA2; str. moleculare of the dentate fascia) and in the subgranular zone of the hilum where a part of septofimbrial way terminated on granular neurons of the dentate fascia, the main cellular elements of the hipocampus (pyramidal, granular and basket cells of the hippocampus) did not contain biogenic amines.

Derivatization, characterization, and tribological behavior of an amine-terminated polymer surface

International Nuclear Information System (INIS)

Ren, S.L.; Yang, S.R.; Zhao, Y.P.

2004-01-01

The derivatization, characterization, and micro-tribological behavior of an amine-terminated polymer surface were investigated. Thus, the heptafluorobutyric anhydride (HFBA) derivatized film was characterized by means of contact-angle measurement and X-ray photoelectron spectroscopy (XPS). It was found that the HFBA-derivatized film was generated on the PEI surface in the presence of a chemical amide bond. The tribological properties were characterized as well. The polymer PEI film had relative high adhesion, friction, and poor anti-wear ability, while the HFBA-derivatized polymer film possessed a very low adhesive force of only about 5.5 nN (a pyramidal Si 3 N 4 tip with radius of curvature about 50 nm was used to measure the adhesion), which was more than an order of magnitude lower than that of the silicon substrate surface. Besides, the HFBA-derivatized film registered good friction-reducing ability and thermal stability. Thus, a good alternative method was presented to improve the tribological properties of polymer film by chemisorbing molecules with low surface energy. This makes it feasible for the derivatized polymer film to find promising application in resolving the tribological problems of micro-electromechanical systems (MEMS)

SAM-VI RNAs selectively bind S-adenosylmethionine and exhibit similarities to SAM-III riboswitches.

Science.gov (United States)

Mirihana Arachchilage, Gayan; Sherlock, Madeline E; Weinberg, Zasha; Breaker, Ronald R

2018-03-04

Five distinct riboswitch classes that regulate gene expression in response to the cofactor S-adenosylmethionine (SAM) or its metabolic breakdown product S-adenosylhomocysteine (SAH) have been reported previously. Collectively, these SAM- or SAH-sensing RNAs constitute the most abundant collection of riboswitches, and are found in nearly every major bacterial lineage. Here, we report a potential sixth member of this pervasive riboswitch family, called SAM-VI, which is predominantly found in Bifidobacterium species. SAM-VI aptamers selectively bind the cofactor SAM and strongly discriminate against SAH. The consensus sequence and structural model for SAM-VI share some features with the consensus model for the SAM-III riboswitch class, whose members are mainly found in lactic acid bacteria. However, there are sufficient differences between the two classes such that current bioinformatics methods separately cluster representatives of the two motifs. These findings highlight the abundance of RNA structures that can form to selectively recognize SAM, and showcase the ability of RNA to utilize diverse strategies to perform similar biological functions.

SAM Photovoltaic Model Technical Reference

Energy Technology Data Exchange (ETDEWEB)

Gilman, P. [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2015-05-27

This manual describes the photovoltaic performance model in the System Advisor Model (SAM). The U.S. Department of Energy’s National Renewable Energy Laboratory maintains and distributes SAM, which is available as a free download from https://sam.nrel.gov. These descriptions are based on SAM 2015.1.30 (SSC 41).

Nickel Ligation of the N-Terminal Amine of HypA Is Required for Urease Maturation in Helicobacter pylori

Energy Technology Data Exchange (ETDEWEB)

Hu, Heidi Q. [Department; Johnson, Ryan C. [Microbiology; Merrell, D. Scott [Microbiology; Maroney, Michael J. [Department

2017-02-17

The human pathogen Helicobacter pylori requires nickel for colonization of the acidic environment of the stomach. HypA, a Ni metallochaperone that is typically associated with hydrogenase maturation, is also required for urease maturation and acid survival of H. pylori. There are two proposed Ni site structures for HypA; one is a paramagnetic six-coordinate site characterized by X-ray absorption spectroscopy (XAS) in unmodified HypA, while another is a diamagnetic four-coordinate planar site characterized by solution nuclear magnetic resonance in an N-terminally modified HypA construct. To determine the role of the N-terminal amine in Ni binding of HypA, an N-terminal extension variant, L2*-HypA, in which a leucine residue was inserted into the second position of the amino acid sequence in the proposed Ni-binding motif, was characterized in vitro and in vivo. Structural characterization of the Ni site using XAS showed a coordination change from six-coordinate in wild-type HypA (WT-HypA) to five-coordinate pyramidal in L2*-HypA, which was accompanied by the loss of two N/O donor protein ligands and the addition of an exogenous bromide ligand from the buffer. The magnetic properties of the Ni sites in WT-HypA compared to those of the Ni sites in L2*-HypA confirmed that a spin-state change from high to low spin accompanied this change in structure. The L2*-HypA H. pylori strain was shown to be acid sensitive and deficient in urease activity in vivo. In vitro characterization showed that L2*-HypA did not disrupt the HypA–UreE interaction that is essential for urease maturation but was at least 20-fold weaker in Ni binding than WT-HypA. Characterization of the L2*-HypA variant clearly demonstrates that the N-terminal amine of HypA is involved in proper Ni coordination and is necessary for urease activity and acid survival.

Introduction of 5'-terminal functional groups into synthetic oligonucleotides for selective immobilization

NARCIS (Netherlands)

Bischoff, Rainer; Coull, J.M.; Regnier, F.E.

1987-01-01

Oligodeoxyribonucleotides terminating in a 5'-primary amine group are synthesized using solid-phase supported phosphoramidite chemistry. The 5'-terminal amine group in the deprotected oligomers is further derivatized with either succinic anhydride to give 5'-carboxylic acid or with

Effect of amine substituted at ortho and para positions on the electrochemical and electrocatalytic properties of cobalt porphyrins self-assembled on glassy carbon surface

International Nuclear Information System (INIS)

Muthukumar, Palanisamy; John, S. Abraham

2014-01-01

Highlights: •The self-assembly of ortho and para isomers of Co(II)aminoporphyrin on GCE was studied. •The electrochemical and electrocatalytic properties were examined. •The Co(II)MTpAP showed two redox waves whereas Co(II)MToAP showed a single redox peak. •Both the SAMs greatly catalyzed the dioxigen reduction when compared to GCE. -- Abstract: This work addresses the influence of amine group substituted at para and ortho positions of the phenyl groups on the electrochemical and electrocatalytic properties of cobalt porphyrins self-assembled on glassy carbon electrode (GCE). We have synthesized meso-tetra(para-aminophenyl)porphyrinatocobalt(II) (Co(II)MTpAP) and meso-tetra(ortho-aminophenyl)porphyrinatocobalt(II) (Co(II)MToAP) and were self-assembled on GCE through Michael addition of nucleophilic amine with olefinic GCE surface. Cyclic voltammetry, reflectance spectroscopy and X-ray photoelectron spectroscopy (XPS) techniques were employed to confirm the formation of the self-assembled monolayers (SAMs) of Co(II)MTpAP and Co(II)MToAP on GCEs. Interestingly, the SAM of Co(II)MTpAP in 0.1 M H 2 SO 4 shows two redox waves at 0.37 and 0.60 V whereas the SAM of Co(II)MToAP shows a single redox wave at 0.32 V, indicating the influence of amine group position in the phenyl ring on the redox chemistry of porphyrin. In contrary, the SAMs of the corresponding free base porphyrins prepared under identical conditions show a single redox wave around 0.36 V. Thus, we have assigned the redox wave at 0.37 V to Co(II)Por 1− /Co(II)Por 2− and 0.60 V to Co III/II redox couples for the SAM of Co(II)MTpAP. In the case of Co(II)MToAP, we have assigned the redox wave at 0.32 V due to both Co(II)Por 1− /Co(II)Por 2− and Co III/II . The surface coverage estimated from the charge consumed for the oxidation of Co III/II was used to study the thermodynamics and kinetics of Co(II)MTpAP and Co(II)MToAP self-assembled on GCE. Further, the electrochemical reduction of dioxygen

Diamond surface functionalization with biomimicry - Amine surface tether and thiol moiety for electrochemical sensors

Science.gov (United States)

Sund, James B.; Causey, Corey P.; Wolter, Scott D.; Parker, Charles B.; Stoner, Brian R.; Toone, Eric J.; Glass, Jeffrey T.

2014-05-01

The surface of conducting diamond was functionalized with a terminal thiol group that is capable of binding and detecting nitrogen-oxygen species. The functionalization process employed multiple steps starting with doped diamond films grown by plasma enhanced chemical vapor deposition followed by hydrogen termination and photochemical attachment of a chemically protected amine alkene. The surface tether was deprotected to reveal the amine functionality, which enabled the tether to be extended with surface chemistry to add a terminal thiol moiety for electrochemical sensing applications. Each step of the process was validated using X-ray photoelectron spectroscopy analysis.

Mechanism underlying bioinertness of self-assembled monolayers of oligo(ethyleneglycol)-terminated alkanethiols on gold: protein adsorption, platelet adhesion, and surface forces.

Science.gov (United States)

Hayashi, Tomohiro; Tanaka, Yusaku; Koide, Yuki; Tanaka, Masaru; Hara, Masahiko

2012-08-07

The mechanism underlying the bioinertness of the self-assembled monolayers of oligo(ethylene glycol)-terminated alkanethiol (OEG-SAM) was investigated with protein adsorption experiments, platelet adhesion tests, and surface force measurements with an atomic force microscope (AFM). In this work, we performed systematic analysis with SAMs having various terminal groups (-OEG, -OH, -COOH, -NH(2), and -CH(3)). The results of the protein adsorption experiment by the quartz crystal microbalance (QCM) method suggested that having one EG unit and the neutrality of total charges of the terminal groups are essential for protein-resistance. In particular, QCM with energy dissipation analyses indicated that proteins absorb onto the OEG-SAM via a very weak interaction compared with other SAMs. Contrary to the protein resistance, at least three EG units as well as the charge neutrality of the SAM are found to be required for anti-platelet adhesion. When the identical SAMs were formed on both AFM probe and substrate, our force measurements revealed that only the OEG-SAMs possessing more than two EG units showed strong repulsion in the range of 4 to 6 nm. In addition, we found that the SAMs with other terminal groups did not exhibit such repulsion. The repulsion between OEG-SAMs was always observed independent of solution conditions [NaCl concentration (between 0 and 1 M) and pH (between 3 and 11)] and was not observed in solution mixed with ethanol, which disrupts the three-dimensional network of the water molecules. We therefore concluded that the repulsion originated from structured interfacial water molecules. Considering the correlation between the above results, we propose that the layer of the structured interfacial water with a thickness of 2 to 3 nm (half of the range of the repulsion observed in the surface force measurements) plays an important role in deterring proteins and platelets from adsorption or adhesion.

SAM Theory Manual

Energy Technology Data Exchange (ETDEWEB)

Hu, Rui [Argonne National Lab. (ANL), Argonne, IL (United States)

2017-03-01

The System Analysis Module (SAM) is an advanced and modern system analysis tool being developed at Argonne National Laboratory under the U.S. DOE Office of Nuclear Energy’s Nuclear Energy Advanced Modeling and Simulation (NEAMS) program. SAM development aims for advances in physical modeling, numerical methods, and software engineering to enhance its user experience and usability for reactor transient analyses. To facilitate the code development, SAM utilizes an object-oriented application framework (MOOSE), and its underlying meshing and finite-element library (libMesh) and linear and non-linear solvers (PETSc), to leverage modern advanced software environments and numerical methods. SAM focuses on modeling advanced reactor concepts such as SFRs (sodium fast reactors), LFRs (lead-cooled fast reactors), and FHRs (fluoride-salt-cooled high temperature reactors) or MSRs (molten salt reactors). These advanced concepts are distinguished from light-water reactors in their use of single-phase, low-pressure, high-temperature, and low Prandtl number (sodium and lead) coolants. As a new code development, the initial effort has been focused on modeling and simulation capabilities of heat transfer and single-phase fluid dynamics responses in Sodium-cooled Fast Reactor (SFR) systems. The system-level simulation capabilities of fluid flow and heat transfer in general engineering systems and typical SFRs have been verified and validated. This document provides the theoretical and technical basis of the code to help users understand the underlying physical models (such as governing equations, closure models, and component models), system modeling approaches, numerical discretization and solution methods, and the overall capabilities in SAM. As the code is still under ongoing development, this SAM Theory Manual will be updated periodically to keep it consistent with the state of the development.

SAM Photovoltaic Model Technical Reference 2016 Update

Energy Technology Data Exchange (ETDEWEB)

Gilman, Paul [National Renewable Energy Laboratory (NREL), Golden, CO (United States); DiOrio, Nicholas A [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Freeman, Janine M [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Janzou, Steven [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Dobos, Aron [No longer NREL employee; Ryberg, David [No longer NREL employee

2018-03-19

This manual describes the photovoltaic performance model in the System Advisor Model (SAM) software, Version 2016.3.14 Revision 4 (SSC Version 160). It is an update to the 2015 edition of the manual, which describes the photovoltaic model in SAM 2015.1.30 (SSC 41). This new edition includes corrections of errors in the 2015 edition and descriptions of new features introduced in SAM 2016.3.14, including: 3D shade calculator Battery storage model DC power optimizer loss inputs Snow loss model Plane-of-array irradiance input from weather file option Support for sub-hourly simulations Self-shading works with all four subarrays, and uses same algorithm for fixed arrays and one-axis tracking Linear self-shading algorithm for thin-film modules Loss percentages replace derate factors. The photovoltaic performance model is one of the modules in the SAM Simulation Core (SSC), which is part of both SAM and the SAM SDK. SAM is a user-friedly desktop application for analysis of renewable energy projects. The SAM SDK (Software Development Kit) is for developers writing their own renewable energy analysis software based on SSC. This manual is written for users of both SAM and the SAM SDK wanting to learn more about the details of SAM's photovoltaic model.

Crystal structures of the SAM-III/S[subscript MK] riboswitch reveal the SAM-dependent translation inhibition mechanism

Energy Technology Data Exchange (ETDEWEB)

Lu, C.; Smith, A.M.; Fuchs, R.T.; Ding, F.; Rajashankar, K.; Henkin, T.M.; Ke, A. (Cornell); (OSU)

2010-01-07

Three distinct classes of S-adenosyl-L-methionine (SAM)-responsive riboswitches have been identified that regulate bacterial gene expression at the levels of transcription attenuation or translation inhibition. The SMK box (SAM-III) translational riboswitch has been identified in the SAM synthetase gene in members of the Lactobacillales. Here we report the 2.2-{angstrom} crystal structure of the Enterococcus faecalis SMK box riboswitch. The Y-shaped riboswitch organizes its conserved nucleotides around a three-way junction for SAM recognition. The Shine-Dalgarno sequence, which is sequestered by base-pairing with the anti-Shine-Dalgarno sequence in response to SAM binding, also directly participates in SAM recognition. The riboswitch makes extensive interactions with the adenosine and sulfonium moieties of SAM but does not appear to recognize the tail of the methionine moiety. We captured a structural snapshot of the SMK box riboswitch sampling the near-cognate ligand S-adenosyl-L-homocysteine (SAH) in which SAH was found to adopt an alternative conformation and fails to make several key interactions.

Redox Behavior of the S-Adenosylmethionine (SAM)-Binding Fe-S Cluster in Methylthiotransferase RimO, toward Understanding Dual SAM Activity.

Science.gov (United States)

Molle, Thibaut; Moreau, Yohann; Clemancey, Martin; Forouhar, Farhad; Ravanat, Jean-Luc; Duraffourg, Nicolas; Fourmond, Vincent; Latour, Jean-Marc; Gambarelli, Serge; Mulliez, Etienne; Atta, Mohamed

2016-10-18

RimO, a radical-S-adenosylmethionine (SAM) enzyme, catalyzes the specific C 3 methylthiolation of the D89 residue in the ribosomal S 12 protein. Two intact iron-sulfur clusters and two SAM cofactors both are required for catalysis. By using electron paramagnetic resonance, Mössbauer spectroscopies, and site-directed mutagenesis, we show how two SAM molecules sequentially bind to the unique iron site of the radical-SAM cluster for two distinct chemical reactions in RimO. Our data establish that the two SAM molecules bind the radical-SAM cluster to the unique iron site, and spectroscopic evidence obtained under strongly reducing conditions supports a mechanism in which the first molecule of SAM causes the reoxidation of the reduced radical-SAM cluster, impeding reductive cleavage of SAM to occur and allowing SAM to methylate a HS - ligand bound to the additional cluster. Furthermore, by using density functional theory-based methods, we provide a description of the reaction mechanism that predicts the attack of the carbon radical substrate on the methylthio group attached to the additional [4Fe-4S] cluster.

Diamond surface functionalization with biomimicry – Amine surface tether and thiol moiety for electrochemical sensors

Energy Technology Data Exchange (ETDEWEB)

Sund, James B., E-mail: jim@jamessund.com [Department of Electrical and Computer Engineering, Duke University, Durham, NC (United States); Causey, Corey P. [Departments of Chemistry and Biochemistry, Duke University, Durham, NC (United States); Wolter, Scott D. [Department of Physics, Elon University, Elon, NC 27244 (United States); Parker, Charles B., E-mail: charles.parker@duke.edu [Department of Electrical and Computer Engineering, Duke University, Durham, NC (United States); Stoner, Brian R. [Department of Electrical and Computer Engineering, Duke University, Durham, NC (United States); Research Triangle Institute (RTI) International, Research Triangle Park, NC (United States); Toone, Eric J. [Departments of Chemistry and Biochemistry, Duke University, Durham, NC (United States); Glass, Jeffrey T. [Department of Electrical and Computer Engineering, Duke University, Durham, NC (United States)

2014-05-01

Highlights: • Diamond surfaces were functionalized with organic molecules using a novel approach. • Used biomimicry to select a molecule to bind NO, similar to the human body. • Molecular orbital theory predicted the molecule-analyte oxidation behavior. • A thiol moiety was attached to an amine surface tether on the diamond surface. • XPS analysis verified each surface functionalization step. - Abstract: The surface of conducting diamond was functionalized with a terminal thiol group that is capable of binding and detecting nitrogen–oxygen species. The functionalization process employed multiple steps starting with doped diamond films grown by plasma enhanced chemical vapor deposition followed by hydrogen termination and photochemical attachment of a chemically protected amine alkene. The surface tether was deprotected to reveal the amine functionality, which enabled the tether to be extended with surface chemistry to add a terminal thiol moiety for electrochemical sensing applications. Each step of the process was validated using X-ray photoelectron spectroscopy analysis.

Diamond surface functionalization with biomimicry – Amine surface tether and thiol moiety for electrochemical sensors

International Nuclear Information System (INIS)

Sund, James B.; Causey, Corey P.; Wolter, Scott D.; Parker, Charles B.; Stoner, Brian R.; Toone, Eric J.; Glass, Jeffrey T.

2014-01-01

Highlights: • Diamond surfaces were functionalized with organic molecules using a novel approach. • Used biomimicry to select a molecule to bind NO, similar to the human body. • Molecular orbital theory predicted the molecule-analyte oxidation behavior. • A thiol moiety was attached to an amine surface tether on the diamond surface. • XPS analysis verified each surface functionalization step. - Abstract: The surface of conducting diamond was functionalized with a terminal thiol group that is capable of binding and detecting nitrogen–oxygen species. The functionalization process employed multiple steps starting with doped diamond films grown by plasma enhanced chemical vapor deposition followed by hydrogen termination and photochemical attachment of a chemically protected amine alkene. The surface tether was deprotected to reveal the amine functionality, which enabled the tether to be extended with surface chemistry to add a terminal thiol moiety for electrochemical sensing applications. Each step of the process was validated using X-ray photoelectron spectroscopy analysis

Amine functionalized nanodiamond promotes cellular adhesion, proliferation and neurite outgrowth

International Nuclear Information System (INIS)

Hopper, A P; Dugan, J M; Gill, A A; Haycock, J W; Claeyssens, F; Fox, O J L; May, P W

2014-01-01

In this study, we report the production of amine functionalized nanodiamond. The amine functionalized nanodiamond forms a conformal monolayer on a negatively charged surface produced via plasma polymerization of acrylic acid. Nanodiamond terminated surfaces were studied as substrates for neuronal cell culture. NG108-15 neuroblastoma-glyoma hybrid cells were successfully cultured upon amine functionalized nanodiamond coated surfaces for between 1 and 7 d. Additionally, primary dorsal root ganglion (DRG) neurons and Schwann cells isolated from Wistar rats were also successfully cultured over a period of 21 d illustrating the potential of the coating for applications in the treatment of peripheral nerve injury. (paper)

SAM International Case Studies: DPV Analysis in Mexico

Energy Technology Data Exchange (ETDEWEB)

McCall, James D [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2018-03-28

Presentation demonstrates the use of the System Advisor Model (SAM) in international analyses, specifically Mexico. Two analyses are discussed with relation to SAM modelling efforts: 1) Customer impacts from changes to net metering and billing agreements and 2) Potential benefits of PV for Mexican solar customers, the Mexican Treasury, and the environment. Along with the SAM analyses, integration of the International Utility Rate Database (I-URDB) with SAM and future international SAM work are discussed. Presentation was created for the International Solar Energy Society's (ISES) webinar titled 'International use of the NREL System Advisor Model (SAM) with case studies'.

War Termination, Identity Conflict, and Genocide: A Road Map

Science.gov (United States)

2012-05-17

of The Cambodian Genocide Project, and the Vice President of the International Association of Genocide Scholars. 10 Genocide Watch, “About Genocide ...Approved for Public Release; Distribution is Unlimited War Termination, Identity Conflict, and Genocide : A Road Map A Monograph by MAJ Stephen...TYPE SAMS Monograph 3. DATES COVERED (From - To) JUN 2011 – MAY 2012 4. TITLE AND SUBTITLE War Termination, Identity Conflict, and Genocide : A

Electrochemistry of 2-dimethylaminoethanethiol SAM on gold electrode: Interaction with SWCNT-poly(m-aminobenzene sulphonic acid), electric field-induced protonation-deprotonation, and surface pKa

CSIR Research Space (South Africa)

Pillay, J

2009-06-01

Full Text Available -called electric field induced protonation-deprotonation process, hitherto observed for the -COOH terminated SAMs, is also observed for the -N(H)+(CH3)2 terminated. The surface pKa of DMAET was estimated as 7.6, smaller than its solution pKa of 10.8. It is also...

Purification and characterization of the amine dehydrogenase from a facultative methylotroph.

Science.gov (United States)

Coleman, J P; Perry, J J

1984-01-01

Strain RA-6 is a pink-pigmented organism which can grow on a variety of substrates including methylamine. It can utilize methylamine as sole source of carbon via an isocitrate lyase negative serine pathway. Methylamine grown cells contain an inducible primary amine dehydrogenase [primary amine: (acceptor) oxidoreductase (deaminating)] which is not present in succinate grown cells. The amine dehydrogenase was purified to over 90% homogeneity. It is an acidic protein (isoelectric point of 5.37) with a molecular weight of 118,000 containing subunits with approximate molecular weights of 16,500 and 46,000. It is active on an array of primary terminal amines and is strongly inhibited by carbonyl reagents. Cytochrome c or artificial electron acceptors are required for activity; neither NAD nor NADP can serve as primary electron acceptor.

Samsø Energy Vision 2030

DEFF Research Database (Denmark)

Mathiesen, Brian Vad; Hansen, Kenneth; Ridjan, Iva

The purpose of this report is to investigate potential scenarios for converting Samsø into 100% renewable energy supply in 2030 with focus on local electricity and biomass resources. Firstly, a 2013 reference scenario is established to investigate whether Samsø is 100% renewable today. Next, scen...

System for Award Management (SAM) API

Data.gov (United States)

General Services Administration — The SAM API is a RESTful method of retrieving public information about the businesses, organizations, or individuals (referred to as entities) within the SAM entity...

Interaction of amines with native aluminium oxide layers in non-aqueous environment: Application to the understanding of the formation of epoxy-amine/metal interphases

International Nuclear Information System (INIS)

Mercier, D.; Rouchaud, J.-C.; Barthes-Labrousse, M.-G.

2008-01-01

Interaction of propylamine (PA), 1,2-diaminoethane (DAE) or 3-aminomethyl-3,5,5-trimethylcyclohexylamine (isophorone diamine, IPDA) with native aluminium oxide layers in non-aqueous environment has been studied using time-resolved inductively coupled plasma optical emission spectroscopy (ICP-OES) and X-ray photoelectron spectroscopy (XPS). The formation of several surface complexes has been evidenced. Monodentate and bidentate metal-bond surface complexes (MBSC) result from interactions between the amine terminations of the molecule and aluminium cations by donation of the N lone electron pair to the metal ion (Lewis-like mechanism leading to O-Al...N bonds). Monodentate and bidentate hydrogen-bond surface complexes (HBSC) are due to interaction of the amino group with surface hydroxyl groups by protonation of the amine termination (Bronsted-like mechanism leading to the formation of Al-OH...N bonds) or interaction with carbonaceous contamination (C x O y H z ...N bonds). Diamines can also form mixed complexes with one amino group forming an O-Al...N bond and the other group forming an Al-OH...N or C x O y H z ...N bond. Al-OH...N and C x O y H z ...N bonds are less stable under vacuum than O-Al...N bonds, leading to partial desorption of the DAE molecules in vacuum and modification of the interaction modes. Only DAE and IPDA can lead to partial dissolution of the aluminium native (hydr)oxide films. A detailed mechanism of dissolution has been proposed based on the formation of mononuclear bidentate (chelate) MBSC by ligand exchange between the terminal η 1 -OH and bridged μ 2 -OH surface sites and the amino terminations of the molecule. The detachment of this complex from the surface is likely to be the precursor step to the formation of the interphase in epoxy-amine/metal systems

78 FR 62627 - Sam Rayburn Dam Rate

Science.gov (United States)

2013-10-22

..., Wholesale Rates for Hydro Power and Energy Sold to Sam Rayburn Dam Electric Cooperative, Inc. (Contract No... Schedule SRD-08, Wholesale Rates for Hydro Power and Energy Sold to Sam Rayburn Dam Electric Cooperative... ADMINISTRATION RATE SCHEDULE SRD-13 \\1\\ WHOLESALE RATES FOR HYDRO POWER AND ENERGY SOLD TO SAM RAYBURN DAM...

Enhancing amine terminals in an amine-deprived collagen matrix.

LENUS (Irish Health Repository)

Tiong, William H C

2008-10-21

Collagen, though widely used as a core biomaterial in many clinical applications, is often limited by its rapid degradability which prevents full exploitation of its potential in vivo. Polyamidoamine (PAMAM) dendrimer, a highly branched macromolecule, possesses versatile multiterminal amine surface groups that enable them to be tethered to collagen molecules and enhance their potential. In this study, we hypothesized that incorporation of PAMAM dendrimer in a collagen matrix through cross-linking will result in a durable, cross-linked collagen biomaterial with free -NH 2 groups available for further multi-biomolecular tethering. The aim of this study was to assess the physicochemical properties of a G1 PAMAM cross-linked collagen matrix and its cellular sustainability in vitro. Different amounts of G1 PAMAM dendrimer (5 or 10 mg) were integrated into bovine-derived collagen matrices through a cross-linking process, mediated by 5 or 25 mM 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) in 5 mM N-hydroxysuccinimide (NHS) and 50 mM 2-morpholinoethane sulfonic acid buffer at pH 5.5. The physicochemical properties of resultant matrices were investigated with scanning electron microscopy (SEM), collagenase degradation assay, differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) spectra, and ninhydrin assay. Cellular sustainability of the matrices was assessed with Alamar Blue assay and SEM. There was no significant difference in cellular behavior between the treated and nontreated groups. However, the benefit of incorporating PAMAM in the cross-linking reaction was limited when higher concentrations of either agent were used. These results confirm the hypothesis that PAMAM dendrimer can be incorporated in the collagen cross-linking process in order to modulate the properties of the resulting cross-linked collagen biomaterial with free -NH 2 groups available for multi-biomolecular tethering.

Preparation of Substituted Enol Derivatives From Terminal Alkynes and Their Synthetic Utility

Science.gov (United States)

DeBergh, John R.; Spivey, Kathleen M.; Ready, Joseph M.

2009-01-01

Stereodefined enol derivatives of aldehydes are prepared from terminal alkynes. Specifically, terminal alkynes are known to undergo Cp2ZrCl2-catalyzed methylalumination. Here, we show that the resultant vinylalanes can be oxygenated with peroxyzinc species to generate trisubstituted enolates. Electrophilic trapping with carboxylic anydrides or silyl triflates yields trisubstituted enol esters or silanes, respectively. The tandem carbometalation/oxygenation tolerates free and protected alcohols, heterocycles, olefins and nitriles. Likewise, amination can be accomplished using azodicarboxylates. Stereodefined enol esters can undergo asymmetric dihydroxylation to yield optically-active α-hydroxy aldehydes. Reduction with NaBH4 provides the diols of 1,1-disubstituted olefins in excellent ee. An application of this methodology to the enantioselective synthesis of the insect pheromone frontalin is presented. Finally, α-hydroxy aldehydes are shown to undergo homologation to a terminal alkyne, reductive amination, oxidation and olefination. Preliminary results indicate that tandem carbometalation/amination can be accomplished with azodicarboxylates. In this way, ene-hydrazines are formed in excellent yield. PMID:18517202

System Advisor Model, SAM 2014.1.14: General Description

Energy Technology Data Exchange (ETDEWEB)

Blair, Nate [National Renewable Energy Lab. (NREL), Golden, CO (United States); Dobos, Aron P. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Freeman, Janine [National Renewable Energy Lab. (NREL), Golden, CO (United States); Neises, Ty [National Renewable Energy Lab. (NREL), Golden, CO (United States); Wagner, Michael [National Renewable Energy Lab. (NREL), Golden, CO (United States); Ferguson, Tom [Global Resources, Northbrook, IL (United States); Gilman, Paul [National Renewable Energy Lab. (NREL), Golden, CO (United States); Janzou, Steven [Janzou Consulting, Idaho Springs, CO (United States)

2014-02-01

This document describes the capabilities of the U.S. Department of Energy and National Renewable Energy Laboratory's System Advisor Model (SAM), Version 2013.9.20, released on September 9, 2013. SAM is a computer model that calculates performance and financial metrics of renewable energy systems. Project developers, policy makers, equipment manufacturers, and researchers use graphs and tables of SAM results in the process of evaluating financial, technology, and incentive options for renewable energy projects. SAM simulates the performance of photovoltaic, concentrating solar power, solar water heating, wind, geothermal, biomass, and conventional power systems. The financial model can represent financial structures for projects that either buy and sell electricity at retail rates (residential and commercial) or sell electricity at a price determined in a power purchase agreement (utility). SAM's advanced simulation options facilitate parametric and sensitivity analyses, and statistical analysis capabilities are available for Monte Carlo simulation and weather variability (P50/P90) studies. SAM can also read input variables from Microsoft Excel worksheets. For software developers, the SAM software development kit (SDK) makes it possible to use SAM simulation modules in their applications written in C/C++, C#, Java, Python, and MATLAB. NREL provides both SAM and the SDK as free downloads at http://sam.nrel.gov. Technical support and more information about the software are available on the website.

Tris{2-[(2-aminobenzylideneamino]ethyl}amine

Directory of Open Access Journals (Sweden)

Perla Elizondo Martínez

2010-12-01

Full Text Available The title Schiff base, C27H33N7, is a tripodal amine displaying C3 symmetry, with the central tertiary N atom lying on the threefold crystallographic axis. The N—CH2—CH2—N conformation of the pendant arms is gauche [torsion angle = 76.1 (3°], which results in a claw-like molecule, with the terminal aniline groups wrapped around the symmetry axis. The lone pair of the apical N atom is clearly oriented inwards towards the cavity, and should thus be chemically inactive. The amine NH2 substituents lie in the plane of the benzene ring to which they are bonded. With such an arrangement, one amine H atom forms an S(6 motif through a weak N—H...N hydrogen bond with the imine N atom, while the other is engaged in an intermolecular N—H...π contact involving the benzene ring of a neighbouring molecule related by inversion. The benzene rings also participate in an intramolecular C—H...π contact of similar strength. In the crystal structure, molecules are separated by empty voids (ca 5% of the crystal volume, although the crystal seems to be unsolvated.

核蛋白Sam68的原核表达及鉴定%Prokaryotic Expression and Identification of Nuclear Protein Sam68

Institute of Scientific and Technical Information of China (English)

张华; 陈宁; 丁筠; 邹德华; 潘子夜; 李鹏飞; 李丽阳; 肖丽杰; 曹宏伟

2017-01-01

为了构建pGEX-4T-1-Sam68原核表达载体,表达并鉴定GST-Sam68融合蛋白,采用PCR扩增Sam68基因,插入pGEX-4T-1的EcoR I和Sal I位点,并转化Rosetta(DE3)大肠杆菌,IPTG诱导表达,SDS-PAGE和Western Blot验证蛋白表达,GST pull-down技术验证Sam68的结合活性.酶切和测序结果证实Sam68基因正确插入pGEX-4T-1载体中,载体能够在Rosetta(DE3)细胞中正确表达,且纯化的GST-Sam68蛋白具有与PI3K p85特异结合的活性,说明成功构建了原核表达载体pGEX-4T-1-Sam68.

pH-sensitive diamond field-effect transistors (FETs) with directly aminated channel surface

International Nuclear Information System (INIS)

Song, Kwang-Soup; Nakamura, Yusuke; Sasaki, Yuichi; Degawa, Munenori; Yang, Jung-Hoon; Kawarada, Hiroshi

2006-01-01

We have introduced pH sensors fabricated on diamond thin films through modification of the surface-terminated atom. We directly modified the diamond surface from hydrogen to amine or oxygen with ultraviolet (UV) irradiation under ammonia gas. The quantified amine site based on the spectra obtained by X-ray photoelectron spectroscopy (XPS) is 26% (2.6 x 10 14 cm -2 ) with UV irradiation for 8 h and its coverage is dependent on the UV irradiation time. This directly aminated diamond surface is stable with long-term exposure in air and electrolyte solution. We fabricated diamond solution-gate field-effect transistors (SGFETs) without insulating layers on the channel surface. These diamond SGFETs with amine modified by direct amination are sensitive to pH (45 mV/pH) over a wide range from pH 2 to 12 and their sensitivity is dependent on the density of binding sites corresponding to UV irradiation time on the channel surface

Anomalous length dependence of conductance of aromatic nanoribbons with amine anchoring groups

KAUST Repository

Bilić, Ante; Sanvito, Stefano

2012-01-01

for longer members of the series. The oligoperylene nanoribbons, with dual amine groups at both terminals, show the potential to fully harness the highly conjugated system of π molecular orbitals across the junction. © 2012 American Physical Society.

Tailoring Enzyme-Like Activities of Gold Nanoclusters by Polymeric Tertiary Amines for Protecting Neurons Against Oxidative Stress.

Science.gov (United States)

Liu, Ching-Ping; Wu, Te-Haw; Lin, Yu-Lung; Liu, Chia-Yeh; Wang, Sabrina; Lin, Shu-Yi

2016-08-01

The cytotoxicity of nanozymes has drawn much attention recently because their peroxidase-like activity can decompose hydrogen peroxide (H2 O2 ) to produce highly toxic hydroxyl radicals (•OH) under acidic conditions. Although catalytic activities of nanozymes are highly associated with their surface properties, little is known about the mechanism underlying the surface coating-mediated enzyme-like activities. Herein, it is reported for the first time that amine-terminated PAMAM dendrimer-entrapped gold nanoclusters (AuNCs-NH2 ) unexpectedly lose their peroxidase-like activity while still retaining their catalase-like activity in physiological conditions. Surprisingly, the methylated form of AuNCs-NH2 (i.e., MAuNCs-N(+) R3 , where R = H or CH3 ) results in a dramatic recovery of the intrinsic peroxidase-like activity while blocking most primary and tertiary amines (1°- and 3°-amines) of dendrimers to form quaternary ammonium ions (4°-amines). However, the hidden peroxidase-like activity is also found in hydroxyl-terminated dendrimer-encapsulated AuNCs (AuNCs-OH, inside backbone with 3°-amines), indicating that 3°-amines are dominant in mediating the peroxidase-like activity. The possible mechanism is further confirmed that the enrichment of polymeric 3°-amines on the surface of dendrimer-encapsulated AuNCs provides sufficient suppression of the critical mediator •OH for the peroxidase-like activity. Finally, it is demonstrated that AuNCs-NH2 with diminished cytotoxicity have great potential for use in primary neuronal protection against oxidative damage. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Storifying Samsøs Renewable Energy Transition

DEFF Research Database (Denmark)

Papazu, Irina

2018-01-01

Through a joint community effort Denmark’s Renewable Energy Island Samsø became self-sufficient with renewable energy over a period of 10 years from 1997 to 2007. Today, the story about Samsø’s successful energy transition has become a global export and a widely known model of community building...... the effects of such well-crafted transition narratives. This tendency toward the ‘storification’ of transition processes is not restricted to Samsø; it is employed as a tactics by environmental organizations operating globally....

Understanding the effects of packing and chemical terminations on the optical excitations of azobenzene-functionalized self-assembled monolayers

Science.gov (United States)

Cocchi, Caterina; Draxl, Claudia

2017-10-01

In a first-principles study based on many-body perturbation theory, we analyze the optical excitations of azobenzene-functionalized self-assembled monolayers (SAMs) with increasing packing density and different terminations, considering for comparison the corresponding gas-phase molecules and dimers. Intermolecular coupling increases with the density of the chromophores independently of the functional groups. The intense π → π* resonance that triggers photo-isomerization is present in the spectra of isolated dimers and diluted SAMs, but it is almost completely washed out in tightly packed architectures. Intermolecular coupling is partially inhibited by mixing differently functionalized azobenzene derivatives, in particular when large groups are involved. In this way, the excitation band inducing the photo-isomerization process is partially preserved and the effects of dense packing partly counterbalanced. Our results suggest that a tailored design of azobenzene-functionalized SAMs which optimizes the interplay between the packing density of the chromophores and their termination can lead to significant improvements in the photo-switching efficiency of these systems.

Samâ’ dalam Tradisi Tasawuf

Directory of Open Access Journals (Sweden)

Said Aqil Siradj

2014-01-01

Full Text Available Samâ‘ in Tasawuf has been a very important element in the dissemination of this spiritual dimension of Islam. Yet, it has received very little both from the practitioners of Tasawuf and its intellectuals. This paper tries to expose this simply in a hope to make it heard in the academic and popular circle. Here, samâ‘ is not only understood as a form of music, as many would do, but also as an art of listening of which music is certainly part. The paper will explore the meaning and definition of this term, putting emphasis on its many-faceted function in the formation and development of one’s soul and spirituality. It is argued that soul is musical and artistic. Using art and music to talk to soul is therefore the proper way and means. The paper will also try to show that samâ‘ is also an indispensable part of spiritual method to reach and know God. Knowledge of God in other words, can be gained through this practice. Hence, samâ‘ is treated not only as a form of entertainment, but also a kind of practical epistemology.

Highly efficient and diastereoselective gold(I)-catalyzed synthesis of tertiary amines from secondary amines and alkynes: substrate scope and mechanistic insights.

Science.gov (United States)

Liu, Xin-Yuan; Guo, Zhen; Dong, Sijia S; Li, Xiao-Hua; Che, Chi-Ming

2011-11-11

An efficient method for the synthesis of tertiary amines through a gold(I)-catalyzed tandem reaction of alkynes with secondary amines has been developed. In the presence of ethyl Hantzsch ester and [{(tBu)(2)(o-biphenyl)P}AuCl]/AgBF(4) (2 mol %), a variety of secondary amines bearing electron-deficient and electron-rich substituents and a wide range of alkynes, including terminal and internal aryl alkynes, aliphatic alkynes, and electron-deficient alkynes, underwent a tandem reaction to afford the corresponding tertiary amines in up to 99 % yield. For indolines bearing a preexisting chiral center, their reactions with alkynes in the presence of ethyl Hantzsch ester catalyzed by [{(tBu)(2)(o-biphenyl)P}AuCl]/AgBF(4) (2 mol %) afforded tertiary amines in excellent yields and with good to excellent diastereoselectivity. All of these organic transformations can be conducted as a one-pot reaction from simple and readily available starting materials without the need of isolation of air/moisture-sensitive enamine intermediates, and under mild reaction conditions (mostly room temperature and mild reducing agents). Mechanistic studies by NMR spectroscopy, ESI-MS, isotope labeling studies, and DFT calculations on this gold(I)-catalyzed tandem reaction reveal that the first step involving a monomeric cationic gold(I)-alkyne intermediate is more likely than a gold(I)-amine intermediate, a three-coordinate gold(I) intermediate, or a dinuclear gold(I)-alkyne intermediate. These studies also support the proposed reaction pathway, which involves a gold(I)-coordinated enamine complex as a key intermediate for the subsequent transfer hydrogenation with a hydride source, and reveal the intrinsic stereospecific nature of these transformations observed in the experiments. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The nuclear protein Sam68 is cleaved by the FMDV 3C protease redistributing Sam68 to the cytoplasm during FMDV infection of host cells

International Nuclear Information System (INIS)

Lawrence, Paul; Schafer, Elizabeth A.; Rieder, Elizabeth

2012-01-01

Picornavirus infection can lead to disruption of nuclear pore traffic, shut-off of cell translation machinery, and cleavage of proteins involved in cellular signal transduction and the innate response to infection. Here, we demonstrated that the FMDV 3C pro induced the cleavage of nuclear RNA-binding protein Sam68 C-terminus containing the nuclear localization sequence (NLS). Consequently, it stimulated the redistribution of Sam68 to the cytoplasm. The siRNA knockdown of Sam68 resulted in a 1000-fold reduction in viral titers, which prompted us to study the effect of Sam68 on FMDV post-entry events. Interestingly, Sam68 interacts with the internal ribosomal entry site within the 5′ non-translated region of the FMDV genome, and Sam68 knockdown decreased FMDV IRES-driven activity in vitro suggesting that it could modulate translation of the viral genome. The results uncover a novel role for Sam68 in the context of picornaviruses and the proteolysis of a new cellular target of the FMDV 3C pro .

Influencia del Estado de Oxidación del Ión Cobalto en la Estabilidad de Electrodos Modificados con Monocapas SAM-TOA-ANTA-Con+-HRP-NHis.

Directory of Open Access Journals (Sweden)

Pedro R. Matheus*

Full Text Available Influence of state oxidation of cobalt ion in the stability electrodes modified with monolayers SAM-TOA-ANTA-Con+-HRP-NHis. Quartz Crystal Microbalance (QCM was used to investigate the adsorption of the HRP-NHis enzyme (horseradish peroxidase, which was modified by the addition of a tail of six histidine on its extreme N-terminal. The QCM operating at flow of 0.025 mL min-1 on a crystal whose gold electrode was modified with monolayers of SAM-TOA-ANTA-Co2+ and SAM-TOA-ANTA -Co3+. The oxidize form was obtained from the electrochemical oxidation of a monolayer of SAM-TOA-ANTA-Co2+. The results suggest that the HRP-NHis is attached to both monolayers in a similar way; on the contrary, the desortion of the attached protein is dramatically different. Thus, whereas the ligand-Co2+ bonds are reversible, which allows that the anchored protein is easily replaced by imidazol molecules. The 3+ oxidation state of the metal does not allow the interchange of protein by the imidazol molecules.

Technical Manual for the SAM Physical Trough Model

Energy Technology Data Exchange (ETDEWEB)

Wagner, M. J.; Gilman, P.

2011-06-01

NREL, in conjunction with Sandia National Lab and the U.S Department of Energy, developed the System Advisor Model (SAM) analysis tool for renewable energy system performance and economic analysis. This paper documents the technical background and engineering formulation for one of SAM's two parabolic trough system models in SAM. The Physical Trough model calculates performance relationships based on physical first principles where possible, allowing the modeler to predict electricity production for a wider range of component geometries than is possible in the Empirical Trough model. This document describes the major parabolic trough plant subsystems in detail including the solar field, power block, thermal storage, piping, auxiliary heating, and control systems. This model makes use of both existing subsystem performance modeling approaches, and new approaches developed specifically for SAM.

Surface characterization on binary nano/micro-domain composed of alkyl- and amino-terminated self-assembled monolayer

Energy Technology Data Exchange (ETDEWEB)

Lee, S.H. [Faculty of Engineering, Shinshu University, 4-17-1 Wakasato, Nagano 380-8553 (Japan); Ishizaki, T. [Materials Research Institute for Sustainable Development, National Institute of Advanced Industrial Science and Technology, 2266-98 Anagahora, Shimo-Shidami, Moriyama-ku, Nagoya 463-8560 (Japan); Saito, N. [Department of Molecular Design and Engineering, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa, Nagano 464-8603 (Japan)], E-mail: hiro@eco-t.esi.nagoya-u.ac.jp; Takai, O. [EcoTopia Science Institute, Nagoya University, Furo-cho, Chikusa, Nagoya 464-8603 (Japan)

2008-09-15

The binary alkyl- and amino-terminated self-assembled monolayers (SAMs) composed of nano/micro-sized domains was prepared though a self-assembly technique. In addition, the wetting and electrostatic property of the binary SAMs was investigated by the analysis of the static and dynamic water contact angle and zeta-potentials measurement. The binary SAMs were also characterized by atomic force microscope (AFM), Kelvin probe force microscope (KPFM) and X-ray photoelectron spectroscopy (XPS). The domains on the binary SAMs were observed in topographic and surface potential images. The height of domain and the surface potential between octadecyltrichlorosilanes (OTS)-domain and n-(6-aminohexl)aminopropyl-trimethoxysilane (AHAPS)-SAM were about 1.1 nm and -30 mV. These differences of height and surface potential correspond to the ones between OTS and AHAPS. In XPS N 1s spectra, we confirmed the formation of binary SAMs by an amino peak observed at 399.15 eV. The dynamic and the static water contact angles indicated that the wetting property of the binary SAMs was depended on the OTS domain size. In addition, static water contact angles were measured under the conditions of different pH water and zeta-potential also indicated that the electrostatic property of the binary SAMs depended on OTS domain size. Thus, these results showed that the wetting and electrostatic property on the binary SAMs could be regulated by controlling the domain size.

Layer by layer assembly of catalase and amine-terminated ionic liquid onto titanium nitride nanoparticles modified glassy carbon electrode: Study of direct voltammetry and bioelectrocatalytic activity

International Nuclear Information System (INIS)

Saadati, Shagayegh; Salimi, Abdollah; Hallaj, Rahman; Rostami, Amin

2012-01-01

Highlights: ► Catalase and amine-terminated ionic liquid were immobilized to GC/TiNnp with LBL assembly method. ► First a thin layer of NH 2 -IL is covalently attached to GC/TiNnp electrode using electro-oxidation. ► With alternative assemble of IL and catalase with positive and negative charged, multilayer was formed. ► Immobilized catalase shows excellent electrocatalytic activity toward H 2 O 2 reduction. ► Biosensor response is directly correlated to the number of bilayers. - Abstract: A novel, simple and facile layer by layer (LBL) approach is used for modification of glassy carbon (GC) electrode with multilayer of catalase and nanocomposite containing 1-(3-Aminopropyl)-3-methylimidazolium bromide (amine terminated ionic liquid (NH 2 -IL)) and titanium nitride nanoparticles (TiNnp). First a thin layer of NH 2 -IL is covalently attached to GC/TiNnp electrode using electro-oxidation method. Then, with alternative self assemble positively charged NH 2 -IL and negatively charged catalase a sensitive H 2 O 2 biosensor is constructed, whose response is directly correlated to the number of bilayers. The surface coverage of active catalase per bilayer, heterogeneous electron transfer rate constant (k s ) and Michaelis–Menten constant (K M ) of immobilized catalase were 3.32 × 10 −12 mol cm −2 , 5.28 s −1 and 1.1 mM, respectively. The biosensor shows good stability, high reproducibility, long life-time, and fast amperometric response with the high sensitivity of 380 μA mM −1 cm −2 and low detection limit of 100 nM at concentration range up to 2.1 mM.

Information System through ANIS at CeSAM

Science.gov (United States)

Moreau, C.; Agneray, F.; Gimenez, S.

2015-09-01

ANIS (AstroNomical Information System) is a web generic tool developed at CeSAM to facilitate and standardize the implementation of astronomical data of various kinds through private and/or public dedicated Information Systems. The architecture of ANIS is composed of a database server which contains the project data, a web user interface template which provides high level services (search, extract and display imaging and spectroscopic data using a combination of criteria, an object list, a sql query module or a cone search interfaces), a framework composed of several packages, and a metadata database managed by a web administration entity. The process to implement a new ANIS instance at CeSAM is easy and fast : the scientific project has to submit data or a data secure access, the CeSAM team installs the new instance (web interface template and the metadata database), and the project administrator can configure the instance with the web ANIS-administration entity. Currently, the CeSAM offers through ANIS a web access to VO compliant Information Systems for different projects (HeDaM, HST-COSMOS, CFHTLS-ZPhots, ExoDAT,...).

Palladium-catalysed anti-Markovnikov selective oxidative amination

Science.gov (United States)

Kohler, Daniel G.; Gockel, Samuel N.; Kennemur, Jennifer L.; Waller, Peter J.; Hull, Kami L.

2018-03-01

In recent years, the synthesis of amines and other nitrogen-containing motifs has been a major area of research in organic chemistry because they are widely represented in biologically active molecules. Current strategies rely on a multistep approach and require one reactant to be activated prior to the carbon-nitrogen bond formation. This leads to a reaction inefficiency and functional group intolerance. As such, a general approach to the synthesis of nitrogen-containing compounds from readily available and benign starting materials is highly desirable. Here we present a palladium-catalysed oxidative amination reaction in which the addition of the nitrogen occurs at the less-substituted carbon of a double bond, in what is known as anti-Markovnikov selectivity. Alkenes are shown to react with imides in the presence of a palladate catalyst to generate the terminal imide through trans-aminopalladation. Subsequently, olefin isomerization occurs to afford the thermodynamically favoured products. Both the scope of the transformation and mechanistic investigations are reported.

Iridium-Catalyzed Condensation of Primary Amines To Form Secondary Amines

DEFF Research Database (Denmark)

Lorentz-Petersen, Linda Luise Reeh; Jensen, Paw; Madsen, Robert

2009-01-01

Symmetric secondary amines are readily obtained by heating a neat primary amine with 0.5 mol% of bis(dichloro[eta(5)-pentamethylcyclopentadienyl]iridium). The products are isolated by direct distillation in good yields.......Symmetric secondary amines are readily obtained by heating a neat primary amine with 0.5 mol% of bis(dichloro[eta(5)-pentamethylcyclopentadienyl]iridium). The products are isolated by direct distillation in good yields....

78 FR 47695 - Sam Rayburn Dam Power Rate

Science.gov (United States)

2013-08-06

... DEPARTMENT OF ENERGY Southwestern Power Administration Sam Rayburn Dam Power Rate AGENCY: Southwestern Power Administration, DOE. ACTION: Notice of public review and comment. SUMMARY: The current Sam..., Southwestern Power Administration (Southwestern), has prepared Current and Revised 2013 Power Repayment Studies...

Self-assembled monolayers of semi-fluorinated thiols and disulfides with a potentially antibacterial terminal fragment on gold surfaces

International Nuclear Information System (INIS)

Thebault, P.; Taffin de Givenchy, E.; Guittard, F.; Guimon, C.; Geribaldi, S.

2008-01-01

Attempts to elaborate the best organized cationic self-assembled monolayers (SAMs) with sulfur derivatives containing potentially bactericidal quaternary ammonium salt moieties have been performed on gold with the final aim to obtain contact-active antibacterial surfaces. Four molecules bearing two hydrocarbon spacers with different lengths between the sulfur atom and the quaternized nitrogen atom, and two different terminal semi-fluorinated alkyl chains have been synthesised and used in view to evaluate their capacity for leading to the highest densities and the highest organization of potentially active molecules on the metal surface. The formation and quality of SAMs characterized by X-ray photoelectron spectroscopy, Internal Reflexion Infra Red Imaging, contact angle and blocking factor measurements depend on the lengths of both the hydrocarbon spacer and terminal perfluorinated chain

Reactive Landing of Dendrimer Ions onto Activated Self-assembled Monolayer Surfaces

Energy Technology Data Exchange (ETDEWEB)

Hu, Qichi; Laskin, Julia

2014-02-06

The reactivity of gaseous, amine-terminated polyamidoamine (PAMAM) dendrimer ions with activated self-assembled monolayer (SAM) surfaces terminated with N-hydroxysuccinimidyl ester groups (NHS-SAM) is examined using mass-selected ion deposition combined with in situ infrared reflection absorption spectroscopy (IRRAS). The reaction extent is determined from depletion of the infrared band at 1753 cm-1, corresponding to the stretching vibration of the NHS carbonyl groups following ion deposition. For reaction yields below 10%, NHS band depletion follows a linear dependence on the ion dose. By comparing the kinetics plots obtained for 1,12-dodecanediamine and different generations of dendrimer ions (G0–G3) containing 4, 8, 16, and 32 terminal amino group, we demonstrate that the relative reaction efficiency increases linearly with the number of NH2 groups in the molecule. This finding is rationalized assuming the formation of multiple amide bonds upon collision of higher-generation dendrimers with NHS-SAM. Furthermore, by comparing the NHS band depletion following deposition of [M+4H]4+ ions of the G2 dendrimer at 30, 80, and 120 eV, we demonstrate that the ion’s kinetic energy has no measurable effect on reaction efficiency. Similarly, the ion’s charge state only has a minor effect on the reactive landing efficiency of dendrimer ions. Our results indicate that reactive landing is an efficient approach for highly selective covalent immobilization of complex multifunctional molecules onto organic surfaces terminated with labile functional groups.

The N-terminus of amine oxidase of Hansenula polymorpha contains a peroxisomal targeting signal

NARCIS (Netherlands)

Faber, Klaas Nico; Keizer-Gunnink, Ineke; Pluim, Dick; Harder, Willem; AB, Geert; Veenhuis, Marten

1995-01-01

Here we describe the identification of the targeting sequence of peroxisomal amine oxidase (AMO) of H. polymorpha. Deletion analysis revealed that essential targeting information is located within the extreme N-terminal 16 amino acids. Moreover, this sequence can direct a reporter protein to the

Layer by layer assembly of catalase and amine-terminated ionic liquid onto titanium nitride nanoparticles modified glassy carbon electrode: Study of direct voltammetry and bioelectrocatalytic activity

Energy Technology Data Exchange (ETDEWEB)

Saadati, Shagayegh [Department of Chemistry, University of Kurdistan, P.O. Box 416, Sanandaj (Iran, Islamic Republic of); Salimi, Abdollah, E-mail: absalimi@uok.ac.ir [Department of Chemistry, University of Kurdistan, P.O. Box 416, Sanandaj (Iran, Islamic Republic of); Research Center for Nanotechnology, University of Kurdistan, P.O. Box 416, Sanandaj (Iran, Islamic Republic of); Hallaj, Rahman; Rostami, Amin [Department of Chemistry, University of Kurdistan, P.O. Box 416, Sanandaj (Iran, Islamic Republic of)

2012-11-13

Highlights: Black-Right-Pointing-Pointer Catalase and amine-terminated ionic liquid were immobilized to GC/TiNnp with LBL assembly method. Black-Right-Pointing-Pointer First a thin layer of NH{sub 2}-IL is covalently attached to GC/TiNnp electrode using electro-oxidation. Black-Right-Pointing-Pointer With alternative assemble of IL and catalase with positive and negative charged, multilayer was formed. Black-Right-Pointing-Pointer Immobilized catalase shows excellent electrocatalytic activity toward H{sub 2}O{sub 2} reduction. Black-Right-Pointing-Pointer Biosensor response is directly correlated to the number of bilayers. - Abstract: A novel, simple and facile layer by layer (LBL) approach is used for modification of glassy carbon (GC) electrode with multilayer of catalase and nanocomposite containing 1-(3-Aminopropyl)-3-methylimidazolium bromide (amine terminated ionic liquid (NH{sub 2}-IL)) and titanium nitride nanoparticles (TiNnp). First a thin layer of NH{sub 2}-IL is covalently attached to GC/TiNnp electrode using electro-oxidation method. Then, with alternative self assemble positively charged NH{sub 2}-IL and negatively charged catalase a sensitive H{sub 2}O{sub 2} biosensor is constructed, whose response is directly correlated to the number of bilayers. The surface coverage of active catalase per bilayer, heterogeneous electron transfer rate constant (k{sub s}) and Michaelis-Menten constant (K{sub M}) of immobilized catalase were 3.32 Multiplication-Sign 10{sup -12} mol cm{sup -2}, 5.28 s{sup -1} and 1.1 mM, respectively. The biosensor shows good stability, high reproducibility, long life-time, and fast amperometric response with the high sensitivity of 380 {mu}A mM{sup -1} cm{sup -2} and low detection limit of 100 nM at concentration range up to 2.1 mM.

Recent Updates to the System Advisor Model (SAM)

Energy Technology Data Exchange (ETDEWEB)

DiOrio, Nicholas A [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2018-02-14

The System Advisor Model (SAM) is a mature suite of techno-economic models for many renewable energy technologies that can be downloaded for free as a desktop application or software development kit. SAM is used for system-level modeling, including generating performance pro the release of the code as an open source project on GitHub. Other additions that will be covered include the ability to download data directly into SAM from the National Solar Radiation Database (NSRDB) and up- dates to a user-interface macro that assists with PV system sizing. A brief update on SAM's battery model and its integration with the detailed photovoltaic model will also be discussed. Finally, an outline of planned work for the next year will be presented, including the addition of a bifacial model, support for multiple MPPT inputs for detailed inverter modeling, and the addition of a model for inverter thermal behavior.

MICROWAVE-ASSISTED CU (I) CATALYZED SOLVENT-FREE THREE COMPONENT COUPLING OF ALDEHYDE, ALKYNE AND AMINE

Science.gov (United States)

Direct Grignard type addition of terminal alkynes to in situ generated imines, from aldehydes and amines, occurs under microwave irradiation using CuBr alone in a one-pot operation. This solventless approach provides ready access to propargylamines and is applicable both...

A New Structural Form in the SAM/Metal-Dependent O;#8209;Methyltransferase Family: MycE from the Mycinamicin Biosynthetic Pathway

Energy Technology Data Exchange (ETDEWEB)

Akey, David L.; Li, Shengying; Konwerski, Jamie R.; Confer, Laura A.; Bernard, Steffen M.; Anzai, Yojiro; Kato, Fumio; Sherman, David H.; Smith, Janet L. (Michigan); (Toho)

2012-08-01

O-linked methylation of sugar substituents is a common modification in the biosynthesis of many natural products and is catalyzed by multiple families of S-adenosyl-l-methionine (SAM or AdoMet)-dependent methyltransferases (MTs). Mycinamicins, potent antibiotics from Micromonospora griseorubida, can be methylated at two positions on a 6-deoxyallose substituent. The first methylation is catalyzed by MycE, a SAM- and metal-dependent MT. Crystal structures were determined for MycE bound to the product S-adenosyl-l-homocysteine (AdoHcy) and magnesium, both with and without the natural substrate mycinamicin VI. This represents the first structure of a natural product sugar MT in complex with its natural substrate. MycE is a tetramer of a two-domain polypeptide, comprising a C-terminal catalytic MT domain and an N-terminal auxiliary domain, which is important for quaternary assembly and for substrate binding. The symmetric MycE tetramer has a novel MT organization in which each of the four active sites is formed at the junction of three monomers within the tetramer. The active-site structure supports a mechanism in which a conserved histidine acts as a general base, and the metal ion helps to position the methyl acceptor and to stabilize a hydroxylate intermediate. A conserved tyrosine is suggested to support activity through interactions with the transferred methyl group from the SAM methyl donor. The structure of the free enzyme reveals a dramatic order-disorder transition in the active site relative to the S-adenosyl-L-homocysteine complexes, suggesting a mechanism for product/substrate exchange through concerted movement of five loops and the polypeptide C-terminus.

Formation of carboxy- and amide-terminated alkyl monolayers on silicon(111) investigated by ATR-FTIR, XPS, and X-ray scattering: Construction of photoswitchable surfaces

DEFF Research Database (Denmark)

Rück-Braun, Karola; Petersen, Michael Åxman; Michalik, Fabian

2013-01-01

-FTIR and XPS studies of the fulgimide samples revealed closely covered amide-terminated SAMs. Reversible photoswitching of the headgroup was read out by applying XPS, ATR-FTIR, and difference absorption spectra in the mid-IR. In XPS, we observed a reversible breathing of the amide/imide C1s and N1s signals......We have prepared high-quality, densely packed, self-assembled monolayers (SAMs) of carboxy-terminated alkyl chains on Si(111). The samples were made by thermal grafting of methyl undec-10-enoate under an inert atmosphere and subsequent cleavage of the ester functionality to disclose the carboxylic...... zigzag-like substitution pattern for the ester- and carboxy-terminated monolayer. Hydrolysis of the remaining H-Si(111) bonds at the surface furnished HO-Si(111) groups according to XPS and attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR) studies. The amide-terminated alkyl...

Spirit Pluralisme dalam Klenteng Sam Po Kong Semarang

Directory of Open Access Journals (Sweden)

Edi Nurwahyu Julianto

2015-07-01

Full Text Available Klenteng Sam Po Kong has very deep meaning as a symbol of multi cultural; multi ethnic and multi religious. Klenteng Sam Po Kong has a different function, not only used by people with background religious Tri Dharma (Budha, Tao and Konghuchu, but also used by Javanese ethnic with different religious backgrounds. Between ethnic China and Java, mutual respect and tolerance run beliefs and rituals of each. More over, Klenteng Sam Po Kong is a form of pluralism which reflected the fact Sino Javanese Muslim Culture is preserved to date both of sightings physical culture and system cultural in the form of religious rites performed by ethnic China and Java.

Thermal, Catalytic Conversion of Alkanes to Linear Aldehydes and Linear Amines.

Science.gov (United States)

Tang, Xinxin; Jia, Xiangqing; Huang, Zheng

2018-03-21

Alkanes, the main constituents of petroleum, are attractive feedstocks for producing value-added chemicals. Linear aldehydes and amines are two of the most important building blocks in the chemical industry. To date, there have been no effective methods for directly converting n-alkanes to linear aldehydes and linear amines. Here, we report a molecular dual-catalyst system for production of linear aldehydes via regioselective carbonylation of n-alkanes. The system is comprised of a pincer iridium catalyst for transfer-dehydrogenation of the alkane using t-butylethylene or ethylene as a hydrogen acceptor working sequentially with a rhodium catalyst for olefin isomerization-hydroformylation with syngas. The system exhibits high regioselectivity for linear aldehydes and gives high catalytic turnover numbers when using ethylene as the acceptor. In addition, the direct conversion of light alkanes, n-pentane and n-hexane, to siloxy-terminated alkyl aldehydes through a sequence of Ir/Fe-catalyzed alkane silylation and Ir/Rh-catalyzed alkane carbonylation, is described. Finally, the Ir/Rh dual-catalyst strategy has been successfully applied to regioselective alkane aminomethylation to form linear alkyl amines.

Novel bioreducible poly(amido amine)s for highly efficient gene delivery

NARCIS (Netherlands)

Lin, C.; Zhong, Zhiyuan; Lok, Martin C.; Jiang, Xulin; Hennink, Wim E.; Feijen, Jan; Engbersen, Johannes F.J.

2007-01-01

A series of novel bioreducible poly(amido amine)s containing multiple disulfide linkages (SS-PAAs) were synthesized and evaluated as nonviral gene vectors. These linear SS-PAAs could be easily obtained by Michael-type polyaddition of various primary amines to the disulfide-containing cystamine

The spontaneous formation of single-molecule junctions via terminal alkynes

International Nuclear Information System (INIS)

Pla-Vilanova, Pepita; Aragonès, Albert C; Sanz, Fausto; Darwish, Nadim; Diez-Perez, Ismael; Ciampi, Simone

2015-01-01

Herein, we report the spontaneous formation of single-molecule junctions via terminal alkyne contact groups. Self-assembled monolayers that form spontaneously from diluted solutions of 1, 4-diethynylbenzene (DEB) were used to build single-molecule contacts and assessed using the scanning tunneling microscopy-break junction technique (STM-BJ). The STM-BJ technique in both its dynamic and static approaches was used to characterize the lifetime (stability) and the conductivity of a single-DEB wire. It is demonstrated that single-molecule junctions form spontaneously with terminal alkynes and require no electrochemical control or chemical deprotonation. The alkyne anchoring group was compared against typical contact groups exploited in single-molecule studies, i.e. amine (benzenediamine) and thiol (benzendithiol) contact groups. The alkyne contact showed a conductance magnitude comparable to that observed with amine and thiol groups. The lifetime of the junctions formed from alkynes were only slightly less than that of thiols and greater than that observed for amines. These findings are important as (a) they extend the repertoire of chemical contacts used in single-molecule measurements to 1-alkynes, which are synthetically accessible and stable and (b) alkynes have a remarkable affinity toward silicon surfaces, hence opening the door for the study of single-molecule transport on a semiconducting electronic platform. (fast track communication)

Oxyfunctionalization of the Remote C-H Bonds of Aliphatic Amines by Decatungstate Photocatalysis.

Science.gov (United States)

Schultz, Danielle M; Lévesque, François; DiRocco, Daniel A; Reibarkh, Mikhail; Ji, Yining; Joyce, Leo A; Dropinski, James F; Sheng, Huaming; Sherry, Benjamin D; Davies, Ian W

2017-11-27

Aliphatic amines, oxygenated at remote positions within the molecule, represent an important class of synthetic building blocks to which there are currently no direct means of access. Reported herein is an efficient and scalable solution that relies upon decatungstate photocatalysis under acidic conditions using either H 2 O 2 or O 2 as the terminal oxidant. By using these reaction conditions a series of simple and unbiased aliphatic amine starting materials can be oxidized to value-added ketone products. Lastly, NMR spectroscopy using in situ LED-irradiated samples was utilized to monitor the kinetics of the reaction, thus enabling direct translation of the reaction into flow. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Room temperature atomic layerlike deposition of ZnS on organic thin films: Role of substrate functional groups and precursors

Energy Technology Data Exchange (ETDEWEB)

Shi, Zhiwei; Walker, Amy V., E-mail: amy.walker@utdallas.edu [Department of Materials Science and Engineering, University of Texas at Dallas, RL10, 800 W. Campbell Rd., Richardson, Texas 75080 (United States)

2015-09-15

The room temperature atomic layerlike deposition (ALLD) of ZnS on functionalized self-assembled monolayers (SAMs) was investigated, using diethyl zinc (DEZ) and in situ generated H{sub 2}S as reactants. Depositions on SAMs with three different terminal groups, –CH{sub 3,} –OH, and –COOH, were studied. It was found that the reaction of DEZ with the SAM terminal group is critical in determining the film growth rate. Little or no deposition is observed on –CH{sub 3} terminated SAMs because DEZ does not react with the methyl terminal group. ZnS does deposit on both –OH and –COOH terminated SAMs, but the grow rate on –COOH terminated SAMs is ∼10% lower per cycle than on –OH terminated SAMs. DEZ reacts with the hydroxyl group on –OH terminated SAMs, while on –COOH terminated SAMs it reacts with both the hydroxyl and carbonyl bonds of the terminal groups. The carbonyl reaction is found to lead to the formation of ketones rather than deposition of ZnS, lowering the growth rate on –COOH terminated SAMs. SIMS spectra show that both –OH and –COOH terminated SAMs are covered by the deposited ZnS layer after five ALLD cycles. In contrast to ZnO ALLD where the composition of the film differs for the first few layers on –COOH and –OH terminated SAMs, the deposited film composition is the same for both –COOH and –OH terminated SAMs. The deposited film is found to be Zn-rich, suggesting that the reaction of H{sub 2}S with the Zn-surface adduct may be incomplete.

Motor coordination defects in mice deficient for the Sam68 RNA-binding protein.

Science.gov (United States)

Lukong, Kiven E; Richard, Stéphane

2008-06-03

The role of RNA-binding proteins in the central nervous system and more specifically their role in motor coordination and learning are poorly understood. We previously reported that ablation of RNA-binding protein Sam68 in mice results in male sterility and delayed mammary gland development and protection against osteoporosis in females. Sam68 however is highly expressed in most regions of the brain especially the cerebellum and thus we investigated the cerebellar-related manifestations in Sam68-null mice. We analyzed the mice for motor function, sensory function, and learning and memory abilities. Herein, we report that Sam68-null mice have motor coordination defects as assessed by beam walking and rotorod performance. Forty-week-old Sam68-null mice (n=12) were compared to their wild-type littermates (n=12). The Sam68-null mice exhibited more hindpaw faults in beam walking tests and fell from the rotating drum at lower speeds and prematurely compared to the wild-type controls. The Sam68-null mice were, however, normal for forelimb strength, tail-hang reflex, balance test, grid walking, the Morris water task, recognition memory, visual discrimination, auditory stimulation and conditional taste aversion. Our findings support a role for Sam68 in the central nervous system in the regulation of motor coordination.

Radiation streaming with SAM-CE

International Nuclear Information System (INIS)

De Gangi, N.; Cohen, M.O.; Waluschka, E.; Steinberg, H.A.

1980-01-01

The SAM-CE Monte Carlo code has been employed to calculate doses, due to neutron streaming, on the operating floor and other locations of the Millstone Unit II Nuclear Power Facility. Calculated results were compared against measured doses

Selective N-alkylation of amines using nitriles under hydrogenation conditions: facile synthesis of secondary and tertiary amines.

Science.gov (United States)

Ikawa, Takashi; Fujita, Yuki; Mizusaki, Tomoteru; Betsuin, Sae; Takamatsu, Haruki; Maegawa, Tomohiro; Monguchi, Yasunari; Sajiki, Hironao

2012-01-14

Nitriles were found to be highly effective alkylating reagents for the selective N-alkylation of amines under catalytic hydrogenation conditions. For the aromatic primary amines, the corresponding secondary amines were selectively obtained under Pd/C-catalyzed hydrogenation conditions. Although the use of electron poor aromatic amines or bulky nitriles showed a lower reactivity toward the reductive alkylation, the addition of NH(4)OAc enhanced the reactivity to give secondary aromatic amines in good to excellent yields. Under the same reaction conditions, aromatic nitro compounds instead of the aromatic primary amines could be directly transformed into secondary amines via a domino reaction involving the one-pot hydrogenation of the nitro group and the reductive alkylation of the amines. While aliphatic amines were effectively converted to the corresponding tertiary amines under Pd/C-catalyzed conditions, Rh/C was a highly effective catalyst for the N-monoalkylation of aliphatic primary amines without over-alkylation to the tertiary amines. Furthermore, the combination of the Rh/C-catalyzed N-monoalkylation of the aliphatic primary amines and additional Pd/C-catalyzed alkylation of the resulting secondary aliphatic amines could selectively prepare aliphatic tertiary amines possessing three different alkyl groups. According to the mechanistic studies, it seems reasonable to conclude that nitriles were reduced to aldimines before the nucleophilic attack of the amine during the first step of the reaction.

Azobisisobutyronitrile initiated aerobic oxidative transformation of amines: coupling of primary amines and cyanation of tertiary amines.

Science.gov (United States)

Liu, Lianghui; Wang, Zikuan; Fu, Xuefeng; Yan, Chun-Hua

2012-11-16

In the presence of a catalytic amount of radical initiator AIBN, primary amines are oxidatively coupled to imines and tertiary amines are cyanated to α-aminonitriles. These "metal-free" aerobic oxidative coupling reactions may find applications in a wide range of "green" oxidation chemistry.

On LAM's and SAM's for Halley's rotation

Science.gov (United States)

Peale, Stanton J.

1992-01-01

Non principal axis rotation for comet Halley is inferred from dual periodicities evident in the observations. The modes where the spin axis precesses around the axis of minimum moment of inertia (long axis mode or LAM) and where it precesses around the axis of maximum moment of inertia (short axis mode or SAM) are described from an inertial point of view. The currently favored LAM model for Halley's rotation state satisfies observational and dynamical constraints that apparently no SAM can satisfy. But it cannot reproduce the observed post perihelion brightening through seasonal illumination of localized sources on the nucleus, whereas a SAM can easily produce post or pre perihelion brightening by this mechanism. However, the likelihood of a LAM rotation for elongated nuclei of periodic comets such as Halley together with Halley's extreme post perihelion behavior far from the Sun suggest that Halley's post perihelion brightening may be due to effects other than seasonal illumination of localized sources, and therefore such brightening may not constrain its rotation state.

Surface modification of GC and HOPG with diazonium, amine, azide, and olefin derivatives.

Science.gov (United States)

Tanaka, Mutsuo; Sawaguchi, Takahiro; Sato, Yukari; Yoshioka, Kyoko; Niwa, Osamu

2011-01-04

Surface modification of glassy carbon (GC) and highly oriented pyrolytic graphite (HOPG) was carried out with diazonium, amine, azide, and olefin derivatives bearing ferrocene as an electroactive moiety. Features of the modified surfaces were evaluated by surface concentrations of immobilized molecule, blocking effect of the modified surface against redox reaction, and surface observation using cyclic voltammetry and electrochemical scanning tunneling microscope (EC-STM). The measurement of surface concentrations of immobilized molecule revealed the following three aspects: (i) Diazonium and olefin derivatives could modify substrates with the dense-monolayer concentration. (ii) The surface concentration of immobilized amine derivative did not reach to the dense-monolayer concentration reflecting their low reactivity. (iii) The surface modification with the dense-monolayer concentration was also possible with azide derivative, but the modified surface contained some oligomers produced by the photoreaction of azides. Besides, the blocking effect against redox reaction was observed for GC modified with diazonium derivative and for HOPG modified with diazonium and azide derivatives, suggesting fabrication of a densely modified surface. Finally, the surface observation for HOPG modified with diazonium derivative by EC-STM showed a typical monolayer structure, in which the ferrocene moieties were packed densely at random. On the basis of those results, it was demonstrated that surface modification of carbon substrates with diazonium could afford a dense monolayer similar to the self-assembled monolayer (SAM) formation.

Surface adhesion and confinement variation of Staphylococcus aurius on SAM surfaces

Science.gov (United States)

Amroski, Alicia; Olsen, Morgan; Calabrese, Joseph; Senevirathne, Reshani; Senevirathne, Indrajith

2012-02-01

Controlled surface adhesion of non - pathogenic gram positive strain, Staphylococcus aureus is interesting as a model system due to possible development of respective biosensors for prevention and detection of the pathogenic strain methicillin resistant Staphylococcus aureus (MRSA) and further as a study for bio-machine interfacing. Self Assembled Monolayers (SAM) with engineered surfaces of linear thiols on Au(111) were used as the substrate. Sub cultured S. aureus were used for the analysis. The SAM layered surfaces were dipped in 2 -- 4 Log/ml S. aureus solution. Subsequent surface adhesion at different bacterial dilutions on surfaces will be discussed, and correlated with quantitative and qualitative adhesion properties of bacteria on the engineered SAM surfaces. The bacteria adhered SAM surfaces were investigated using intermittent contact, noncontact, lateral force and contact modes of Atomic Force Microscopy (AFM).

Renewing Samsø

DEFF Research Database (Denmark)

Papazu, Irina

2017-01-01

and globally, I ask: if indeed such a process of renewal must be understood as a political process and the island’s energy transition as an inherently political event, what can Samsø teach us about the workings of politics and local democracy as enacted in practice? This is politics not as election result...... or ideological struggle over values, ideals and the distribution of goods, but as the down-to-earth but significant activity of creating something new together....

Identification of trans-acting factors regulating SamDC expression in Oryza sativa

Energy Technology Data Exchange (ETDEWEB)

Basu, Supratim, E-mail: supratim_genetics@yahoo.co.in [Department of Crop Soil and Environmental Sciences, University of Arkansas, Fayetteville, AR 72701 (United States); Division of Plant Biology, Bose Institute, Kolkata (India); Roychoudhury, Aryadeep [Post Graduate Department of Biotechnology, St. Xavier' s College (Autonomous), 30, Mother Teresa Sarani, Kolkata - 700016, West Bengal (India); Sengupta, Dibyendu N. [Division of Plant Biology, Bose Institute, Kolkata (India)

2014-03-07

Highlights: • Identification of cis elements responsible for SamDC expression by in silico analysis. • qPCR analysis of SamDC expression to abiotic and biotic stress treatments. • Detection of SamDC regulators using identified cis-elements as probe by EMSA. • Southwestern Blot analysis to predict the size of the trans-acting factors. - Abstract: Abiotic stress affects the growth and productivity of crop plants; to cope with the adverse environmental conditions, plants have developed efficient defense machinery comprising of antioxidants like phenolics and flavonoids, and osmolytes like polyamines. SamDC is a key enzyme in the polyamine biosynthesis pathway in plants. In our present communication we have done in silico analysis of the promoter region of SamDC to look for the presence of different cis-regulatory elements contributing to its expression. Based on the presence of different cis-regulatory elements we completed comparative analysis of SamDC gene expression in rice lamina of IR-29 and Nonabokra by qPCR in response to the abiotic stress treatments of salinity, drought, cold and the biotic stress treatments of ABA and light. Additionally, to explore the role of the cis-regulatory elements in regulating the expression of SamDC gene in plants we comparatively analyzed the binding of rice nuclear proteins prepared from IR-29 and Nonabokra undergoing various stress treatments. The intensity of the complex formed was low and inducible in IR-29 in contrast to Nonabokra. Southwestern blot analysis helped in predicting the size of the trans-acting factors binding to these cis-elements. To our knowledge this is the first report on the comprehensive analysis of SamDC gene expression in rice and identification of the trans-acting factors regulating its expression.

Unanticipated coordination of tris buffer to the Radical SAM cluster of the RimO methylthiotransferase.

Science.gov (United States)

Molle, Thibaut; Clémancey, Martin; Latour, Jean-Marc; Kathirvelu, Velavan; Sicoli, Giuseppe; Forouhar, Farhad; Mulliez, Etienne; Gambarelli, Serge; Atta, Mohamed

2016-07-01

Radical SAM enzymes generally contain a [4Fe-4S](2+/1+) (RS cluster) cluster bound to the protein via the three cysteines of a canonical motif CxxxCxxC. The non-cysteinyl iron is used to coordinate SAM via its amino-carboxylate moiety. The coordination-induced proximity between the cluster acting as an electron donor and the adenosyl-sulfonium bond of SAM allows for the homolytic cleavage of the latter leading to the formation of the reactive 5'-deoxyadenosyl radical used for substrate activation. Most of the structures of Radical SAM enzymes have been obtained in the presence of SAM, and therefore, little is known about the situation when SAM is not present. In this report, we show that RimO, a methylthiotransferase belonging to the radical SAM superfamily, binds a Tris molecule in the absence of SAM leading to specific spectroscopic signatures both in Mössbauer and pulsed EPR spectroscopies. These data provide a cautionary note for researchers who work with coordinative unsaturated iron sulfur clusters.

Efecto de la polietilenimina en la actividad catalítica de la peroxidasa de rábano (horseradish peroxidase inmovilizada en electrodos de oro modificados con monocapas autoensambladas de tioles (SAMs.

Directory of Open Access Journals (Sweden)

Pedro R. Matheus

2009-05-01

Full Text Available Effect of the Polyethyleneimine in the Activity Catalytic of the horseradish peroxidase Immobilized on Gold Electrodes Modified with a Self-assembled Monolayer of Thiols (SAMs. Studies were conducted bycyclic voltammetry (CV to investigate the effect of the polymer polyethyleneimine (PEI in the electrochemical reversibility of the mediator thionine and thus the catalytic activity of the enzyme horseradish peroxidase of recombinant HRP-NHis (horseradish peroxidase to the has been added to a chain of six histidine in the extreme N-terminal protein. This self produced monolayers of thiols (SAMS on gold electrodes, with chemical modifications obtained through successive stages in the solid phase of the electrode. The gold electrodes were modified with monolayer SAM-TOA-[ANTA/DADOO] -Co2+ [SAM: self-assembled monolayers of thiols, TOA: dithioctic acid, ANTA: nitrilotriacetic acid, DADOO: 1,8-diamino-3,6-dioxa octane]. The results showed that the presence of the polymer improves the electrochemical reversibility of the mediator to endure catalyticcurrents as high as those that are obtained with molar ratios ANTA:DADOO 10:1 in the absence of PEI, and improve the response voltammetric obtained.

Development of chiral terminal-alkene-phosphine hybrid ligands for palladium-catalyzed asymmetric allylic substitutions.

Science.gov (United States)

Liu, Zhaoqun; Du, Haifeng

2010-07-02

A variety of novel chiral terminal-alkene-phosphine hybrid ligands were successfully developed from diethyl L-tartrate for palladium-catalyzed asymmetric allylic alkylations, etherifications, and amination to give the desired products in excellent yields and ee's.

The rate of charge tunneling is insensitive to polar terminal groups in self-assembled monolayers in Ag(TS)S(CH2)(n)M(CH2)(m)T//Ga2O3/EGaIn junctions.

Science.gov (United States)

Yoon, Hyo Jae; Bowers, Carleen M; Baghbanzadeh, Mostafa; Whitesides, George M

2014-01-08

This paper describes a physical-organic study of the effect of uncharged, polar, functional groups on the rate of charge transport by tunneling across self-assembled monolayer (SAM)-based large-area junctions of the form Ag(TS)S(CH2)(n)M(CH2)(m)T//Ga2O3/EGaIn. Here Ag(TS) is a template-stripped silver substrate, -M- and -T are "middle" and "terminal" functional groups, and EGaIn is eutectic gallium-indium alloy. Twelve uncharged polar groups (-T = CN, CO2CH3, CF3, OCH3, N(CH3)2, CON(CH3)2, SCH3, SO2CH3, Br, P(O)(OEt)2, NHCOCH3, OSi(OCH3)3), having permanent dipole moments in the range 0.5 < μ < 4.5, were incorporated into the SAM. A comparison of the electrical characteristics of these junctions with those of junctions formed from n-alkanethiolates led to the conclusion that the rates of charge tunneling are insensitive to the replacement of terminal alkyl groups with the terminal polar groups in this set. The current densities measured in this work suggest that the tunneling decay parameter and injection current for SAMs terminated in nonpolar n-alkyl groups, and polar groups selected from common polar organic groups, are statistically indistinguishable.

Bioreducible poly(amido amine)s for non-viral gene delivery

NARCIS (Netherlands)

Lin, C.

2008-01-01

This thesis describes the design and development of bioreducible poly(amido amine)s as non-viral vectors for gene delivery in vitro and in vivo. The structural influences of these polymers on their physico-chemical properties and gene delivery properties, transfection capability and cytotoxicity in

Study of radiation effects on the senescence accelerated mouse (SAM), 1

International Nuclear Information System (INIS)

Kishikawa, Masao; Iseki, Masachika; Kondo, Hisayoshi

1989-01-01

The study of age-related changes in the central nervous system due to irradiation is being carried out in our laboratory. The senescence accelerated mouse (SAM P/1, male) was used for this investigation concerning the one-trial passive avoidance reaction. The experimental group of SAM P/1 was irradiated with 4 Gy at 8 weeks old, and passive avoidance reaction (PAR) was measured for 180 seconds as a learning task. At the age of 7 months, statistical analysis of PAR was conducted using the life time analysis method. The passive avoidance reaction of the irradiated group was more impaired than that of the control group. The results of this investigation suggested that the learning and/or memory disturbance of irradiated SAM P/1 is similar to the changes of more aged SAM P/1. (author)

CareSam

DEFF Research Database (Denmark)

Liveng, Anne; Christensen, Jonas

2016-01-01

negative cultural perceptions of help-needing elderly and the people who support them in everyday life? In answering these questions and thereby reflecting on our own work process we apply a caring, a learning and a political perspective. Hereby the article wishes to formulate a methodological point...... to maintain immediately conflicting dimensions in this kind of work.......This article presents findings and discussions generated on the basis of the Danish-Swedish development project CareSam. The article will on the one hand focus on how work in groups consisting of representatives from different levels in the elderly care sector at one time served as learning spaces...

Fate and transformation products of amine-terminated PAMAM dendrimers under ozonation and irradiation

International Nuclear Information System (INIS)

Santiago-Morales, Javier; Rosal, Roberto; Hernando, María D.; Ulaszewska, Maria M.; García-Calvo, Eloy; Fernández-Alba, Amadeo R.

2014-01-01

Highlights: • We detected transformation products from dendrimer under ozonation and irradiation. • Retro-Michael fragmentation pathway with highly oxygenated structures. • High toxicity of G3 PAMAM dendrimer for green algae. • Reactive oxygen species were associated with the toxic damage. • Transformation mixtures could be more toxic than the parent dendrimer. -- Abstract: This article deals with the degradation of a third-generation (G3) poly(amidoamine) (PAMAM) dendrimer under ozonation and irradiation. The identification and quantification of G3 PAMAM dendrimer and its transformation products has been performed by liquid chromatography–electrospray ionization-hybrid quadrupole time-of-flight-mass spectrometry. The dendrimer was completely depleted by ozone in less than 1 min. The effect of ultraviolet irradiation was attributed to hydroxyl-mediated oxidation. The transformation products were attributed to the oxidation of amines, which resulted in highly oxidized structures with abundance of carboxylic acids, which started from the formation of amine oxide and the scission of the C-N bond of the amide group. We studied the toxicity of treated mixtures for six different organisms: the acute toxicity for the bacterium Vibrio fischeri and the microcrustacean Daphnia magna, the multigenerational growth inhibition of the alga Pseudokirchneriella subcapitata, and the seed germination phytotoxicity of Licopersicon esculentum, Lactuca sativa and Lolium perenne. Ozonation and irradiation originated transformation products are more toxic than the parent dendrimer. The toxicity of the dendrimer for the green alga was linked to a strong increase of intracellular reactive oxygen species with intense lipid peroxidation

Fate and transformation products of amine-terminated PAMAM dendrimers under ozonation and irradiation

Energy Technology Data Exchange (ETDEWEB)

Santiago-Morales, Javier [Department of Chemical Engineering, University of Alcalá, 28871 Alcalá de Henares, Madrid (Spain); Rosal, Roberto, E-mail: roberto.rosal@uah.es [Department of Chemical Engineering, University of Alcalá, 28871 Alcalá de Henares, Madrid (Spain); Advanced Study Institute of Madrid, IMDEA Agua, Parque Científico Tecnológico, 28805 Alcalá de Henares, Madrid (Spain); Hernando, María D. [Spanish National Institute for Agricultural and Food Research and Technology – INIA, Crta. de la Coruña, km 7.5, 28040 Madrid (Spain); Ulaszewska, Maria M. [Advanced Study Institute of Madrid, IMDEA Agua, Parque Científico Tecnológico, 28805 Alcalá de Henares, Madrid (Spain); García-Calvo, Eloy [Department of Chemical Engineering, University of Alcalá, 28871 Alcalá de Henares, Madrid (Spain); Advanced Study Institute of Madrid, IMDEA Agua, Parque Científico Tecnológico, 28805 Alcalá de Henares, Madrid (Spain); Fernández-Alba, Amadeo R. [Advanced Study Institute of Madrid, IMDEA Agua, Parque Científico Tecnológico, 28805 Alcalá de Henares, Madrid (Spain); Pesticide Residue Research Group, Department of Hydrogeology and Analytical Chemistry, University of Almería, 04120 Almería (Spain)

2014-02-15

Highlights: • We detected transformation products from dendrimer under ozonation and irradiation. • Retro-Michael fragmentation pathway with highly oxygenated structures. • High toxicity of G3 PAMAM dendrimer for green algae. • Reactive oxygen species were associated with the toxic damage. • Transformation mixtures could be more toxic than the parent dendrimer. -- Abstract: This article deals with the degradation of a third-generation (G3) poly(amidoamine) (PAMAM) dendrimer under ozonation and irradiation. The identification and quantification of G3 PAMAM dendrimer and its transformation products has been performed by liquid chromatography–electrospray ionization-hybrid quadrupole time-of-flight-mass spectrometry. The dendrimer was completely depleted by ozone in less than 1 min. The effect of ultraviolet irradiation was attributed to hydroxyl-mediated oxidation. The transformation products were attributed to the oxidation of amines, which resulted in highly oxidized structures with abundance of carboxylic acids, which started from the formation of amine oxide and the scission of the C-N bond of the amide group. We studied the toxicity of treated mixtures for six different organisms: the acute toxicity for the bacterium Vibrio fischeri and the microcrustacean Daphnia magna, the multigenerational growth inhibition of the alga Pseudokirchneriella subcapitata, and the seed germination phytotoxicity of Licopersicon esculentum, Lactuca sativa and Lolium perenne. Ozonation and irradiation originated transformation products are more toxic than the parent dendrimer. The toxicity of the dendrimer for the green alga was linked to a strong increase of intracellular reactive oxygen species with intense lipid peroxidation.

Tandem Carbocupration/Oxygenation of Terminal Alkynes

Science.gov (United States)

Zhang, Donghui; Ready, Joseph M.

2008-01-01

A direct and general synthesis of α-branched aldehydes and their enol derivatives is described. Carbocupration of terminal alkynes and subsequent oxygenation with lithium tert-butyl peroxide generates a metallo-enolate. Trapping with various electrophiles provides α-branched aldehydes or stereo-defined trisubstituted enol esters or silyl ethers. The tandem carbocupration/oxygenation tolerates alkyl and silyl ethers, esters and tertiary amines. The reaction is effective with organocopper complexes derived from primary, secondary and tertiary Grignard reagents and from n-butyllithium. PMID:16321021

The SAMS: Smartphone Addiction Management System and verification.

Science.gov (United States)

Lee, Heyoung; Ahn, Heejune; Choi, Samwook; Choi, Wanbok

2014-01-01

While the popularity of smartphones has given enormous convenience to our lives, their pathological use has created a new mental health concern among the community. Hence, intensive research is being conducted on the etiology and treatment of the condition. However, the traditional clinical approach based surveys and interviews has serious limitations: health professionals cannot perform continual assessment and intervention for the affected group and the subjectivity of assessment is questionable. To cope with these limitations, a comprehensive ICT (Information and Communications Technology) system called SAMS (Smartphone Addiction Management System) is developed for objective assessment and intervention. The SAMS system consists of an Android smartphone application and a web application server. The SAMS client monitors the user's application usage together with GPS location and Internet access location, and transmits the data to the SAMS server. The SAMS server stores the usage data and performs key statistical data analysis and usage intervention according to the clinicians' decision. To verify the reliability and efficacy of the developed system, a comparison study with survey-based screening with the K-SAS (Korean Smartphone Addiction Scale) as well as self-field trials is performed. The comparison study is done using usage data from 14 users who are 19 to 50 year old adults that left at least 1 week usage logs and completed the survey questionnaires. The field trial fully verified the accuracy of the time, location, and Internet access information in the usage measurement and the reliability of the system operation over more than 2 weeks. The comparison study showed that daily use count has a strong correlation with K-SAS scores, whereas daily use times do not strongly correlate for potentially addicted users. The correlation coefficients of count and times with total K-SAS score are CC = 0.62 and CC =0.07, respectively, and the t-test analysis for the

The economics of amine usage

International Nuclear Information System (INIS)

Fountain, M.J.

1994-01-01

The EPRI computer programm, 'Aminemod', a PWR chemistry model, has been used to compare the technical advantages of the 'advanced' amines, ethanolamine, 1,2 diaminoethane and 5 aminopentanol over morpholine in generating an elevated pH in the moisture separator and the economics of using these amines has been assessed by using an MS Excel spreadsheet in conjunction with Aminemod. The advanced amines are capable of achieving 1 pH unit above neutrality, the EPRI target for prevention of erosion-corrison, at acceptable cost and, compared with 'conventional' amines, at considerably reduced ionic load on the condensate polisher. The exercise demonstrates that it is essential to evaluate the effect of an amine dosing regime on the total operating cost and that it is not possible to prejudge the economic outcome on the basis of an amine's purchase price. (orig.)

Automated one-loop calculations with GoSam

International Nuclear Information System (INIS)

Cullen, Gavin; Greiner, Nicolas; Heinrich, Gudrun; Reiter, Thomas; Luisoni, Gionata; Mastrolia, Pierpaolo; Ossola, Giovanni; Tramontano, Francesco

2012-01-01

We present the program package GoSam which is designed for the automated calculation of one-loop amplitudes for multi-particle processes in renormalisable quantum field theories. The amplitudes, which are generated in terms of Feynman diagrams, can be reduced using either D-dimensional integrand-level decomposition or tensor reduction. GoSam can be used to calculate one-loop QCD and/or electroweak corrections to Standard Model processes and offers the flexibility to link model files for theories Beyond the Standard Model. A standard interface to programs calculating real radiation is also implemented. We demonstrate the flexibility of the program by presenting examples of processes with up to six external legs attached to the loop. (orig.)

Automated One-Loop Calculations with GoSam

CERN Document Server

Cullen, Gavin; Heinrich, Gudrun; Luisoni, Gionata; Mastrolia, Pierpaolo; Ossola, Giovanni; Reiter, Thomas; Tramontano, Francesco

2012-01-01

We present the program package GoSam which is designed for the automated calculation of one-loop amplitudes for multi-particle processes in renormalisable quantum field theories. The amplitudes, which are generated in terms of Feynman diagrams, can be reduced using either D-dimensional integrand-level decomposition or tensor reduction. GoSam can be used to calculate one-loop QCD and/or electroweak corrections to Standard Model processes and offers the flexibility to link model files for theories Beyond the Standard Model. A standard interface to programs calculating real radiation is also implemented. We demonstrate the flexibility of the program by presenting examples of processes with up to six external legs attached to the loop.

Teleconnection stationarity, variability and trends of the Southern Annular Mode (SAM) during the last millennium

Science.gov (United States)

Dätwyler, Christoph; Neukom, Raphael; Abram, Nerilie J.; Gallant, Ailie J. E.; Grosjean, Martin; Jacques-Coper, Martín; Karoly, David J.; Villalba, Ricardo

2017-11-01

The Southern Annular Mode (SAM) is the leading mode of atmospheric interannual variability in the Southern Hemisphere (SH) extra-tropics. Here, we assess the stationarity of SAM spatial correlations with instrumental and paleoclimate proxy data for the past millennium. The instrumental period shows that temporal non-stationarities in SAM teleconnections are not consistent across the SH land areas. This suggests that the influence of the SAM index is modulated by regional effects. However, within key-regions with good proxy data coverage (South America, Tasmania, New Zealand), teleconnections are mostly stationary over the instrumental period. Using different stationarity criteria for proxy record selection, we provide new austral summer and annual mean SAM index reconstructions over the last millennium. Our summer SAM reconstructions are very robust to changes in proxy record selection and the selection of the calibration period, particularly on the multi-decadal timescale. In contrast, the weaker performance and lower agreement in the annual mean SAM reconstructions point towards changing teleconnection patterns that may be particularly important outside the summer months. Our results clearly portend that the temporal stationarity of the proxy-climate relationships should be taken into account in the design of comprehensive regional and hemispherical climate reconstructions. The summer SAM reconstructions show no significant relationship to solar, greenhouse gas and volcanic forcing, with the exception of an extremely strong negative anomaly following the AD 1257 Samalas eruption. Furthermore, reconstructed pre-industrial summer SAM trends are very similar to trends obtained by model control simulations. We find that recent trends in the summer SAM lie outside the 5-95% range of pre-industrial natural variability.

Bacterial degradation of monocyclic aromatic amines

Directory of Open Access Journals (Sweden)

Pankaj Kumar Arora

2015-08-01

Full Text Available Aromatic amines are an important group of industrial chemicals, which are widely used for manufacturing of dyes, pesticides, drugs, pigments, and other industrial products. These compounds have been considered highly toxic to human beings due to their carcinogenic nature. Three groups of aromatic amines have been recognized: monocyclic, polycyclic and heterocyclic aromatic amines. Bacterial degradation of several monocyclic aromatic compounds has been studied in a variety of bacteria, which utilizes monocyclic aromatic amines as their sole source of carbon and energy. Several degradation pathways have been proposed and the related enzymes and genes have also been characterized. Many reviews have been reviewed toxicity of monocyclic aromatic amines; however, there is lack of review on biodegradation of monocyclic aromatic amines. The aim of this review is to summarize bacterial degradation of monocyclic aromatic amines. This review will increase our current understanding of biochemical and molecular basis of bacterial degradation of monocyclic aromatic amines.

Amine Measurements in Boreal Forest Air

Science.gov (United States)

Hemmilä, Marja; Hellén, Heidi; Makkonen, Ulla; Hakola, Hannele

2015-04-01

Amines are reactive, volatile bases in the air with a general formula of RNH2, R2NH or R3N. Especially small amines can stabilize sulphuric acid clusters and hence affect nucleation. Amines react rapidly with hydroxyl radical (OH˙) thus affecting oxidative capacity of the atmosphere. The amine concentrations are higher in forest air than in urban air (Hellén et al., 2014), but the sources are not known. In order to get more information concerning amine sources, we conducted a measurement campaign in a boreal forest. At SMEAR II station at Hyytiälä, Southern Finland (61°510'N, 24°170'E, 180 m a.s.l.) The measurements cover seven months, from June to December 2014. For sampling and measuring we used MARGA (The instrument for Measuring AeRosols and Gases in Ambient air) which is an on-line ion chromatograph (IC) connected to a sampling system. The IC component of the MARGA system was coupled to an electrospray ionization quadrupole mass spectrometer (MS) to improve sensitivity of amine measurements. This new set-up enabled amine concentration measurements in ambient air both in aerosol and gas phases with a time resolution of only 1 hour. With MARGA-MS we analysed 7 different amines: monomethylamine (MMA), dimethylamine (DMA), trimethylamine (TMA), ethylamine (EA), diethylamine (DEA), propylamine (PA) and butylamine (BA). In preliminary data-analysis we found out, that in June and July most of the measured amines were in gas phase, and particle phase amine concentrations were mostly under detection limits (<1.7 pptv). In June the gaseous amine concentrations were higher than in July. The measured concentrations of gaseous amines followed temperature variation, which could indicate that amines are produced and emitted from the environment or re-emitted from the surfaces as temperature rises after deposition during night-time. All measured amines had similar diurnal variation with maxima during afternoon and minima during night. Results from other months will also

SAMS: The synchronization and monitoring system for ATF [Advanced Toroidal Facility] data acquisition

International Nuclear Information System (INIS)

Greenwood, D.E.

1987-01-01

SAMS performs much of the synchronization of the distributed data acquisition system for the Advanced Toroidal Facility (ATF). SAMS is responsible for propagating shot information and managing te data system directories and logical names. This paper describes how SAMS communicates with other processes, both within the VAX cluster that supports most of the ATF data acquisition and on VAXes that are connected to the cluster via DECnet. 3 refs

Benchmark Simulation of Natural Circulation Cooling System with Salt Working Fluid Using SAM

Energy Technology Data Exchange (ETDEWEB)

Ahmed, K. K.; Scarlat, R. O.; Hu, R.

2017-09-03

Liquid salt-cooled reactors, such as the Fluoride Salt-Cooled High-Temperature Reactor (FHR), offer passive decay heat removal through natural circulation using Direct Reactor Auxiliary Cooling System (DRACS) loops. The behavior of such systems should be well-understood through performance analysis. The advanced system thermal-hydraulics tool System Analysis Module (SAM) from Argonne National Laboratory has been selected for this purpose. The work presented here is part of a larger study in which SAM modeling capabilities are being enhanced for the system analyses of FHR or Molten Salt Reactors (MSR). Liquid salt thermophysical properties have been implemented in SAM, as well as properties of Dowtherm A, which is used as a simulant fluid for scaled experiments, for future code validation studies. Additional physics modules to represent phenomena specific to salt-cooled reactors, such as freezing of coolant, are being implemented in SAM. This study presents a useful first benchmark for the applicability of SAM to liquid salt-cooled reactors: it provides steady-state and transient comparisons for a salt reactor system. A RELAP5-3D model of the Mark-1 Pebble-Bed FHR (Mk1 PB-FHR), and in particular its DRACS loop for emergency heat removal, provides steady state and transient results for flow rates and temperatures in the system that are used here for code-to-code comparison with SAM. The transient studied is a loss of forced circulation with SCRAM event. To the knowledge of the authors, this is the first application of SAM to FHR or any other molten salt reactors. While building these models in SAM, any gaps in the code’s capability to simulate such systems are identified and addressed immediately, or listed as future improvements to the code.

Bringing a Chemical Laboratory Named Sam to Mars on the 2011 Curiosity Rover

Science.gov (United States)

Mahaffy, P. R.; Bleacher, L.; Jones, A.; Atreya, S. K.; Manning, H. L.; Cabane, M.; Webster, C. R.; Sam Team

2010-12-01

Introduction: An important goal of upcoming missions to Mars is to understand if life could have developed there. The task of the Sample Analysis at Mars (SAM) suite of instruments [1] and the other Curiosity investigations [2] is to move us steadily toward that goal with an assessment of the habitability of our neighboring planet through a series of chemical and geological measurements. SAM is designed to search for organic compounds and inorganic volatiles and measure isotope ratios. Other instruments on Curiosity will provide elemental analysis and identify minerals. SAM will analyze both atmospheric samples and gases evolved from powdered rocks that may have formed billions of years ago with Curiosity providing access to interesting sites scouted by orbiting cameras and spectrometers. SAM Instrument Suite: SAM’s instruments are a Quadrupole Mass Spectrometer (QMS), a 6-column Gas Chromatograph (GC), and a 2-channel Tunable Laser Spectrometer (TLS). SAM can identify organic compounds in Mars rocks to sub-ppb sensitivity and secure precise isotope ratios for C, H, and O in carbon dioxide and water and measure trace levels of methane and its carbon 13 isotope. The SAM gas processing system consists of valves, heaters, pressure sensors, gas scrubbers and getters, traps, and gas tanks used for calibration or combustion experiments [2]. A variety of calibrant compounds interior and exterior to SAM will allow the science and engineering teams to assess SAM’s performance. SAM has been calibrated and tested in a Mars-like environment. Keeping Educators and the Public Informed: The Education and Public Outreach (EPO) goals of the SAM team are to make this complex chemical laboratory and its data widely available to educators, students, and the public. Formal education activities include developing templates for professional development workshops for educators to teach them about SAM and Curiosity, incorporating data into Mars Student Data Teams, and writing articles

A classification model of Hyperion image base on SAM combined decision tree

Science.gov (United States)

Wang, Zhenghai; Hu, Guangdao; Zhou, YongZhang; Liu, Xin

2009-10-01

Monitoring the Earth using imaging spectrometers has necessitated more accurate analyses and new applications to remote sensing. A very high dimensional input space requires an exponentially large amount of data to adequately and reliably represent the classes in that space. On the other hand, with increase in the input dimensionality the hypothesis space grows exponentially, which makes the classification performance highly unreliable. Traditional classification algorithms Classification of hyperspectral images is challenging. New algorithms have to be developed for hyperspectral data classification. The Spectral Angle Mapper (SAM) is a physically-based spectral classification that uses an ndimensional angle to match pixels to reference spectra. The algorithm determines the spectral similarity between two spectra by calculating the angle between the spectra, treating them as vectors in a space with dimensionality equal to the number of bands. The key and difficulty is that we should artificial defining the threshold of SAM. The classification precision depends on the rationality of the threshold of SAM. In order to resolve this problem, this paper proposes a new automatic classification model of remote sensing image using SAM combined with decision tree. It can automatic choose the appropriate threshold of SAM and improve the classify precision of SAM base on the analyze of field spectrum. The test area located in Heqing Yunnan was imaged by EO_1 Hyperion imaging spectrometer using 224 bands in visual and near infrared. The area included limestone areas, rock fields, soil and forests. The area was classified into four different vegetation and soil types. The results show that this method choose the appropriate threshold of SAM and eliminates the disturbance and influence of unwanted objects effectively, so as to improve the classification precision. Compared with the likelihood classification by field survey data, the classification precision of this model

Quality Control Guidelines for SAM Biotoxin Methods

Science.gov (United States)

Learn more about quality control guidelines and recommendations for the analysis of samples using the pathogen methods listed in EPA's Selected Analytical Methods for Environmental Remediation and Recovery (SAM).

Quality Control Guidelines for SAM Radiochemical Methods

Science.gov (United States)

Learn more about quality control guidelines and recommendations for the analysis of samples using the radiochemistry methods listed in EPA's Selected Analytical Methods for Environmental Remediation and Recovery (SAM).

Quality Control Guidelines for SAM Pathogen Methods

Science.gov (United States)

Learn more about quality control guidelines and recommendations for the analysis of samples using the biotoxin methods listed in EPA's Selected Analytical Methods for Environmental Remediation and Recovery (SAM).

Quality Control Guidelines for SAM Chemical Methods

Science.gov (United States)

Learn more about quality control guidelines and recommendations for the analysis of samples using the chemistry methods listed in EPA's Selected Analytical Methods for Environmental Remediation and Recovery (SAM).

Ancillary ligand-free copper catalysed hydrohydrazination of terminal alkynes with NH2NH2.

Science.gov (United States)

Peltier, Jesse L; Jazzar, Rodolphe; Melaimi, Mohand; Bertrand, Guy

2016-02-14

An efficient and selective Cu-catalysed hydrohydrazination of terminal alkynes with parent hydrazine is reported. The methodology tolerates a broad range of functional groups, allows for the synthesis of symmetrical and unsymmetrical azines, and can be extended to hydrazine derivatives and amines.

Combined atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and quartz crystal microbalance (QCM) studies of glucose oxidase (GOx) immobilised onto self-assembled monolayer on the gold film

International Nuclear Information System (INIS)

Losic, D.; Shapter, J.; Gooding, J.; Erokin, P.; Short, K.

1999-01-01

In fabrication of biosensors, self-assembled monolayers (SAM) are an attractive method of immobilising enzymes at electrode surface since it allows precise control over the amount and spatial distribution of the immobilized enzyme. The covalent attachment of glucose oxidase (GOx) to a carboxylic terminated SAM chemisorbed onto gold films was achieved via carbodiimide activation of the carboxylic acids to a reactive intermediate susceptible to nucleophilic attack by amines on free lysine chains of the enzyme. Atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and quartz crystal microbalance (QCM) measurements were used for characterisation of GOx modified gold surfaces. Tapping mode AFM studies have revealed that GOx molecules form slightly disordered arrays of pentagonal or hexagonal clusters. Observed features of immobilised GOx are distributed as a submonolayer on the SAM surface which has allowed visualisation of native and unfolded enzyme structure. The presence of the SAM and enzyme on the gold surface was detected by XPS spectroscopy. Spectra show typical peaks for the C 1s, O 1s and N 1s regions. A kinetic study of the adsorption of GOx onto activated SAM using in-situ QCM allowed determination the amount of immobilised GOx on the layer and consequently the optimal immobilisation conditions. Performance parameters of the biosensor such as sensitivity to glucose concentration as a function of enzyme loading were evaluated amperometrically using the redox mediator p-benzoquinone

Data handling with SAM and art at the NOνA experiment

International Nuclear Information System (INIS)

Aurisano, A; Backhouse, C; Davies, G S; Illingworth, R; Mengel, M; Norman, A; Mayer, N; Rocco, D; Zirnstein, J

2015-01-01

During operations, NOvA produces between 5,000 and 7,000 raw files per day with peaks in excess of 12,000. These files must be processed in several stages to produce fully calibrated and reconstructed analysis files. In addition, many simulated neutrino interactions must be produced and processed through the same stages as data. To accommodate the large volume of data and Monte Carlo, production must be possible both on the Fermilab grid and on off-site farms, such as the ones accessible through the Open Science Grid. To handle the challenge of cataloging these files and to facilitate their off-line processing, we have adopted the SAM system developed at Fermilab. SAM indexes files according to metadata, keeps track of each file's physical locations, provides dataset management facilities, and facilitates data transfer to off-site grids. To integrate SAM with Fermilab's art software framework and the NOvA production workflow, we have developed methods to embed metadata into our configuration files, art files, and standalone ROOT files. A module in the art framework propagates the embedded information from configuration files into art files, and from input art files to output art files, allowing us to maintain a complete processing history within our files. Embedding metadata in configuration files also allows configuration files indexed in SAM to be used as inputs to Monte Carlo production jobs. Further, SAM keeps track of the input files used to create each output file. Parentage information enables the construction of self-draining datasets which have become the primary production paradigm used at NOvA. In this paper we will present an overview of SAM at NOvA and how it has transformed the file production framework used by the experiment. (paper)

Winning Attitude & Dedication to Physical Therapy Keep Sam Schmidt on Track

Science.gov (United States)

Bosley, Nikki Prevenslik

2006-01-01

This article relates how Sam Schmidt returned to living a productive life after an accident left him with spinal cord injury. Schmidt was a former Indy Racing League driver who founded Sam Schmidt Motorsports after his accident in 2000. Schmidt's car hit the wall as he exited turn two during a practice session at Walt Disney World Speedway in…

Technoeconomic Modeling of Battery Energy Storage in SAM

Energy Technology Data Exchange (ETDEWEB)

DiOrio, Nicholas [National Renewable Energy Lab. (NREL), Golden, CO (United States); Dobos, Aron [National Renewable Energy Lab. (NREL), Golden, CO (United States); Janzou, Steven [National Renewable Energy Lab. (NREL), Golden, CO (United States); Nelson, Austin [National Renewable Energy Lab. (NREL), Golden, CO (United States); Lundstrom, Blake [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2015-09-01

Detailed comprehensive lead-acid and lithium-ion battery models have been integrated with photovoltaic models in an effort to allow System Advisor Model (SAM) to offer the ability to predict the performance and economic benefit of behind the meter storage. In a system with storage, excess PV energy can be saved until later in the day when PV production has fallen, or until times of peak demand when it is more valuable. Complex dispatch strategies can be developed to leverage storage to reduce energy consumption or power demand based on the utility rate structure. This document describes the details of the battery performance and economic models in SAM.

Experimental and computational investigation of graphene/SAMs/n-Si Schottky diodes

Science.gov (United States)

Aydin, H.; Bacaksiz, C.; Yagmurcukardes, N.; Karakaya, C.; Mermer, O.; Can, M.; Senger, R. T.; Sahin, H.; Selamet, Y.

2018-01-01

We have investigated the effect of two different self-assembled monolayers (SAMs) on electrical characteristics of bilayer graphene (BLG)/n-Si Schottky diodes. Novel 4″bis(diphenylamino)-1, 1‧:3″-terphenyl-5‧ carboxylic acids (TPA) and 4,4-di-9H-carbazol-9-yl-1,1‧:3‧1‧-terphenyl-5‧ carboxylic acid (CAR) aromatic SAMs have been used to modify n-Si surfaces. Cyclic voltammetry (CV) and Kelvin probe force microscopy (KPFM) results have been evaluated to verify the modification of n-Si surface. The current-voltage (I-V) characteristics of bare and SAMs modified devices show rectification behaviour verifying a Schottky junction at the interface. The ideality factors (n) from ln(I)-V dependences were determined as 2.13, 1.96 and 2.07 for BLG/n-Si, BLG/TPA/n-Si and BLG/CAR/n-Si Schottky diodes, respectively. In addition, Schottky barrier height (SBH) and series resistance (Rs) of SAMs modified diodes were decreased compared to bare diode due to the formation of a compatible interface between graphene and Si as well as π-π interaction between aromatic SAMs and graphene. The CAR-based device exhibits better diode characteristic compared to the TPA-based device. Computational simulations show that the BLG/CAR system exhibits smaller energy-level-differences than the BLG/TPA, which supports the experimental findings of a lower Schottky barrier and series resistance in BLG/CAR diode.

The impact of aminated surface ligands and silica shells on the stability, uptake, and toxicity of engineered silver nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Bonventre, Josephine A.; Pryor, Joseph B.; Harper, Bryan J.; Harper, Stacey L., E-mail: stacey.harper@oregonstate.edu [Oregon State University, Department of Environmental and Molecular Toxicology (United States)

2014-12-15

Inherent nanomaterial characteristics, composition, surface chemistry, and primary particle size, are known to impact particle stability, uptake, and toxicity. Nanocomposites challenge our ability to predict nanoparticle reactivity in biological systems if they are composed of materials with contrasting relative toxicities. We hypothesized that toxicity would be dominated by the nanoparticle surface (shell vs core), and that modulating the surface ligands would have a direct impact on uptake. We exposed developing zebrafish (Danio rerio) to a series of ∼70 nm amine-terminated silver nanoparticles with silica shells (AgSi NPs) to investigate the relative influence of surface amination, composition, and size on toxicity. Like-sized aminated AgSi and Si NPs were more toxic than paired hydroxyl-terminated nanoparticles; however, both AgSi NPs were more toxic than the Si NPs, indicating a significant contribution of the silver core to the toxicity. Incremental increases in surface amination did not linearly increase uptake and toxicity, but did have a marked impact on dispersion stability. Mass-based exposure metrics initially supported the hypothesis that smaller nanoparticles (20 nm) would be more toxic than larger particles (70 nm). However, surface area-based metrics revealed that toxicity was independent of size. Our studies suggest that nanoparticle surfaces play a critical role in the uptake and toxicity of AgSi NPs, while the impact of size may be a function of the exposure metric used. Overall, uptake and toxicity can be dramatically altered by small changes in surface functionalization or exposure media. Only after understanding the magnitude of these changes, can we begin to understand the biologically available dose following nanoparticle exposure.

Sam Wagstaffi unustatud kired / Ahto Külvet

Index Scriptorium Estoniae

Külvet, Ahto

2008-01-01

Dokumentaalfilm "Black, White & Gray: Sam Wagstaff and Robert Mapplethorpe" : autor ja režissöör James Crump : Ameerika Ühendriigid 2007. Filmi näidati filminädala "Art in America" raames Tallinnas

Highly enantioselective catalytic cross-dehydrogenative coupling of N-carbamoyl tetrahydroisoquinolines and terminal alkynes.

Science.gov (United States)

Sun, Shutao; Li, Chengkun; Floreancig, Paul E; Lou, Hongxiang; Liu, Lei

2015-04-03

The first catalytic asymmetric cross-dehydrogenative coupling of cyclic carbamates and terminal alkynes has been established. The reaction features high enantiocontrol and excellent functional group tolerance and displays a wide range of structurally and electronically diverse carbamates as well as terminal alkynes. N-Acyl hemiaminals were identified as the reactive intermediates through preliminary control experiments. Employing readily removable carbamates as substrates rather than traditionally adopted N-aryl amines allows applications in complex molecule synthesis and therefore advances the C-H functionalization strategy to a synthetically useful level.

Detection of Organics at Mars: How Wet Chemistry Onboard SAM Helps

Science.gov (United States)

Buch, A.; Freissinet, Caroline; Szopa, C.; Glavin, D.; Coll, P.; Cabane, M.; Eigenbrode, J.; Navarro-Gonzalez, R.; Coscia, D.; Teinturier, S.;

Sillica Gel-Amine from Geothermal Sludge

Science.gov (United States)

Muljani, S.; Pujiastuti, C.; Wicaksono, P.; Lutfianingrum, R.

2018-01-01

Silica Gel-Amine (SGA) has been made from geothermal sludge by grafting amine method. Sodium silicate solution is prepared by extracted geothermal sludge powder using sodium hidroxide solution then acidification in the range of pH 5 - 9 by using tartaric acid 1N. The grafting process uses 1 ml of ammonia solution and 10 ml of toluene at a rate of 0.1 ml min-1 accompanied by a reflux process. The amine grafting is done in two methods. The first method is grafting amine in silicate solution and the second method is grafting amine in washed gel. Product SGA was confirmed by FTIR, TGA-DTG and BET characterization. The results show that the pH affects the amount of amine that is grafted onto silica gel. Differences in grafting method affect the size of the pore and surface area. SGA product prepared by grafting washed gel at pH 8 have pore diameter of 12.06 nm, surface area of 173.44 m2g-1, and mass of decomposed amine compound 0.4 mg. In the presence of amine groups on the silica gel surface, these adsorbents may be able to selectively adsorb CO2 gas from natural gas.

Electronic patient self-assessment and management (SAM): a novel framework for cancer survivorship.

Science.gov (United States)

Vickers, Andrew J; Salz, Talya; Basch, Ethan; Cooperberg, Matthew R; Carroll, Peter R; Tighe, Foss; Eastham, James; Rosen, Raymond C

2010-06-17

We propose a novel framework for management of cancer survivorship: electronic patient Self-Assessment and Management (SAM). SAM is a framework for transfer of information to and from patients in such a way as to increase both the patient's and the health care provider's understanding of the patient's progress, and to help ensure that patient care follows best practice. Patients who participate in the SAM system are contacted by email at regular intervals and asked to complete validated questionnaires online. Patient responses on these questionnaires are then analyzed in order to provide patients with real-time, online information about their progress and to provide them with tailored and standardized medical advice. Patient-level data from the questionnaires are ported in real time to the patient's health care provider to be uploaded to clinic notes. An initial version of SAM has been developed at Memorial Sloan-Kettering Cancer Center (MSKCC) and the University of California, San Francisco (UCSF) for aiding the clinical management of patients after surgery for prostate cancer. Pilot testing at MSKCC and UCSF suggests that implementation of SAM systems are feasible, with no major problems with compliance (> 70% response rate) or security. SAM is a conceptually simple framework for passing information to and from patients in such a way as to increase both the patient's and the health care provider's understanding of the patient's progress, and to help ensure that patient care follows best practice.

Electronic patient self-assessment and management (SAM: a novel framework for cancer survivorship

Directory of Open Access Journals (Sweden)

Tighe Foss

2010-06-01

Full Text Available Abstract Background We propose a novel framework for management of cancer survivorship: electronic patient Self-Assessment and Management (SAM. SAM is a framework for transfer of information to and from patients in such a way as to increase both the patient's and the health care provider's understanding of the patient's progress, and to help ensure that patient care follows best practice. Methods Patients who participate in the SAM system are contacted by email at regular intervals and asked to complete validated questionnaires online. Patient responses on these questionnaires are then analyzed in order to provide patients with real-time, online information about their progress and to provide them with tailored and standardized medical advice. Patient-level data from the questionnaires are ported in real time to the patient's health care provider to be uploaded to clinic notes. An initial version of SAM has been developed at Memorial Sloan-Kettering Cancer Center (MSKCC and the University of California, San Francisco (UCSF for aiding the clinical management of patients after surgery for prostate cancer. Results Pilot testing at MSKCC and UCSF suggests that implementation of SAM systems are feasible, with no major problems with compliance (> 70% response rate or security. Conclusion SAM is a conceptually simple framework for passing information to and from patients in such a way as to increase both the patient's and the health care provider's understanding of the patient's progress, and to help ensure that patient care follows best practice.

The Performance of CSAM SAM when Cycle Length is extended

Energy Technology Data Exchange (ETDEWEB)

Roh, Kyung-ho; Moon, Sang-rae [KHNP, Daejeon (Korea, Republic of)

2016-10-15

In order to verify validation of that, CPC Axial Power Distribution is compared with Axial Power Distribution based on ICI every week. The difference between CPC Axial Power Distribution and Axial Power Distribution based on ICI increases according as fuels are burned. It is called CPC Axial Power Distribution Root Mean Square Error (CPC RMS Error). SAM and calibration of ex-core detector are important factors influencing the magnitude of the difference. According to vendor, the difference is limited by 8%. Otherwise, CPC penalty increases as many as difference increase. Therefore, KHNP developed Constrained Simulated Annealing Method (CSAM), which has better performance than that of Least Square Method (LSM), to calculate SAM constant. The CSA SAM contributed largely to maintain CPC operating margin. Somewhat, KHNP is developing the technology to be able to operate nuclear power plants for 24 month to optimize their efficiency. This paper shows trends of CPC RMS Error in a case of 24 months operation. Trends are based on data of a few OPR1000s under operation. It is data of OPR1000s that CSA SAM is applied. KHNP is developing the technology to extend operation cycle length in order to optimize the operation efficiency of OPR1000. To verify effect of extended operation cycle length on CPC, CPC Axial Power Distribution RMS Error in a case of 24 months operation was expected using operation data of six cycles in OPR1000. In cases that CPC Axial Power Distribution RMS Error exceeds threshold, operation margin is decreased due to CPC penalty. To prevent CPC operation margin from being decreased, improved method to calculate SAM or to calibrate ex-core detector is required. KHNP will consider the way to maintain CPC operation margin along with 24 month operation technology development, hereafter.

Celiac Disease in Children with Severe Acute Malnutrition (SAM): A Hospital Based Study.

Science.gov (United States)

Beniwal, Neetu; Ameta, Gaurav; Chahar, Chandra Kumar

2017-05-01

To evaluate the prevalence and clinical features of Celiac disease among children with severe acute malnutrition (SAM). This prospective observational study was conducted in PBM Children Hospital, Bikaner from July 2012 through December 2013. All consecutively admitted children with SAM were recruited. All subjects were screened for Celiac disease by serological test for IgA-anti tissue Transglutaminase (IgA tTG) antibodies. All seropositive children underwent upper gastrointestinal endoscopy for small bowel biopsy for the confirmation. Clinical features of patients with and without celiac disease were compared. The sero-prevalence (IgA tTg positivity) of Celiac disease was found to be 15.38% while prevalence of biopsy confirmed Celiac disease was 14.42% among SAM children. Abdominal distension, diarrhea, anorexia, constipation, pain in abdomen, vitamin deficiencies, edema, clubbing and mouth ulcers were more common in patients of Celiac disease compared to patients without Celiac disease but the difference was statistically significant only for abdominal distension and pain abdomen. There is a high prevalence of Celiac disease in SAM. Screening for Celiac disease (especially in presence of pain abdomen and abdominal distension) should be an essential part of work-up in all children with SAM.

The economics of amine usage

International Nuclear Information System (INIS)

Fountain, M.J.

1994-01-01

Research carried out over the past decade in the USA (funded by EPRI) and by the CEGB/Nuclear Electric in the UK has identified several thermally stable, low-toxicity 'advanced' amines with good high-temperature basicity and low steam-water distribution ratio. As a direct result of this work several US PWR stations are now evaluating monoethanolamine (ETA) and Nuclear Electric's Wylfa Power Station (magnox) now doses 5 aminopentanol (5AP) instead of AMP, which had successfully combated erosion-corrosion for the past nine years. It has recently been stated that the use of 5AP ''...could save Nuclear Electric up to 1.5M pounds per year''. To provide US power station chemists with a tool for tailoring amine dosage to their own plant requirements EPRI has developed a computer model, Aminmod, which can, with user-defined circuit parameters and amine feed concentrations, calculate amine concentrations and pH(t) values at various points around the circuit. To complement this model a user-friendly spreadsheet program is being developed which will work in conjunction with Aminmod, via active links, to calculate the total operating cost associated with the selected amine dosing regime and compare alternative scenarios. This paper discusses the relationship between the technical and economic aspects of choosing an amine dosing regime and draws on combined Aminmod/spreadsheet results to illustrate how differences in amine properties can influence the optimum economic solution for a typical PWR. (author). 3 figs., 2 tabs., 5 refs

SAM-dependent enzyme-catalysed pericyclic reactions in natural product biosynthesis

Science.gov (United States)

Ohashi, Masao; Liu, Fang; Hai, Yang; Chen, Mengbin; Tang, Man-Cheng; Yang, Zhongyue; Sato, Michio; Watanabe, Kenji; Houk, K. N.; Tang, Yi

2017-09-01

Pericyclic reactions—which proceed in a concerted fashion through a cyclic transition state—are among the most powerful synthetic transformations used to make multiple regioselective and stereoselective carbon-carbon bonds. They have been widely applied to the synthesis of biologically active complex natural products containing contiguous stereogenic carbon centres. Despite the prominence of pericyclic reactions in total synthesis, only three naturally existing enzymatic examples (the intramolecular Diels-Alder reaction, and the Cope and the Claisen rearrangements) have been characterized. Here we report a versatile S-adenosyl-L-methionine (SAM)-dependent enzyme, LepI, that can catalyse stereoselective dehydration followed by three pericyclic transformations: intramolecular Diels-Alder and hetero-Diels-Alder reactions via a single ambimodal transition state, and a retro-Claisen rearrangement. Together, these transformations lead to the formation of the dihydropyran core of the fungal natural product, leporin. Combined in vitro enzymatic characterization and computational studies provide insight into how LepI regulates these bifurcating biosynthetic reaction pathways by using SAM as the cofactor. These pathways converge to the desired biosynthetic end product via the (SAM-dependent) retro-Claisen rearrangement catalysed by LepI. We expect that more pericyclic biosynthetic enzymatic transformations remain to be discovered in naturally occurring enzyme ‘toolboxes’. The new role of the versatile cofactor SAM is likely to be found in other examples of enzyme catalysis.

Multiple endmember spectral-angle-mapper (SAM) analysis improves discrimination of Savanna tree species

CSIR Research Space (South Africa)

Cho, Moses A

2009-08-01

Full Text Available of this paper was to evaluate the classification performance of a multiple-endmember spectral angle mapper (SAM) classification approach in discriminating seven common African savanna tree species and to compare the results with the traditional SAM classifier...

Amines, Astrocytes and Arousal

OpenAIRE

Bazargani, N.; Attwell, D.

2017-01-01

Amine neurotransmitters, such as noradrenaline, mediate arousal, attention, and reward in the CNS. New data suggest that, from flies to mammals, a major mechanism for amine transmitter action is to raise astrocyte [Ca2+]i and release gliotransmitters that modulate neuronal activity and behavior.

Extraction of sulphates by long chain amines; Extraction des sulfates par les amines a longues chaines

Energy Technology Data Exchange (ETDEWEB)

Boirie, Ch [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1959-05-15

The extraction of sulphuric acid by long chain amines in organic solution has been studied with a view to determining the value of the stability constants of the amine sulphates and bi-sulphates formed. We have concentrated chiefly on uranium sulphate and thorium sulphate. The formulae of the complexes extractable with amines have been established, as well as the corresponding dissociation constants. We have observed that for uranium sulphate the formula of the complex depends only on the nature of the amine, whereas for thorium this formula varies with the amine structure. From the formulae determined and the value of the constants calculated, we have been able to establish the best conditions for uranium and thorium extraction and also for a separation of these two elements. Finally we propose an application of this study to the determination of uranium in ores, where the separation of uranium by this method is particularly easy and complete. (author) [French] L'extraction de l'acide sulfurique par des amines a longues chaines en solution organique a ete etudiee en vue de la determination de la valeur des constantes de stabilite des sulfates et bisulfates d'amines formes. Parmi les sulfates, nous nous sommes particulierement interesses au sulfate d'uranium et au sulfate de thorium. Nous avons determine les formules des complexes extractibles avec les amines, ainsi que les constantes de dissociation correspondantes. Nous avons remarque que pour le sulfate d'uranium, la formule du complexe ne depend que de la nature de l'amine, alors que pour le thorium cette formule varie avec la structure de l'amine. Les formules determinees et la valeur des constantes calculees, nous ont permis de decrire les meilleures conditions d'extraction de l'uranium et du thorium ainsi que celles d'une separation de ces deux elements. Nous proposons enfin une application de cette etude au dosage de l'uranium dans les minerais, ou la separation de l'uranium par cette methode est

GoSam. A program for automated one-loop calculations

Energy Technology Data Exchange (ETDEWEB)

Cullen, G. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Greiner, N.; Heinrich, G.; Reiter, T. [Max-Planck-Institut fuer Physik, Muenchen (Germany); Luisoni, G. [Durham Univ. (United Kingdom). Inst. for Particle Physics Phenomenology; Mastrolia, P. [Max-Planck-Institut fuer Physik, Muenchen (Germany); Padua Univ. (Italy). Dipt. di Fisica; Ossola, G. [City Univ. of New York, NY (United States). New York City College of Technology; Tramontano, F. [European Organization for Nuclear Research (CERN), Geneva (Switzerland)

2011-11-15

The program package GoSam is presented which aims at the automated calculation of one-loop amplitudes for multi-particle processes. The amplitudes are generated in terms of Feynman diagrams and can be reduced using either D-dimensional integrand-level decomposition or tensor reduction, or a combination of both. GoSam can be used to calculate one-loop corrections to both QCD and electroweak theory, and model files for theories Beyond the Standard Model can be linked as well. A standard interface to programs calculating real radiation is also included. The flexibility of the program is demonstrated by various examples. (orig.)

GoSam. A program for automated one-loop calculations

International Nuclear Information System (INIS)

Cullen, G.; Greiner, N.; Heinrich, G.; Reiter, T.; Luisoni, G.

2011-11-01

The program package GoSam is presented which aims at the automated calculation of one-loop amplitudes for multi-particle processes. The amplitudes are generated in terms of Feynman diagrams and can be reduced using either D-dimensional integrand-level decomposition or tensor reduction, or a combination of both. GoSam can be used to calculate one-loop corrections to both QCD and electroweak theory, and model files for theories Beyond the Standard Model can be linked as well. A standard interface to programs calculating real radiation is also included. The flexibility of the program is demonstrated by various examples. (orig.)

GoSam: A program for automated one-loop calculations

International Nuclear Information System (INIS)

Cullen, G; Greiner, N; Heinrich, G; Mastrolia, P; Reiter, T; Luisoni, G; Ossola, G; Tramontano, F

2012-01-01

The program package GoSam is presented which aims at the automated calculation of one-loop amplitudes for multi-particle processes. The amplitudes are generated in terms of Feynman diagrams and can be reduced using either D-dimensional integrand-level decomposition or tensor reduction, or a combination of both. GoSam can be used to calculate one-loop corrections to both QCD and electroweak theory, and model files for theories Beyond the Standard Model can be linked as well. A standard interface to programs calculating real radiation is also included. The flexibility of the program is demonstrated by various examples.

Photocatalytic organic transformation by layered double hydroxides: highly efficient and selective oxidation of primary aromatic amines to their imines under ambient aerobic conditions.

Science.gov (United States)

Yang, Xiu-Jie; Chen, Bin; Li, Xu-Bing; Zheng, Li-Qiang; Wu, Li-Zhu; Tung, Chen-Ho

2014-06-25

We report the first application of layered double hydroxide as a photocatalyst in the transformation of primary aromatic amines to their corresponding imines with high efficiency and selectivity by using oxygen in an air atmosphere as a terminal oxidant under light irradiation.

General Quality Control (QC) Guidelines for SAM Methods

Science.gov (United States)

Learn more about quality control guidelines and recommendations for the analysis of samples using the methods listed in EPA's Selected Analytical Methods for Environmental Remediation and Recovery (SAM).

Metal-Free Oxidation of Primary Amines to Nitriles through Coupled Catalytic Cycles.

Science.gov (United States)

Lambert, Kyle M; Bobbitt, James M; Eldirany, Sherif A; Kissane, Liam E; Sheridan, Rose K; Stempel, Zachary D; Sternberg, Francis H; Bailey, William F

2016-04-04

Synergism among several intertwined catalytic cycles allows for selective, room temperature oxidation of primary amines to the corresponding nitriles in 85-98% isolated yield. This metal-free, scalable, operationally simple method employs a catalytic quantity of 4-acetamido-TEMPO (ACT; TEMPO=2,2,6,6-tetramethylpiperidine N-oxide) radical and the inexpensive, environmentally benign triple salt oxone as the terminal oxidant under mild conditions. Simple filtration of the reaction mixture through silica gel affords pure nitrile products. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The Porter-Whitesides Discrepancy: Revisiting Odd-Even Effects in Wetting Properties of n-Alkanethiolate SAMs

Directory of Open Access Journals (Sweden)

Zhengjia Wang

2015-12-01

Full Text Available This review discusses the Porter-Whitesides discrepancy in wetting properties of n-alkanethiolate self-assembled monolayers (SAMs. About 25 years ago, Whitesides and coworker failed to observe any odd-even effect in wetting, however, Porter and his coworker did, albeit in select cases. Most previous studies agreed with Whitesides’ results, suggesting the absence of the odd-even effect in hydrophobicity of n-alkanethiolate SAMs. Recent reports have, however, found the odd-even effect in hydrophobicity of n-alkanethiolate SAMs on smooth substrates, indicating that hydrophobicity, and analogous interfacial properties, of n-alkanethiolate SAMs significantly depends on the properties of substrate. Unfortunately, the Whitesides and Porter papers do not report on the quality of the surfaces used. Based on recent work, we inferred that the original discrepancy between Whitesides and Porter can be attributed to the quality of the surface. Odd-even effect of SAMs in charge transport, capacitance, friction, and SAM structure are also discussed in this review to inform the general discussion. The discrepancy between Porter's group and Whitesides’ group could be due to surface roughness, morphology, oxidation, and adventitious contaminants.

Dielectric properties of supramolecular ionic structures obtained from multifunctional carboxylic acids and amines

DEFF Research Database (Denmark)

Gonzalez, Lidia; Yu, Liyun; Hvilsted, Søren

2014-01-01

The dielectric properties of several supramolecular ionic polymers and networks, linked by the ammonium salts of hexamethylene diamine (HMDA), tris(2-aminoethyl)amine (TAEA), poly(propylene imine) (PPI) dendrimers and two short bis carboxymethyl ether-terminated poly(ethylene glycol)s (Di......COOH-PEG), are reported in this paper. All supramolecular ionic polymers and networks exhibit very high relative dielectric permittivities ( 3 0 )( 10 2 – 10 6 ) at low frequencies, and signi fi cantly lower values (from 1 up to 26) at high frequencies. Additionally, the dielectric properties of supramolecular ionic......), are investigated. Here the relative dielectric permittivities of the supramolecular ionic structures formed with the multifunctional carboxylic acids were lower than those from the supramolecular ionic structures formed with the two carboxymethyl ether-terminated poly(ethylene glycol)s....

Safety and Waste Management for SAM Pathogen Methods

Science.gov (United States)

The General Safety and Waste Management page offers section-specific safety and waste management details for the pathogens included in EPA's Selected Analytical Methods for Environmental Remediation and Recovery (SAM).

Safety and Waste Management for SAM Biotoxin Methods

Science.gov (United States)

The General Safety and Waste Management page offers section-specific safety and waste management details for the biotoxins included in EPA's Selected Analytical Methods for Environmental Remediation and Recovery (SAM).

ISO19770-1:2012 SAM process guidance

CERN Document Server

Canavan, Rory

2012-01-01

The pocket guide offers a concise summary of the principles of software asset management as conveyed by ISO 19770-1: 2012, and provides advice and guidance on how to kick-start your own SAM programme - something the Standard alone doesn't offer.

Safety and Waste Management for SAM Chemistry Methods

Science.gov (United States)

The General Safety and Waste Management page offers section-specific safety and waste management details for the chemical analytes included in EPA's Selected Analytical Methods for Environmental Remediation and Recovery (SAM).

Safety and Waste Management for SAM Radiochemical Methods

Science.gov (United States)

The General Safety and Waste Management page offers section-specific safety and waste management details for the radiochemical analytes included in EPA's Selected Analytical Methods for Environmental Remediation and Recovery (SAM).

Targeting EphA2-Sam and Its Interactome: Design and Evaluation of Helical Peptides Enriched in Charged Residues.

Science.gov (United States)

Mercurio, Flavia A; Marasco, Daniela; Di Natale, Concetta; Pirone, Luciano; Costantini, Susan; Pedone, Emilia M; Leone, Marilisa

2016-11-17

The EphA2 receptor controls diverse physiological and pathological conditions and its levels are often upregulated in cancer. Targeting receptor overexpression, through modulation of endocytosis and consequent degradation, appears to be an appealing strategy for attacking tumor malignancy. In this scenario, the Sam domain of EphA2 plays a pivotal role because it is the site where protein regulators of endocytosis and stability are recruited by means of heterotypic Sam-Sam interactions. Because EphA2-Sam heterotypic complexes are largely based on electrostatic contacts, we have investigated the possibility of attacking these interactions with helical peptides enriched in charged residues. Several peptide sequences with high predicted helical propensities were designed, and detailed conformational analyses were conducted by diverse techniques including NMR, CD, and molecular dynamics (MD) simulations. Interaction studies were also performed by NMR, surface plasmon resonance (SPR), and microscale thermophoresis (MST) and led to the identification of two peptides capable of binding to the first Sam domain of Odin. These molecules represent early candidates for the generation of efficient Sam domain binders and antagonists of Sam-Sam interactions involving EphA2. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

SAM-CE, Time-Dependent 3-D Neutron Transport, Gamma Transport in Complex Geometry by Monte-Carlo

International Nuclear Information System (INIS)

2003-01-01

1 - Nature of physical problem solved: The SAM-CE system comprises two Monte Carlo codes, SAM-F and SAM-A. SAM-F supersedes the forward Monte Carlo code, SAM-C. SAM-A is an adjoint Monte Carlo code designed to calculate the response due to fields of primary and secondary gamma radiation. The SAM-CE system is a FORTRAN Monte Carlo computer code designed to solve the time-dependent neutron and gamma-ray transport equations in complex three-dimensional geometries. SAM-CE is applicable for forward neutron calculations and for forward as well as adjoint primary gamma-ray calculations. In addition, SAM-CE is applicable for the gamma-ray stage of the coupled neutron-secondary gamma ray problem, which may be solved in either the forward or the adjoint mode. Time-dependent fluxes, and flux functionals such as dose, heating, count rates, etc., are calculated as functions of energy, time and position. Multiple scoring regions are permitted and these may be either finite volume regions or point detectors or both. Other scores of interest, e.g., collision and absorption densities, etc., are also made. 2 - Method of solution: A special feature of SAM-CE is its use of the 'combinatorial geometry' technique which affords the user geometric capabilities exceeding those available with other commonly used geometric packages. All nuclear interaction cross section data (derived from the ENDF for neutrons and from the UNC-format library for gamma-rays) are tabulated in point energy meshes. The energy meshes for neutrons are internally derived, based on built-in convergence criteria and user- supplied tolerances. Tabulated neutron data for each distinct nuclide are in unique and appropriate energy meshes. Both resolved and unresolved resonance parameters from ENDF data files are treated automatically, and extremely precise and detailed descriptions of cross section behaviour is permitted. Such treatment avoids the ambiguities usually associated with multi-group codes, which use flux

Oxidation of amines by flavoproteins.

Science.gov (United States)

Fitzpatrick, Paul F

2010-01-01

Many flavoproteins catalyze the oxidation of primary and secondary amines, with the transfer of a hydride equivalent from a carbon-nitrogen bond to the flavin cofactor. Most of these amine oxidases can be classified into two structural families, the D-amino acid oxidase/sarcosine oxidase family and the monoamine oxidase family. This review discusses the present understanding of the mechanisms of amine and amino acid oxidation by flavoproteins, focusing on these two structural families. Copyright 2009 Elsevier Inc. All rights reserved.

Monovalent Cation Activation of the Radical SAM Enzyme Pyruvate Formate-Lyase Activating Enzyme.

Science.gov (United States)

Shisler, Krista A; Hutcheson, Rachel U; Horitani, Masaki; Duschene, Kaitlin S; Crain, Adam V; Byer, Amanda S; Shepard, Eric M; Rasmussen, Ashley; Yang, Jian; Broderick, William E; Vey, Jessica L; Drennan, Catherine L; Hoffman, Brian M; Broderick, Joan B

2017-08-30

Pyruvate formate-lyase activating enzyme (PFL-AE) is a radical S-adenosyl-l-methionine (SAM) enzyme that installs a catalytically essential glycyl radical on pyruvate formate-lyase. We show that PFL-AE binds a catalytically essential monovalent cation at its active site, yet another parallel with B 12 enzymes, and we characterize this cation site by a combination of structural, biochemical, and spectroscopic approaches. Refinement of the PFL-AE crystal structure reveals Na + as the most likely ion present in the solved structures, and pulsed electron nuclear double resonance (ENDOR) demonstrates that the same cation site is occupied by 23 Na in the solution state of the as-isolated enzyme. A SAM carboxylate-oxygen is an M + ligand, and EPR and circular dichroism spectroscopies reveal that both the site occupancy and the identity of the cation perturb the electronic properties of the SAM-chelated iron-sulfur cluster. ENDOR studies of the PFL-AE/[ 13 C-methyl]-SAM complex show that the target sulfonium positioning varies with the cation, while the observation of an isotropic hyperfine coupling to the cation by ENDOR measurements establishes its intimate, SAM-mediated interaction with the cluster. This monovalent cation site controls enzyme activity: (i) PFL-AE in the absence of any simple monovalent cations has little-no activity; and (ii) among monocations, going down Group 1 of the periodic table from Li + to Cs + , PFL-AE activity sharply maximizes at K + , with NH 4 + closely matching the efficacy of K + . PFL-AE is thus a type I M + -activated enzyme whose M + controls reactivity by interactions with the cosubstrate, SAM, which is bound to the catalytic iron-sulfur cluster.

Controlling Nitrosamines, Nitramines, and Amines in Amine-Based CO₂ Capture Systems with Continuous Ultraviolet and Ozone Treatment of Washwater.

Science.gov (United States)

Dai, Ning; Mitch, William A

2015-07-21

Formation of nitrosamines and nitramines from reactions between flue gas NOx and the amines used in CO2 capture units has arisen as a significant concern. Washwater scrubbers can capture nitrosamines and nitramines. They can also capture amines, preventing formation of nitrosamines and nitramines downwind by amine reactions with ambient NOx. The continuous application of UV alone, or a combination of UV and ozone to the return line of a washwater treatment unit was evaluated to control the accumulation of nitrosamines, nitramines and amines in a laboratory-scale washwater unit. With model secondary amine solvents ranging from nonvolatile diethanolamine to volatile morpholine, application of 272-537 mJ/cm(2) UV incident fluence alone reduced the accumulation of nitrosamines and nitramines by approximately an order of magnitude. Modeling indicated that the gains achieved by UV treatment should increase over time, because UV treatment converts the time dependence of nitrosamine accumulation from a quadratic to a linear function. Ozone (21 mg/L) maintained low steady-state concentrations of amines in the washwater. While modeling indicated that more than 80% of nitrosamine accumulation in the washwater was associated with reaction of washwater amines with residual NOx, a reduction in nitrosamine accumulation rates due to ozone oxidation of amines was not fully realized because the ozonation products of amines reduced nitrosamine photolysis rates by competing for photons.

Oxidation of primary amines to oximes with molecular oxygen using 1,1-diphenyl-2-picrylhydrazyl and WO3/Al2O3 as catalysts.

Science.gov (United States)

Suzuki, Ken; Watanabe, Tomonari; Murahashi, Shun-Ichi

2013-03-15

The oxidative transformation of primary amines to their corresponding oximes proceeds with high efficiency under molecular oxygen diluted with molecular nitrogen (O2/N2 = 7/93 v/v, 5 MPa) in the presence of the catalysts 1,1-diphenyl-2-picrylhydrazyl (DPPH) and tungusten oxide/alumina (WO3/Al2O3). The method is environmentally benign, because the reaction requires only molecular oxygen as the terminal oxidant and gives water as a side product. Various alicyclic amines and aliphatic amines can be converted to their corresponding oximes in excellent yields. It is noteworthy that the oxidative transformation of primary amines proceeds chemoselectively in the presence of other functional groups. The key step of the present oxidation is a fast electron transfer from the primary amine to DPPH followed by proton transfer to give the α-aminoalkyl radical intermediate, which undergoes reaction with molecular oxygen and hydrogen abstraction to give α-aminoalkyl hydroperoxide. Subsequent reaction of the peroxide with WO3/Al2O3 gives oximes. The aerobic oxidation of secondary amines gives the corresponding nitrones. Aerobic oxidative transformation of cyclohexylamines to cyclohexanone oximes is important as a method for industrial production of ε-caprolactam, a raw material for Nylon 6.

The ALICE Glance Shift Accounting Management System (SAMS)

Science.gov (United States)

Martins Silva, H.; Abreu Da Silva, I.; Ronchetti, F.; Telesca, A.; Maidantchik, C.

2015-12-01

ALICE (A Large Ion Collider Experiment) is an experiment at the CERN LHC (Large Hadron Collider) studying the physics of strongly interacting matter and the quark-gluon plasma. The experiment operation requires a 24 hours a day and 7 days a week shift crew at the experimental site, composed by the ALICE collaboration members. Shift duties are calculated for each institute according to their correlated members. In order to ensure the full coverage of the experiment operation as well as its good quality, the ALICE Shift Accounting Management System (SAMS) is used to manage the shift bookings as well as the needed training. ALICE SAMS is the result of a joint effort between the Federal University of Rio de Janeiro (UFRJ) and the ALICE Collaboration. The Glance technology, developed by the UFRJ and the ATLAS experiment, sits at the basis of the system as an intermediate layer isolating the particularities of the databases. In this paper, we describe the ALICE SAMS development process and functionalities. The database has been modelled according to the collaboration needs and is fully integrated with the ALICE Collaboration repository to access members information and respectively roles and activities. Run, period and training coordinators can manage their subsystem operation and ensure an efficient personnel management. Members of the ALICE collaboration can book shifts and on-call according to pre-defined rights. ALICE SAMS features a user profile containing all the statistics and user contact information as well as the Institutes profile. Both the user and institute profiles are public (within the scope of the collaboration) and show the credit balance in real time. A shift calendar allows the Run Coordinator to plan data taking periods in terms of which subsystems shifts are enabled or disabled and on-call responsible people and slots. An overview display presents the shift crew present in the control room and allows the Run Coordination team to confirm the presence

Metal and base free synthesis of primary amines via ipso amination of organoboronic acids mediated by [bis(trifluoroacetoxy)iodo]benzene (PIFA).

Science.gov (United States)

Chatterjee, Nachiketa; Goswami, Avijit

2015-08-07

A metal and base free synthesis of primary amines has been developed at ambient temperature through ipso amination of diversely functionalized organoboronic acids, employing a combination of [bis(trifluoroacetoxy)iodo]benzene (PIFA)-N-bromosuccinimide (NBS) and methoxyamine hydrochloride as the aminating reagent. The amines were primarily obtained as their trifluoroacetate salts which on subsequent aqueous alkaline work up provided the corresponding free amines. The combination of PIFA-NBS is found to be the mildest choice compared to the commonly used strong bases (e.g. n-BuLi, Cs2CO3) for activating the aminating agent. The reaction is expected to proceed via activation of the aminating reagent followed by B-N 1,2-aryl migration.

Extraction of some acids using aliphatic amines; Extraction de quelques acides par des amines aliphatiques

Energy Technology Data Exchange (ETDEWEB)

Matutano, L [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-06-01

Hydrochloric, nitric, sulphuric, perchloric, phosphoric, acetic and formic acids in aqueous solution (0.05 to 10 M) are extracted by amberlite LA2 and trilaurylamine in solution, 5 per cent by volume, in kerosene and xylene respectively. The extraction process consists of: neutralization of the amine salt; a 'molecular extraction', i.e. an extraction using an excess of acid with respect to the stoichiometry of the amine salt. According to the behaviour of the acid during the extraction, three groups may be distinguished: completely dissociated acids, carboxylic acids, phosphoric acid. This classification is also valid for the extraction of the water which occurs simultaneously with that of the acid. An extraction mechanism is put forward for formic acid and the formation constant of its amine salt is calculated. (author) [French] Les acides chlorhydrique, nitrique, sulfurique, perchlorique, phosphorique, acetique et formique, en solution aqueuse - 0,05 a 10 M - sont extraits par l'amberlite LA2 et la trilaurylamine en solution, a 5 pour cent en volume, dans le kerosene et le xylene respectivement. L'extraction comprend: une neutralisation de l'amine par l'acide avec formation d'un sel d'amine; une 'extraction moleculaire', c'est-a-dire une extraction d'acide en exces par rapport a la stoechiometrie du sel d'amine. Suivant le comportement des acides au cours de l'extraction nous distinguons trois groupes: acides entierement dissocies, acides carboxyliques, acide phosphorique. Cette classification est egalement valable pour l'extraction de l'eau qui est simultanee a celle de l'acide. Un mecanisme d'extraction pour l'acide formique est propose et nous calculons la constante de formation de son sel d'amine. (auteur)

Molten Salt Power Tower Cost Model for the System Advisor Model (SAM)

Energy Technology Data Exchange (ETDEWEB)

Turchi, C. S.; Heath, G. A.

2013-02-01

This report describes a component-based cost model developed for molten-salt power tower solar power plants. The cost model was developed by the National Renewable Energy Laboratory (NREL), using data from several prior studies, including a contracted analysis from WorleyParsons Group, which is included herein as an Appendix. The WorleyParsons' analysis also estimated material composition and mass for the plant to facilitate a life cycle analysis of the molten salt power tower technology. Details of the life cycle assessment have been published elsewhere. The cost model provides a reference plant that interfaces with NREL's System Advisor Model or SAM. The reference plant assumes a nominal 100-MWe (net) power tower running with a nitrate salt heat transfer fluid (HTF). Thermal energy storage is provided by direct storage of the HTF in a two-tank system. The design assumes dry-cooling. The model includes a spreadsheet that interfaces with SAM via the Excel Exchange option in SAM. The spreadsheet allows users to estimate the costs of different-size plants and to take into account changes in commodity prices. This report and the accompanying Excel spreadsheet can be downloaded at https://sam.nrel.gov/cost.

Alkyne- and 1,6-elimination- succinimidyl carbonate - terminated heterobifunctional poly(ethylene glycol) for reversible "Click" PEGylation.

Science.gov (United States)

Xie, Yumei; Duan, Shaofeng; Forrest, M Laird

2010-01-01

A new heterobifunctional (succinimidyl carbonate, SC)-activated poly(ethylene glycol) (PEG) with a reversible 1,6-elimination linker and a terminal alkyne for "click" chemistry was synthesized with high efficiency and low polydispersity. The α-alkyne-ω-hydroxyl PEG was first prepared using trimethylsilyl-2-propargyl alcohol as an initiator for ring-opening polymerization of ethylene oxide followed by mild deprotection with tetrabutylammonium fluoride. The hydroxy end was then modified with diglycolic anhydride to generate α-alkyne-ω-carboxylic acid PEG. The reversible 1, 6-elimination linker was introduced by conjugation of a hydroxymethyl phenol followed by activation with N,N'-disuccinimidyl carbonate to generate the heterobifunctional α-alkyne-ω-SC PEG. The terminal alkyne is available for "click" conjugation to azido ligands via 1,3-dipolar cycloaddition, and the succinimidyl carbonate will form a reversible conjugate to amines (e.g. in proteins) that can release the unaltered amine after base or enzyme catalyzed cleavage of the 1,6-linker.

Fabrication and tribological properties of self-assembled monolayer of n-alkyltrimethoxysilane on silicon: Effect of SAM alkyl chain length

International Nuclear Information System (INIS)

Huo, Lixia; Du, Pengcheng; Zhou, Hui; Zhang, Kaifeng; Liu, Peng

2017-01-01

Highlights: • n-Alkyltrimethoxysilanes with various chain lengths were self-assembled on silicon. • Effect of alkyl chain lengths (C6, C12, or C18) on the SAMs was investigated. • Surface roughness of the SAMs decreased with increasing the alkyl chain lengths. • The C 12 -SAM possessed superior friction reduction and wear resistance. - Abstract: It is well known that the self-assembled organic molecules on a solid surface exhibit the friction-reducing performance. However, the effect of the molecular size of the self-assembled organic molecules has not been established. In the present work, self-assembled monolayers (SAMs) of n-alkyltrimethoxysilanes with different alkyl chain lengths (C 6 , C 12 , or C 18 ) were fabricated on silicon substrate. The water contact angles of the SAMs increased from 26.8° of the hydroxylated silicon substrate to near 60° after self-assembly. The atomic force microscopy (AFM) analysis results showed that the mean roughness (R a ) of the SAMs decreased with increasing the alkyl chain length. The tribological properties of the SAMs sliding against Al 2 O 3 ball were evaluated on an UMT-2 tribometer, and the worn surfaces of the samples were analyzed by means of Nano Scratch Tester and surface profilometry. It was found that lowest friction coefficient and smallest width of wear were achieved with the SAMs of C 12 alkyl chain (C 12 -SAM). The superior friction reduction and wear resistance of the SAMs in comparison with the bare silicon substrate are attributed to good adhesion of the self-assembled films to the substrate, especially the C 12 -SAM with desirable alkyl chain length.

Ionic networks derived from the protonation of dendritic amines with carboxylic acid end‐functionalized PEGs

DEFF Research Database (Denmark)

Gonzalez, Lidia; Skov, Anne Ladegaard; Hvilsted, Søren

2013-01-01

The synthesis and characterization of novel ionic networks linked by the ammonium salts of poly(propylene imine) (PPI) dendrimers of the first (PPI G1) and second (PPI G2) generation and two short bis carboxymethyl ether terminated poly(ethylene glycol)s (DiCOOH‐PEG) with different molecular...... weights (Mn ∼ 250 and Mn ∼ 600) are reported. Likewise, an ionic network based on PPI G1 and a long αω‐dicarboxylic acid functionalized PEG (Mn ∼ 4800) were evaluated. Simpler ionic structures based on tris(2‐aminoethyl)amine or hexamethylene diamine and the short DiCOOH‐PEGs are also investigated....... The ionic structures formed were confirmed by differential scanning calorimetry, Fourier Transform Infrared spectroscopy in the attenuated‐total‐reflection mode, and 1H‐13C NMR spectroscopy. A comprehensive 1H NMR analysis revealed that only the primary amines of the PPI G1 dendrimer residing...

Fabrication and Surface Properties of Composite Films of SAM/Pt/ZnO/SiO 2

KAUST Repository

Yao, Ke Xin

2008-12-16

Through synthetic architecture and functionalization with self-assembled monolayers (SAMs), complex nanocomposite films of SAM/Pt/ZnO/SiO2 have been facilely prepared in this work. The nanostructured films are highly uniform and porous, showing a wide range of tunable wettabilities from superhydrophilicity to superhydrophobicity (water contact angles: 0° to 170°). Our approach offers synthetic flexibility in controlling film architecture, surface topography, coating texture, crystallite size, and chemical composition of modifiers (e.g., SAMs derived from alkanethiols). For example, wettability properties of the nanocomposite films can be finely tuned with both inorganic phase (i.e., ZnO/SiO2 and Pt/ZnO/SiO2) and organic phase (i.e., SAMs on Pt/ZnO/SiO2). Due to the presence of catalytic components Pt/ZnO within the nanocomposites, surface reactions of the organic modifiers can further take place at room temperature and elevated temperatures, which provides a means for SAM formation and elimination. Because the Pt/ZnO forms an excellent pair of metal-semiconductors for photocatalysis, the anchored SAMs can also be modified or depleted by UV irradiation (i.e., the films possess self-cleaning ability). Potential applications of these nanocomposite films have been addressed. Our durability tests also confirm that the films are thermally stable and structurally robust in modification- regeneration cycles. © 2008 American Chemical Society.

Annals of SAM meeting `96. National meeting on precious metals; Anales de las jornadas SAM `96. Encuentro nacional de metales preciosos

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-12-31

Works are presented at the SAM meeting `96 of the Argentine Materials Association. The papers can be grouped under the following main topics: physical metallurgy; ceramics; polymers; precious metals; extractive metallurgy; corrosion; powder metallurgy. refs., ills.

Fabrication and tribological properties of self-assembled monolayer of n-alkyltrimethoxysilane on silicon: Effect of SAM alkyl chain length

Energy Technology Data Exchange (ETDEWEB)

Huo, Lixia [National Key Laboratory of Science and Technology on Vacuum Technology and Physics, Lanzhou Institute of Physics, Lanzhou, Gansu 730010 (China); Institute of Polymer Science and Engineering, College of Chemistry and Chemical Engineering, Lanzhou University, Gansu 730000 (China); Du, Pengcheng [Institute of Polymer Science and Engineering, College of Chemistry and Chemical Engineering, Lanzhou University, Gansu 730000 (China); Zhou, Hui; Zhang, Kaifeng [National Key Laboratory of Science and Technology on Vacuum Technology and Physics, Lanzhou Institute of Physics, Lanzhou, Gansu 730010 (China); Liu, Peng, E-mail: pliu@lzu.edu.cn [Institute of Polymer Science and Engineering, College of Chemistry and Chemical Engineering, Lanzhou University, Gansu 730000 (China)

2017-02-28

Highlights: • n-Alkyltrimethoxysilanes with various chain lengths were self-assembled on silicon. • Effect of alkyl chain lengths (C6, C12, or C18) on the SAMs was investigated. • Surface roughness of the SAMs decreased with increasing the alkyl chain lengths. • The C{sub 12}-SAM possessed superior friction reduction and wear resistance. - Abstract: It is well known that the self-assembled organic molecules on a solid surface exhibit the friction-reducing performance. However, the effect of the molecular size of the self-assembled organic molecules has not been established. In the present work, self-assembled monolayers (SAMs) of n-alkyltrimethoxysilanes with different alkyl chain lengths (C{sub 6}, C{sub 12}, or C{sub 18}) were fabricated on silicon substrate. The water contact angles of the SAMs increased from 26.8° of the hydroxylated silicon substrate to near 60° after self-assembly. The atomic force microscopy (AFM) analysis results showed that the mean roughness (R{sub a}) of the SAMs decreased with increasing the alkyl chain length. The tribological properties of the SAMs sliding against Al{sub 2}O{sub 3} ball were evaluated on an UMT-2 tribometer, and the worn surfaces of the samples were analyzed by means of Nano Scratch Tester and surface profilometry. It was found that lowest friction coefficient and smallest width of wear were achieved with the SAMs of C{sub 12} alkyl chain (C{sub 12}-SAM). The superior friction reduction and wear resistance of the SAMs in comparison with the bare silicon substrate are attributed to good adhesion of the self-assembled films to the substrate, especially the C{sub 12}-SAM with desirable alkyl chain length.

Chemoselective organocatalytic aerobic oxidation of primary amines to secondary imines.

Science.gov (United States)

Wendlandt, Alison E; Stahl, Shannon S

2012-06-01

Biomimetic aerobic oxidation of primary benzylic amines has been achieved by using a quinone catalyst. Excellent selectivity is observed for primary, unbranched benzylic amines relative to secondary/tertiary amines, branched benzylic amines, and aliphatic amines. The exquisite selectivity for benzylic amines enables oxidative self-sorting within dynamic mixtures of amines and imines to afford high yields of cross-coupled imine products.

The Combustion Experiment on the Sample Analysis at Mars (SAM) Instrument Suite on the Curiosity Rover

Science.gov (United States)

Stern, J. C.; Malespin, C. A.; Eigenbrode, J. L.; Graham, H. V.; Archer, P. D., Jr.; Brunner, A. E.; Freissinet, C.; Franz, H. B.; Fuentes, J.; Glavin, D. P.;

Enantioselective Direct α-Amination of Aldehydes via a Photoredox Mechanism: A Strategy for Asymmetric Amine Fragment Coupling

OpenAIRE

Cecere, Giuseppe; Koenig, Christian M.; Alleva, Jennifer L.; MacMillan, David W. C.

2013-01-01

The direct, asymmetric α-amination of aldehydes has been accomplished via a combination of photoredox and organocatalysis. Photon-generated, nitrogen-centered radicals undergo enantioselective α-addition to catalytically formed chiral enamines to directly produce stable α-amino aldehyde adducts bearing synthetically useful amine substitution patterns. Incorporation of a photolabile group on the amine precursor obviates the need to employ a photoredox catalyst in this transformation. Important...

Kuula. Kuu artist Sam Sparro. Kuu plaat / Mart Juur

Index Scriptorium Estoniae

Juur, Mart, 1964-

2008-01-01

Artistist Sam Sparrost. Heliplaatidest: "Sex And The City" Original Motion Picture Soundtrack, "Maestro: Blue Note Trip", Melvin/Soo/Remmel/Julm "Geografix", Alanis Morrisette "Flavors Of Entanglement", Guillemots "Red"

Amine synergism in uranium extraction

International Nuclear Information System (INIS)

Rinelli, G.; Abbruzzese, C.

1977-01-01

Commercial products based on C 8 to C 12 tertiary amine mixtures are now widely used in the solvent extraction of uranium from sulphuric pregnant solutions. The satisfactory results generally obtained have never required an analysis of the synergistic effects of amine combinations similar to that carried out for the organo-phosphorus compounds. In the research described the increase in the extraction power of an organic phase composed of an amine binary mixture was studied with regard to an aqueous solution from the sulphuric acid treatment of uranium ore. On the basis of the experimental results obtained, it is possible to select the best composition of the amine mixture to ensure a percentage increase in uranium recovery. Bearing in mind the tendency for the yellow-cake price to rise, the study is considered to be a useful contribution in the context of commercial products currently available on the market. (author)

Adsorption of hyaluronic acid on solid supports: role of pH and surface chemistry in thin film self-assembly.

Science.gov (United States)

Choi, Jae-Hyeok; Kim, Seong-Oh; Linardy, Eric; Dreaden, Erik C; Zhdanov, Vladimir P; Hammond, Paula T; Cho, Nam-Joon

2015-06-15

Owing to its biocompatibility, resistance to biofouling, and desirable physicochemical and biological properties, hyaluronic acid (HA) has been widely used to modify the surface of various materials. The role of various physicochemical factors in HA adsorption remains, however, to be clarified. Herein, we employed quartz crystal microbalance with dissipation (QCM-D) in order to investigate HA adsorption at different pH conditions onto three substrates-silicon oxide, amine-terminated self-assembled monolayer (SAM) on gold, and carboxylic acid-terminated SAM on gold. The QCM-D experiments indicated specific pH conditions where either strong or weak HA adsorption occurs. The morphology of the adsorbed HA layers was investigated by atomic force microscopy (AFM), and we identified that strong HA adsorption produced a complete, homogenous and smooth HA layer, while weak HA adsorption resulted in rough and inhomogeneous HA layers. The observed specifics of the kinetics of HA adsorption, including a short initial linear phase and subsequent long non-linear phase, were described by using a mean-field kinetic model taking HA diffusion limitations and reconfiguration in the adsorbed state into account. The findings extend the physicochemical background of design strategies for improving the use of passive HA adsorption for surface modification applications. Copyright © 2015 Elsevier Inc. All rights reserved.

Fabrication and Surface Properties of Composite Films of SAM/Pt/ZnO/SiO 2

KAUST Repository

Yao, Ke Xin; Zeng, Hua Chun

2008-01-01

Through synthetic architecture and functionalization with self-assembled monolayers (SAMs), complex nanocomposite films of SAM/Pt/ZnO/SiO2 have been facilely prepared in this work. The nanostructured films are highly uniform and porous, showing a

Fabrication and tribological properties of self-assembled monolayer of n-alkyltrimethoxysilane on silicon: Effect of SAM alkyl chain length

Science.gov (United States)

Huo, Lixia; Du, Pengcheng; Zhou, Hui; Zhang, Kaifeng; Liu, Peng

2017-02-01

It is well known that the self-assembled organic molecules on a solid surface exhibit the friction-reducing performance. However, the effect of the molecular size of the self-assembled organic molecules has not been established. In the present work, self-assembled monolayers (SAMs) of n-alkyltrimethoxysilanes with different alkyl chain lengths (C6, C12, or C18) were fabricated on silicon substrate. The water contact angles of the SAMs increased from 26.8° of the hydroxylated silicon substrate to near 60° after self-assembly. The atomic force microscopy (AFM) analysis results showed that the mean roughness (Ra) of the SAMs decreased with increasing the alkyl chain length. The tribological properties of the SAMs sliding against Al2O3 ball were evaluated on an UMT-2 tribometer, and the worn surfaces of the samples were analyzed by means of Nano Scratch Tester and surface profilometry. It was found that lowest friction coefficient and smallest width of wear were achieved with the SAMs of C12 alkyl chain (C12-SAM). The superior friction reduction and wear resistance of the SAMs in comparison with the bare silicon substrate are attributed to good adhesion of the self-assembled films to the substrate, especially the C12-SAM with desirable alkyl chain length.

Optimization of pentacene double floating gate memories based on charge injection regulated by SAM functionalization

Directory of Open Access Journals (Sweden)

S. Li

2018-02-01

Full Text Available Pentacene based double nano-floating gate memories (NFGM by using gold nanoparticles (Au NPs and reduced graphene oxide (rGO sheets as charge trapping layers are prepared and demonstrated. Particularly, the NFGM chemically treated by 2,3,4,5,6-pentafluorobenzenethiol (PFBT self-assembled monolayers (SAM exhibits excellent memory performances, including high mobility of 0.23 cm2V-1s-1, the large memory window of 51 V, and the stable retention property more than 108 s. Comparing the performances of NFGM without treating with PFBT SAM, the improving performances of the memory devices by SAM modification are explained by the increase of charge injection, which could be further investigated by XPS and UPS. In particular, the results highlight the utility of SAM modulations and controlling of charge transport in the development of organic transistor memories.

Optimization of pentacene double floating gate memories based on charge injection regulated by SAM functionalization

Science.gov (United States)

Li, S.; Guérin, D.; Lenfant, S.; Lmimouni, K.

2018-02-01

Pentacene based double nano-floating gate memories (NFGM) by using gold nanoparticles (Au NPs) and reduced graphene oxide (rGO) sheets as charge trapping layers are prepared and demonstrated. Particularly, the NFGM chemically treated by 2,3,4,5,6-pentafluorobenzenethiol (PFBT) self-assembled monolayers (SAM) exhibits excellent memory performances, including high mobility of 0.23 cm2V-1s-1, the large memory window of 51 V, and the stable retention property more than 108 s. Comparing the performances of NFGM without treating with PFBT SAM, the improving performances of the memory devices by SAM modification are explained by the increase of charge injection, which could be further investigated by XPS and UPS. In particular, the results highlight the utility of SAM modulations and controlling of charge transport in the development of organic transistor memories.

Bringing a Chemical Laboratory Named Sam to Mars on the 2011 Curiosity Rover

Science.gov (United States)

Mahaffy, P. R.; Bleacher, L.; Jones, A.; Conrad, P. G.; Cabane, M.; Webster, C. R.; Atreya, S. A.; Manning, H.

2010-01-01

An important goal of upcoming missions to Mars is to understand if life could have developed there. The task of the Sample Analysis at Mars (SAM) suite of instruments [1] and the other Curiosity investigations [2] is to move us steadily toward that goal with an assessment of the habitability of our neighboring planet through a series of chemical and geological measurements. SAM is designed to search for organic compounds and inorganic volatiles and measure isotope ratios. Other instruments on Curiosity will provide elemental analysis and identify minerals. SAM will analyze both atmospheric samples and gases evolved from powdered rocks that may have formed billions of years ago with Curiosity providing access to interesting sites scouted by orbiting cameras and spectrometers.

General Dialdehyde Click Chemistry for Amine Bioconjugation.

Science.gov (United States)

Elahipanah, Sina; O'Brien, Paul J; Rogozhnikov, Dmitry; Yousaf, Muhammad N

2017-05-17

The development of methods for conjugating a range of molecules to primary amine functional groups has revolutionized the fields of chemistry, biology, and material science. The primary amine is a key functional group and one of the most important nucleophiles and bases used in all of synthetic chemistry. Therefore, tremendous interest in the synthesis of molecules containing primary amines and strategies to devise chemical reactions to react with primary amines has been at the core of chemical research. In particular, primary amines are a ubiquitous functional group found in biological systems as free amino acids, as key side chain lysines in proteins, and in signaling molecules and metabolites and are also present in many natural product classes. Due to its abundance, the primary amine is the most convenient functional group handle in molecules for ligation to other molecules for a broad range of applications that impact all scientific fields. Because of the primary amine's central importance in synthetic chemistry, acid-base chemistry, redox chemistry, and biology, many methods have been developed to efficiently react with primary amines, including activated carboxylic acids, isothiocyanates, Michael addition type systems, and reaction with ketones or aldehydes followed by in situ reductive amination. Herein, we introduce a new traceless, high-yield, fast click-chemistry method based on the rapid and efficient trapping of amine groups via a functionalized dialdehyde group. The click reaction occurs in mild conditions in organic solvents or aqueous media and proceeds in high yield, and the starting dialdehyde reagent and resulting dialdehyde click conjugates are stable. Moreover, no catalyst or dialdehyde-activating group is required, and the only byproduct is water. The initial dialdehyde and the resulting conjugate are both straightforward to characterize, and the reaction proceeds with high atom economy. To demonstrate the broad scope of this new click

The Azomethine Ylide Route to Amine C–H Functionalization: Redox-Versions of Classic Reactions and a Pathway to New Transformations

Science.gov (United States)

2016-01-01

Conspectus Redox-neutral methods for the functionalization of amine α-C–H bonds are inherently efficient because they avoid external oxidants and reductants and often do not generate unwanted byproducts. However, most of the current methods for amine α-C–H bond functionalization are oxidative in nature. While the most efficient variants utilize atmospheric oxygen as the terminal oxidant, many such transformations require the use of expensive or toxic oxidants, often coupled with the need for transition metal catalysts. Redox-neutral amine α-functionalizations that involve intramolecular hydride transfer steps provide viable alternatives to certain oxidative reactions. These processes have been known for some time and are particularly well suited for tertiary amine substrates. A mechanistically distinct strategy for secondary amines has emerged only recently, despite sharing common features with a range of classic organic transformations. Among those are such widely used reactions as the Strecker, Mannich, Pictet–Spengler, and Kabachnik–Fields reactions, Friedel–Crafts alkylations, and iminium alkynylations. In these classic processes, condensation of a secondary amine with an aldehyde (or a ketone) typically leads to the formation of an intermediate iminium ion, which is subsequently attacked by a nucleophile. The corresponding redox-versions of these transformations utilize identical starting materials but incorporate an isomerization step that enables α-C–H bond functionalization. Intramolecular versions of these reactions include redox-neutral amine α-amination, α-oxygenation, and α-sulfenylation. In all cases, a reductive N-alkylation is effectively combined with an oxidative α-functionalization, generating water as the only byproduct. Reactions are promoted by simple carboxylic acids and in some cases require no additives. Azomethine ylides, dipolar species whose usage is predominantly in [3 + 2] cycloadditions and other pericyclic

The azomethine ylide route to amine C-H functionalization: redox-versions of classic reactions and a pathway to new transformations.

Science.gov (United States)

Seidel, Daniel

2015-02-17

Conspectus Redox-neutral methods for the functionalization of amine α-C-H bonds are inherently efficient because they avoid external oxidants and reductants and often do not generate unwanted byproducts. However, most of the current methods for amine α-C-H bond functionalization are oxidative in nature. While the most efficient variants utilize atmospheric oxygen as the terminal oxidant, many such transformations require the use of expensive or toxic oxidants, often coupled with the need for transition metal catalysts. Redox-neutral amine α-functionalizations that involve intramolecular hydride transfer steps provide viable alternatives to certain oxidative reactions. These processes have been known for some time and are particularly well suited for tertiary amine substrates. A mechanistically distinct strategy for secondary amines has emerged only recently, despite sharing common features with a range of classic organic transformations. Among those are such widely used reactions as the Strecker, Mannich, Pictet-Spengler, and Kabachnik-Fields reactions, Friedel-Crafts alkylations, and iminium alkynylations. In these classic processes, condensation of a secondary amine with an aldehyde (or a ketone) typically leads to the formation of an intermediate iminium ion, which is subsequently attacked by a nucleophile. The corresponding redox-versions of these transformations utilize identical starting materials but incorporate an isomerization step that enables α-C-H bond functionalization. Intramolecular versions of these reactions include redox-neutral amine α-amination, α-oxygenation, and α-sulfenylation. In all cases, a reductive N-alkylation is effectively combined with an oxidative α-functionalization, generating water as the only byproduct. Reactions are promoted by simple carboxylic acids and in some cases require no additives. Azomethine ylides, dipolar species whose usage is predominantly in [3 + 2] cycloadditions and other pericyclic processes, have been

A magnesium-induced triplex pre-organizes the SAM-II riboswitch.

Directory of Open Access Journals (Sweden)

Susmita Roy

2017-03-01

Full Text Available Our 13C- and 1H-chemical exchange saturation transfer (CEST experiments previously revealed a dynamic exchange between partially closed and open conformations of the SAM-II riboswitch in the absence of ligand. Here, all-atom structure-based molecular simulations, with the electrostatic effects of Manning counter-ion condensation and explicit magnesium ions are employed to calculate the folding free energy landscape of the SAM-II riboswitch. We use this analysis to predict that magnesium ions remodel the landscape, shifting the equilibrium away from the extended, partially unfolded state towards a compact, pre-organized conformation that resembles the ligand-bound state. Our CEST and SAXS experiments, at different magnesium ion concentrations, quantitatively confirm our simulation results, demonstrating that magnesium ions induce collapse and pre-organization. Agreement between theory and experiment bolsters microscopic interpretation of our simulations, which shows that triplex formation between helix P2b and loop L1 is highly sensitive to magnesium and plays a key role in pre-organization. Pre-organization of the SAM-II riboswitch allows rapid detection of ligand with high selectivity, which is important for biological function.

Simulated SAM A-scans on multilayer MEMS components

DEFF Research Database (Denmark)

Janting, Jakob; Petersen, Dirch Hjorth; Greisen, Christoffer

2002-01-01

A spreadsheet program for simulation of Scanning Acoustic Microscopy (SAM) A-scans on multilayer structures has been developed. Using this program, structure variations in samples can be analysed better. Further samples can be prepared to get optimal signal for enhanced failure and materials...

Biogenic amines degradation by microorganisms isolated from cheese

Directory of Open Access Journals (Sweden)

Irena Butor

2017-01-01

Full Text Available The aim of this study was the isolation and characterization of microorganisms able to degrade biogenic amines and their identification. Individual microorganisms were obtained by isolation from commercially available foodstuffs and food produced in the technological laboratories of Faculty of Technology, Tomas Bata University in Zlín and subsequently identified by MALDI-TOF MS. The results of MALDI-TOF MS identification were verified by 16S rRNA sequenation. In this work was studied the ability of 5 bacterial strains positive to biogenic amines degradation isolated from dairy products to decrease biogenic amines content in vitro and quantified reduction in the concentration of biogenic amines tryptamine, β-phenylethylamine, putrescine, cadaverine, histamine and tyramine. The level of degradation (decrease of biogenic amines was determined on the base of the ability to grow in media with biogenic amines as the sole source carbon and nitrogen. The isolated strains with the ability of degradation of one or more biogenic amines were cultured in medium supplemented with relevant biogenic amines, the media derivatized with dansyl chloride and these amines separated by HPLC at a wavelength of 254 nm. From five tested strains identified as Bacillus subtilis, Bacillus pumilus, Enterobacter cloacae, Rhizobium radiobacter and Acinetobacter pitii, isolated from gouda type cheese, the greatest ability of degradation was observed in Bacillus subtilis, which was capable to degrade almost all amount of histamine, cadaverine and putrescine. Other four strains showed a lower rate of degradation than Bacillus subtilis, but the ability to degrade biogenic amines with these microorganisms was still significant.

Sam68 promotes Schwann cell proliferation by enhancing the PI3K/Akt pathway and acts on regeneration after sciatic nerve crush

Energy Technology Data Exchange (ETDEWEB)

Wu, Weijie, E-mail: 459586768@qq.com; Liu, Yuxi, E-mail: 924013616@qq.com; Wang, Youhua, E-mail: wyouhua1516@163.com

2016-05-13

Sam68 (Src-associated in mitosis of 68 kD), a KH domain RNA-binding protein, is not only important in signaling transduction cascades, but crucial in a variety of cellular processes. Sam68 is reported to be involved in the phospoinositide3-kinase (PI3K) and nuclear factor-kappa B (NF-κB) signaling pathways, and it is closely associated with cell proliferation, RNA metabolism, and tumor progression. However, we know little about the role of Sam68 during peripheral nervous system injury and regeneration. In this study, we investigated the expression of Sam68 and its biological significances in sciatic nerve crush. Interestingly, we found Sam68 had a co-localization with S100 (Schwann cell marker). Moreover, after crush, Sam68 had a spatiotemporal protein expression, which was in parallel with proliferation cell nuclear antigen (PCNA). In vitro, we also observed increased expression of Sam68 during the process of TNF-α-induced Schwann cell proliferation model. Besides, flow cytometry analyses, CCK-8, and EDU were all performed with the purpose of investigating the role of Sam68 in the regulation of Schwann cell proliferation. Even more importantly, we discovered that Sam68 could enhance the phosphorylation of Akt while LY294002 (a PI3K inhibitor) obviously reversed Sam68-induced cell proliferation. Finally, we detected the variance during regeneration progress through the rat walk footprint test. In summary, all these evidences demonstrated that Sam68 might participate in Schwann cell proliferation partially via PI3K/Akt pathway and also regulate regeneration after sciatic nerve crush. -- Highlights: •The dynamic changes and location of Sam68 after sciatic nerve crush. •Sam68 promoted Schwann cell proliferation via PI3K/Akt pathway. •Sam68 modulated functional recovery after sciatic nerve crush.

Sam68 promotes Schwann cell proliferation by enhancing the PI3K/Akt pathway and acts on regeneration after sciatic nerve crush

International Nuclear Information System (INIS)

Wu, Weijie; Liu, Yuxi; Wang, Youhua

2016-01-01

Sam68 (Src-associated in mitosis of 68 kD), a KH domain RNA-binding protein, is not only important in signaling transduction cascades, but crucial in a variety of cellular processes. Sam68 is reported to be involved in the phospoinositide3-kinase (PI3K) and nuclear factor-kappa B (NF-κB) signaling pathways, and it is closely associated with cell proliferation, RNA metabolism, and tumor progression. However, we know little about the role of Sam68 during peripheral nervous system injury and regeneration. In this study, we investigated the expression of Sam68 and its biological significances in sciatic nerve crush. Interestingly, we found Sam68 had a co-localization with S100 (Schwann cell marker). Moreover, after crush, Sam68 had a spatiotemporal protein expression, which was in parallel with proliferation cell nuclear antigen (PCNA). In vitro, we also observed increased expression of Sam68 during the process of TNF-α-induced Schwann cell proliferation model. Besides, flow cytometry analyses, CCK-8, and EDU were all performed with the purpose of investigating the role of Sam68 in the regulation of Schwann cell proliferation. Even more importantly, we discovered that Sam68 could enhance the phosphorylation of Akt while LY294002 (a PI3K inhibitor) obviously reversed Sam68-induced cell proliferation. Finally, we detected the variance during regeneration progress through the rat walk footprint test. In summary, all these evidences demonstrated that Sam68 might participate in Schwann cell proliferation partially via PI3K/Akt pathway and also regulate regeneration after sciatic nerve crush. -- Highlights: •The dynamic changes and location of Sam68 after sciatic nerve crush. •Sam68 promoted Schwann cell proliferation via PI3K/Akt pathway. •Sam68 modulated functional recovery after sciatic nerve crush.

Metabolism and Biomarkers of Heterocyclic Aromatic Amines in Molecular Epidemiology Studies: Lessons Learned from Aromatic Amines

Science.gov (United States)

2011-01-01

Aromatic amines and heterocyclic aromatic amines (HAAs) are structurally related classes of carcinogens that are formed during the combustion of tobacco or during the high-temperature cooking of meats. Both classes of procarcinogens undergo metabolic activation by N-hydroxylation of the exocyclic amine group, to produce a common proposed intermediate, the arylnitrenium ion, which is the critical metabolite implicated in toxicity and DNA damage. However, the biochemistry and chemical properties of these compounds are distinct and different biomarkers of aromatic amines and HAAs have been developed for human biomonitoring studies. Hemoglobin adducts have been extensively used as biomarkers to monitor occupational and environmental exposures to a number of aromatic amines; however, HAAs do not form hemoglobin adducts at appreciable levels and other biomarkers have been sought. A number of epidemiologic studies that have investigated dietary consumption of well-done meat in relation to various tumor sites reported a positive association between cancer risk and well-done meat consumption, although some studies have shown no associations between well-done meat and cancer risk. A major limiting factor in most epidemiological studies is the uncertainty in quantitative estimates of chronic exposure to HAAs and, thus, the association of HAAs formed in cooked meat and cancer risk has been difficult to establish. There is a critical need to establish long-term biomarkers of HAAs that can be implemented in molecular epidemioIogy studies. In this review article, we highlight and contrast the biochemistry of several prototypical carcinogenic aromatic amines and HAAs to which humans are chronically exposed. The biochemical properties and the impact of polymorphisms of the major xenobiotic-metabolizing enzymes on the biological effects of these chemicals are examined. Lastly, the analytical approaches that have been successfully employed to biomonitor aromatic amines and HAAs, and

Background of SAM atom-fraction profiles

International Nuclear Information System (INIS)

Ernst, Frank

2017-01-01

Atom-fraction profiles acquired by SAM (scanning Auger microprobe) have important applications, e.g. in the context of alloy surface engineering by infusion of carbon or nitrogen through the alloy surface. However, such profiles often exhibit an artifact in form of a background with a level that anti-correlates with the local atom fraction. This article presents a theory explaining this phenomenon as a consequence of the way in which random noise in the spectrum propagates into the discretized differentiated spectrum that is used for quantification. The resulting model of “energy channel statistics” leads to a useful semi-quantitative background reduction procedure, which is validated by applying it to simulated data. Subsequently, the procedure is applied to an example of experimental SAM data. The analysis leads to conclusions regarding optimum experimental acquisition conditions. The proposed method of background reduction is based on general principles and should be useful for a broad variety of applications. - Highlights: • Atom-fraction–depth profiles of carbon measured by scanning Auger microprobe • Strong background, varies with local carbon concentration. • Needs correction e.g. for quantitative comparison with simulations • Quantitative theory explains background. • Provides background removal strategy and practical advice for acquisition

Background of SAM atom-fraction profiles

Energy Technology Data Exchange (ETDEWEB)

Ernst, Frank

2017-03-15

Atom-fraction profiles acquired by SAM (scanning Auger microprobe) have important applications, e.g. in the context of alloy surface engineering by infusion of carbon or nitrogen through the alloy surface. However, such profiles often exhibit an artifact in form of a background with a level that anti-correlates with the local atom fraction. This article presents a theory explaining this phenomenon as a consequence of the way in which random noise in the spectrum propagates into the discretized differentiated spectrum that is used for quantification. The resulting model of “energy channel statistics” leads to a useful semi-quantitative background reduction procedure, which is validated by applying it to simulated data. Subsequently, the procedure is applied to an example of experimental SAM data. The analysis leads to conclusions regarding optimum experimental acquisition conditions. The proposed method of background reduction is based on general principles and should be useful for a broad variety of applications. - Highlights: • Atom-fraction–depth profiles of carbon measured by scanning Auger microprobe • Strong background, varies with local carbon concentration. • Needs correction e.g. for quantitative comparison with simulations • Quantitative theory explains background. • Provides background removal strategy and practical advice for acquisition.

Amine promoted, metal enhanced degradation of Mirex under high temperature conditions

Energy Technology Data Exchange (ETDEWEB)

Jallad, Karim N. [American University of Sharjah, Department of Chemistry, P.O. Box 26666, Sharjah (United Arab Emirates)]. E-mail: kjallad@runbox.com; Lynn, Bert C. [University of Kentucky, Department of Chemistry, Lexington, KY 40506-055 (United States); Alley, Earl G. [Mississippi State University, Department of Chemistry, MS State, MS 39762 (United States)

2006-07-31

In this study, zero-valent metal dehalogenation of mirex was conducted with amine solvents at high temperatures. Mirex was treated with excess amine in sealed glass tube reactors under nitrogen. The amines used were n-butyl amine (l), ethyl amine (l), dimethyl amine (g), diethyl amine (l), triethyl amine (l), trimethyl amine (g) and ammonia (g). The metals used were copper, zinc, magnesium, aluminum and calcium. The most suitable amine solvent and metal were selected by running a series of reactions with different amines and different zero-valent metals, in order to optimize the conditions under which complete degradation of mirex takes place. These dehalogenation reactions illustrated the role of zero-valent metals as reductants, whereas the amine solvents acted as proton donors. In this study, we report that mirex was completely degraded with diethyl amine (l) in the presence of copper at 100 deg. C and the hydrogenated products accounted for more than 94 of the degraded mirex.

A versatile family of degradable non-viral gene carriers based on hyperbranched poly(ester amine)s

NARCIS (Netherlands)

Zhong, Zhiyuan; Song, Y.; Engbersen, Johannes F.J.; Lok, Martin C.; Hennink, Wim E.; Feijen, Jan

2005-01-01

A variety of degradable hyperbranched poly(ester amine)s containing primary, secondary and tertiary amino groups, were synthesized and evaluated as non-viral gene carriers. The polymers were obtained in high yields through a Michael-type conjugate addition of diacrylate monomers with trifunctional

Room-Temperature, Ambient-Pressure Chemical Synthesis of Amine-Functionalized Hierarchical Carbon-Sulfur Composites for Lithium-Sulfur Battery Cathodes.

Science.gov (United States)

Chae, Changju; Kim, Jinmin; Kim, Ju Young; Ji, Seulgi; Lee, Sun Sook; Kang, Yongku; Choi, Youngmin; Suk, Jungdon; Jeong, Sunho

2018-02-07

Recently, the achievement of newly designed carbon-sulfur composite materials has attracted a tremendous amount of attention as high-performance cathode materials for lithium-sulfur batteries. To date, sulfur materials have been generally synthesized by a sublimation technique in sealed containers. This is a well-developed technique for the synthesizing of well-ordered sulfur materials, but it is limited when used to scale up synthetic procedures for practical applications. In this study, we suggest an easily scalable, room-temperature/ambient-pressure chemical pathway for the synthesis of highly functioning cathode materials using electrostatically assembled, amine-terminated carbon materials. It is demonstrated that stable cycling performance outcomes are achievable with a capacity of 730 mAhg -1 at a current density of 1 C with good cycling stability by a virtue of the characteristic chemical/physical properties (a high conductivity for efficient charge conduction and the presence of a number of amine groups that can interact with sulfur atoms during electrochemical reactions) of composite materials. The critical roles of conductive carbon moieties and amine functional groups inside composite materials are clarified with combinatorial analyses by X-ray photoelectron spectroscopy, cyclic voltammetry, and electrochemical impedance spectroscopy.

Blocking an N-terminal acetylation–dependent protein interaction inhibits an E3 ligase

Energy Technology Data Exchange (ETDEWEB)

Scott, Daniel C.; Hammill, Jared T.; Min, Jaeki; Rhee, David Y.; Connelly, Michele; Sviderskiy, Vladislav O.; Bhasin, Deepak; Chen, Yizhe; Ong, Su-Sien; Chai, Sergio C.; Goktug, Asli N.; Huang, Guochang; Monda, Julie K.; Low, Jonathan; Kim, Ho Shin; Paulo, Joao A.; Cannon, Joe R.; Shelat, Anang A.; Chen, Taosheng; Kelsall, Ian R.; Alpi, Arno F.; Pagala, Vishwajeeth; Wang, Xusheng; Peng, Junmin; Singh , Bhuvanesh; Harper, J. Wade; Schulman, Brenda A.; Guy, R. Kip (MSKCC); (Dundee); (SJCH); (Harvard-Med); (MXPL)

2017-06-05

N-terminal acetylation is an abundant modification influencing protein functions. Because ~80% of mammalian cytosolic proteins are N-terminally acetylated, this modification is potentially an untapped target for chemical control of their functions. Structural studies have revealed that, like lysine acetylation, N-terminal acetylation converts a positively charged amine into a hydrophobic handle that mediates protein interactions; hence, this modification may be a druggable target. We report the development of chemical probes targeting the N-terminal acetylation–dependent interaction between an E2 conjugating enzyme (UBE2M or UBC12) and DCN1 (DCUN1D1), a subunit of a multiprotein E3 ligase for the ubiquitin-like protein NEDD8. The inhibitors are highly selective with respect to other protein acetyl-amide–binding sites, inhibit NEDD8 ligation in vitro and in cells, and suppress anchorage-independent growth of a cell line with DCN1 amplification. Overall, our data demonstrate that N-terminal acetyl-dependent protein interactions are druggable targets and provide insights into targeting multiprotein E2–E3 ligases.

Synthesis and bioelectrochemical behavior of aromatic amines.

Science.gov (United States)

Shabbir, Muhammad; Akhter, Zareen; Ahmad, Iqbal; Ahmed, Safeer; Bolte, Michael; McKee, Vickie

2017-12-01

Four aromatic amines 1-amino-4-phenoxybenzene (A 1 ), 4-(4-aminophenyloxy) biphenyl (A 2 ), 1-(4-aminophenoxy) naphthalene (A 3 ) and 2-(4-aminophenoxy) naphthalene (A 4 ) were synthesized and characterized by elemental, spectroscopic (FTIR, NMR), mass spectrometric and single crystal X-ray diffraction methods. The compounds crystallized in monoclinic crystal system with space group P2 1 . Intermolecular hydrogen bonds were observed between the amine group and amine/ether acceptors of neighboring molecules. Electrochemical investigations were done using cyclic voltammetry (CV), square wave voltammetry (SWV) and differential pulse voltammetry (DPV). CV studies showed that oxidation of aromatic amines takes place at about 0.9 V (vs. Ag/AgCl) and the electron transfer (ET) process has irreversible nature. After first scan reactive intermediate were generated electrochemically and some other cathodic and anodic peaks also appeared in the succeeding scans. DPV study revealed that ET process is accompanied by one electron. DNA binding study of aromatic amines was performed by CV and UV-visible spectroscopy. These investigations revealed groove binding mode of interaction of aromatic amines with DNA. Copyright © 2017 Elsevier Inc. All rights reserved.

Development of the criticality capability for the SAM-CE Monte Carlo System

International Nuclear Information System (INIS)

Lichtenstein, H.; Troubetzkoy, E.; Steinberg, H.; Cohen, M.O.

1979-04-01

A criticality capabilty has been developed and implemented in the SAM-CE Monte Carlo system. The data processing component, SAM-X, preserves, to any required accuracy, the data quality inherent in the ENDF/B library. The generated data is Doppler-broadened and includes (where applicable) probability tables for the unresolved resonance range, and thermal-scattering law data. Curves of several total and partial cross sections are generated and displayed. The Monte Carlo component, SAM-F, includes several eigenvalue estimators and variance reduction schemes. Stratification was found to effect significant improvement in calculational efficiency, but the usefulness of importance sampling is marginal in criticality problems. The entire system has been installed at BNL, for the analysis of TRX benchmarks. The TRX-1 and TRX-2 cell calculations have been performed, with estimated eigenvalues of 1.1751 +- 0.0016 and 1.1605 +- .0015, respectively. These results are shown to be statistically consistent with other sources

Amine Swingbed Payload Project Management

Science.gov (United States)

Walsch, Mary; Curley, Su

2013-01-01

The International Space Station (ISS) has been designed as a laboratory for demonstrating technologies in a microgravity environment, benefitting exploration programs by reducing the overall risk of implementing such technologies in new spacecraft. At the beginning of fiscal year 2010, the ISS program manager requested that the amine-based, pressure-swing carbon dioxide and humidity absorption technology (designed by Hamilton Sundstrand, baselined for the Orion Multi-Purpose Crew Vehicle, and tested at the Johnson Space Center in relevant environments, including with humans, since 2005) be developed into a payload for ISS Utilization. In addition to evaluating the amine technology in a flight environment before the first launch of the Orion vehicle, the ISS program wanted to determine the capability of the amine technology to remove carbon dioxide from the ISS cabin environment at the metabolic rate of the full 6 ]person crew. Because the amine technology vents the absorbed carbon dioxide and water vapor to space vacuum (open loop), additional hardware needed to be developed to minimize the amount of air and water resources lost overboard. Additionally, the payload system would be launched on two separate Space Shuttle flights, with the heart of the payload-the swingbed unit itself-launching a full year before the remainder of the payload. This paper discusses the project management and challenges of developing the amine swingbed payload in order to accomplish the technology objectives of both the open -loop Orion application as well as the closed-loop ISS application.

Raman mapping and in situ SERS spectroelectrochemical studies of 6-mercaptopurine SAMs on the gold electrode.

Science.gov (United States)

Yang, Haifeng; Liu, Yanli; Liu, Zhimin; Yang, Yu; Jiang, Jianhui; Zhang, Zongrang; Shen, Guoli; Yu, Ruqin

2005-02-24

The self-assembled monolayers (SAMs) of 6-mercaptopurine (6MP) were formed at the roughened polycrystalline gold surfaces in acid and alkaline media. The time-dependent Raman mapping spectral analysis in conjunction with the quantum calculations for the vibrational modes using ab initio BLYP/6-31G method suggested that both of the resulted 6MP SAMs adopted the same adsorption mode through the S atom of pyrimidine moiety and the N7 atom of the imidazole moiety anchoring the gold surface in a vertical way. The in situ surface-enhanced Raman scattering spectroelectrochemical experiment was conducted to examine the stability of the SAMs at various bias potentials. It was found that the detaching process of the 6MP SAMs from the surface involved one electron reduction as the voltage was applied at ca. 0.7 V vs a standard calomel electrode.

Tandem catalytic allylic amination and [2,3]-Stevens rearrangement of tertiary amines.

Science.gov (United States)

Soheili, Arash; Tambar, Uttam K

2011-08-24

We have developed a catalytic allylic amination involving tertiary aminoesters and allylcarbonates, which is the first example of the use of tertiary amines as intermolecular nucleophiles in metal-catalyzed allylic substitution chemistry. This process is employed in a tandem ammonium ylide generation/[2,3]-rearrangement reaction, which formally represents a palladium-catalyzed Stevens rearrangement. Low catalyst loadings and mild reaction conditions are compatible with an unprecedented substrate scope for the ammonium ylide functionality, and products are generated in high yields and diastereoselectivities. Mechanistic studies suggested the reversible formation of an ammonium intermediate.

Orientation of 6-mercaptopurine SAMs at the silver electrode as studied by Raman mapping and in situ SERS.

Science.gov (United States)

Chu, Hui; Yang, Haifeng; Huan, Shuangyan; Shen, Guoli; Yu, Ruqin

2006-03-23

Self-assembled monolayers (SAMs) of 6-mercaptopurine (6MP) on a silver electrode in acid and alkaline media were investigated by a combination protocol of the SERS technique with Raman mapping, and it was found that the adsorption mode of 6MP SAMs changed with the pH value of the environment. Quantum calculations for the vibrational mode were performed by the BLYP/6-31G method. 6MP was adsorbed on the silver electrode with a tilted orientation via S, N1, and N7 atoms in acid medium, while the SAMs adopted head-on adsorption modes with the S atom and the N1 atom anchoring the silver surface in alkaline medium. However, 6MP SAMs turned to the same upright orientation on the electrode through the S and N7 atoms when either acid or basic solution was removed. Stability of 6MP SAMs was observed by in situ SERS spectroelectrochemical measurements. The results reveal that the desorption potentials of 6MP SAMs formed under acid and alkaline conditions from the Ag electrode were at ca. -1.3 V and -1.6 V vs SCE, respectively.

The SAM, not the electrodes, dominates charge transport in metal-monolayer//Ga2O3/gallium-indium eutectic junctions.

Science.gov (United States)

Reus, William F; Thuo, Martin M; Shapiro, Nathan D; Nijhuis, Christian A; Whitesides, George M

2012-06-26

The liquid-metal eutectic of gallium and indium (EGaIn) is a useful electrode for making soft electrical contacts to self-assembled monolayers (SAMs). This electrode has, however, one feature whose effect on charge transport has been incompletely understood: a thin (approximately 0.7 nm) film-consisting primarily of Ga(2)O(3)-that covers its surface when in contact with air. SAMs that rectify current have been measured using this electrode in Ag(TS)-SAM//Ga(2)O(3)/EGaIn (where Ag(TS) = template-stripped Ag surface) junctions. This paper organizes evidence, both published and unpublished, showing that the molecular structure of the SAM (specifically, the presence of an accessible molecular orbital asymmetrically located within the SAM), not the difference between the electrodes or the characteristics of the Ga(2)O(3) film, causes the observed rectification. By examining and ruling out potential mechanisms of rectification that rely either on the Ga(2)O(3) film or on the asymmetry of the electrodes, this paper demonstrates that the structure of the SAM dominates charge transport through Ag(TS)-SAM//Ga(2)O(3)/EGaIn junctions, and that the electrical characteristics of the Ga(2)O(3) film have a negligible effect on these measurements.

Electron transfer kinetics of cytochrome c immobilized on a phenolic terminated thiol self assembled monolayer determined by scanning electrochemical microscopy

International Nuclear Information System (INIS)

Alizadeh, Vali; Mousavi, Mir Fazlollah; Mehrgardi, Masoud Ayatollahi; Kazemi, Sayed Habib; Sharghi, Hashem

2011-01-01

Highlights: → Preparing a thiolated phenolic self-assembled monolayer surface (SAM). → Application of this SAM to immobilize cytochrome C. → Scanning electrochemical microscopy used for these studies. → Determination of both tunneling electron transfer and bimolecular rate constants between the immobilized protein-substrate and probe. - Abstract: In the present manuscript, the electrochemical behavior of cytochrome c (cyt-c) immobilized onto a phenolic terminated self assembled monolayer (SAM) on a gold electrode is investigated using cyclic voltammetry (CV) and scanning electrochemical microscopy (SECM). The tunneling electron transfer (ET) rate constant between the immobilized protein and the underlying electrode surface, and also the bimolecular ET rate constant between the immobilized protein and a probe has been obtained using approach curves that were obtained by SECM. The approach curves were recorded at different substrate overpotentials in the presence of various concentrations of ferrocyanide as a probe and various surface concentrations of cyt-c; then the standard tunneling ET and bimolecular rate constants are obtained as 3.4 ± 0.3 s -1 and (2.0 ± 0.5) x 10 7 cm 3 mol -1 s -1 , respectively.

Electron transfer kinetics of cytochrome c immobilized on a phenolic terminated thiol self assembled monolayer determined by scanning electrochemical microscopy

Energy Technology Data Exchange (ETDEWEB)

Alizadeh, Vali [Department of Chemistry, Tarbiat Modares University, P.O. Box 14115-175, Tehran (Iran, Islamic Republic of); Mousavi, Mir Fazlollah, E-mail: mousavim@modares.ac.ir [Department of Chemistry, Tarbiat Modares University, P.O. Box 14115-175, Tehran (Iran, Islamic Republic of); Mehrgardi, Masoud Ayatollahi [Department of Chemistry, University of Isfahan, Isfahan (Iran, Islamic Republic of); Kazemi, Sayed Habib [Department of Chemistry, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan (Iran, Islamic Republic of); Sharghi, Hashem [Department of Chemistry, Shiraz University, Shiraz (Iran, Islamic Republic of)

2011-07-01

Highlights: > Preparing a thiolated phenolic self-assembled monolayer surface (SAM). > Application of this SAM to immobilize cytochrome C. > Scanning electrochemical microscopy used for these studies. > Determination of both tunneling electron transfer and bimolecular rate constants between the immobilized protein-substrate and probe. - Abstract: In the present manuscript, the electrochemical behavior of cytochrome c (cyt-c) immobilized onto a phenolic terminated self assembled monolayer (SAM) on a gold electrode is investigated using cyclic voltammetry (CV) and scanning electrochemical microscopy (SECM). The tunneling electron transfer (ET) rate constant between the immobilized protein and the underlying electrode surface, and also the bimolecular ET rate constant between the immobilized protein and a probe has been obtained using approach curves that were obtained by SECM. The approach curves were recorded at different substrate overpotentials in the presence of various concentrations of ferrocyanide as a probe and various surface concentrations of cyt-c; then the standard tunneling ET and bimolecular rate constants are obtained as 3.4 {+-} 0.3 s{sup -1} and (2.0 {+-} 0.5) x 10{sup 7} cm{sup 3} mol{sup -1} s{sup -1}, respectively.

CE-SAM: a conversational interface for ISR mission support

Science.gov (United States)

Pizzocaro, Diego; Parizas, Christos; Preece, Alun; Braines, Dave; Mott, David; Bakdash, Jonathan Z.

2013-05-01

There is considerable interest in natural language conversational interfaces. These allow for complex user interactions with systems, such as fulfilling information requirements in dynamic environments, without requiring extensive training or a technical background (e.g. in formal query languages or schemas). To leverage the advantages of conversational interactions we propose CE-SAM (Controlled English Sensor Assignment to Missions), a system that guides users through refining and satisfying their information needs in the context of Intelligence, Surveillance, and Reconnaissance (ISR) operations. The rapidly-increasing availability of sensing assets and other information sources poses substantial challenges to effective ISR resource management. In a coalition context, the problem is even more complex, because assets may be "owned" by different partners. We show how CE-SAM allows a user to refine and relate their ISR information needs to pre-existing concepts in an ISR knowledge base, via conversational interaction implemented on a tablet device. The knowledge base is represented using Controlled English (CE) - a form of controlled natural language that is both human-readable and machine processable (i.e. can be used to implement automated reasoning). Users interact with the CE-SAM conversational interface using natural language, which the system converts to CE for feeding-back to the user for confirmation (e.g. to reduce misunderstanding). We show that this process not only allows users to access the assets that can support their mission needs, but also assists them in extending the CE knowledge base with new concepts.

Extraction of sulphates by long chain amines

International Nuclear Information System (INIS)

Boirie, Ch.

1959-05-01

The extraction of sulphuric acid by long chain amines in organic solution has been studied with a view to determining the value of the stability constants of the amine sulphates and bi-sulphates formed. We have concentrated chiefly on uranium sulphate and thorium sulphate. The formulae of the complexes extractable with amines have been established, as well as the corresponding dissociation constants. We have observed that for uranium sulphate the formula of the complex depends only on the nature of the amine, whereas for thorium this formula varies with the amine structure. From the formulae determined and the value of the constants calculated, we have been able to establish the best conditions for uranium and thorium extraction and also for a separation of these two elements. Finally we propose an application of this study to the determination of uranium in ores, where the separation of uranium by this method is particularly easy and complete. (author) [fr

TRX and UO2 criticality benchmarks with SAM-CE

International Nuclear Information System (INIS)

Beer, M.; Troubetzkoy, E.S.; Lichtenstein, H.; Rose, P.F.

1980-01-01

A set of thermal reactor benchmark calculations with SAM-CE which have been conducted at both MAGI and at BNL are described. Their purpose was both validation of the SAM-CE reactor eigenvalue capability developed by MAGI and a substantial contribution to the data testing of both ENDF/B-IV and ENDF/B-V libraries. This experience also resulted in increased calculational efficiency of the code and an example is given. The benchmark analysis included the TRX-1 infinite cell using both ENDF/B-IV and ENDF/B-V cross section sets and calculations using ENDF/B-IV of the TRX-1 full core and TRX-2 cell. BAPL-UO2-1 calculations were conducted for the cell using both ENDF/B-IV and ENDF/B-V and for the full core with ENDF/B-V

Redox reactions of Cu(II)-amine complexes in aqueous solutions

International Nuclear Information System (INIS)

Kumbhar, A.G.; Kishore, Kamal

2003-01-01

A number of amines can be employed for all volatile treatment (AVT) of steam generator (SG) systems of nuclear power reactors. These amines form complexes with Cu 2+ and Ni 2+ ions which come into water due to corrosion. The redox reactions of a number of Cu(II)-AVT amine complexes and the stability of the transient species formed have been studied by pulse radiolysis technique. Rate constants for the reaction of e aq - with a number of Cu(II)-amine complexes have been determined by following the decay of e aq - absorption. Stability of Cu(I)-amine complexes was studied by following the kinetics of the bleaching signal formed at the λ max of the Cu(II) amine complex. Except for Cu(I)-triethanolamine complex all other Cu(I)-amine complexes were found to be stable. One-electron oxidation of Cu(II) amine complexes was studied using azidyl radicals for the oxidation reaction as OH radicals react with the alcohol groups present in the amines used in this study. Cu(III)-amine complexes were found to be unstable and decayed by second-order kinetics

Generation of induced pluripotent stem cells (iPSCs) stably expressing CRISPR-based synergistic activation mediator (SAM).

Science.gov (United States)

Xiong, Kai; Zhou, Yan; Hyttel, Poul; Bolund, Lars; Freude, Kristine Karla; Luo, Yonglun

2016-11-01

Human fibroblasts were engineered to express the CRISPR-based synergistic activation mediator (SAM) complex: dCas9-VP64 and MS2-P65-HSF1. Two induced pluripotent stem cells (iPSCs) clones expressing SAM were established by transducing these fibroblasts with lentivirus expressing OCT4, SOX2, KLF4 and C-MYC. We have validated that the reprogramming cassette is silenced in the SAM iPSC clones. Expression of pluripotency genes (OCT4, SOX2, LIN28A, NANOG, GDF3, SSEA4, and TRA-1-60), differentiation potential to all three germ layers, and normal karyotypes are validated. These SAM-iPSCs provide a novel, useful tool to investigate genetic regulation of stem cell proliferation and differentiation through CRISPR-mediated activation of endogenous genes. Copyright © 2016 Michael Boutros, German Cancer Research Center, Heidelberg, Germany. Published by Elsevier B.V. All rights reserved.

Produksi Bahasa Tertulis Mahasiswa Penderita Disgrafia Di Fakultas Ilmu Budaya Universitas Sam Ratulangi

OpenAIRE

TANGKE, RIMA APRILIANA

2015-01-01

This research is entitled “Written Language Production of Student with Disgraphia in Faculty of Humanity Sam Ratulangi University”. The objectives of this research are to describe dysgraphia itself and to analyze the influences of dysgraphia on the written language production of the student in Faculty of Humanity, Sam Ratulangi University. This research uses a descriptive method. There are three steps to finish this research, the first step is preparation. In this step, the writer reads the r...

Controlling formation of single-molecule junctions by electrochemical reduction of diazonium terminal groups.

Science.gov (United States)

Hines, Thomas; Díez-Pérez, Ismael; Nakamura, Hisao; Shimazaki, Tomomi; Asai, Yoshihiro; Tao, Nongjian

2013-03-06

We report controlling the formation of single-molecule junctions by means of electrochemically reducing two axialdiazonium terminal groups on a molecule, thereby producing direct Au-C covalent bonds in situ between the molecule and gold electrodes. We report a yield enhancement in molecular junction formation as the electrochemical potential of both junction electrodes approach the reduction potential of the diazonium terminal groups. Step length analysis shows that the molecular junction is significantly more stable, and can be pulled over a longer distance than a comparable junction created with amine anchoring bonds. The stability of the junction is explained by the calculated lower binding energy associated with the direct Au-C bond compared with the Au-N bond.

Poly(amido amine) dendrimers as absorption enhancers for oral delivery of camptothecin.

Science.gov (United States)

Sadekar, S; Thiagarajan, G; Bartlett, K; Hubbard, D; Ray, A; McGill, L D; Ghandehari, H

2013-11-01

Oral delivery of camptothecin has a treatment advantage but is limited by low bioavailability and gastrointestinal toxicity. Poly(amido amine) or PAMAM dendrimers have shown promise as intestinal penetration enhancers, drug solubilizers and drug carriers for oral delivery in vitro and in situ. There have been very limited studies in vivo to evaluate PAMAM dendrimers for oral drug delivery. In this study, camptothecin (5 mg/kg) was formulated and co-delivered with cationic, amine-terminated PAMAM dendrimer generation 4.0 (G4.0) (100 and 300 mg/kg) and anionic, carboxylate-terminated PAMAM generation 3.5 (G3.5) (300 and 1000 mg/kg) in CD-1 mice. Camptothecin associated to a higher extent with G4.0 than G3.5 in the formulation, attributed to an electrostatic interaction on the surface of G4.0. Both PAMAM G4.0 and G3.5 increased camptothecin solubilization in simulated gastric fluid and caused a 2-3 fold increase in oral absorption of camptothecin when delivered at 2 h. PAMAM G4.0 and G3.5 did not increase mannitol transport suggesting that the oral absorption of camptothecin was not due to tight junction modulation. Histologic observations of the epithelial layer of small intestinal segments of the gastrointestinal tract (GIT) at 4 h post dosing supported no evidence of toxicity at the evaluated doses of PAMAM dendrimers. This study demonstrates that both cationic (G.4) and anionic (G3.5) PAMAM dendrimers were effective in enhancing the oral absorption of camptothecin. Results suggest that drug inclusion in PAMAM interior controlled solubilization in simulated gastric and intestinal fluids, and increased oral bioavailability. Copyright © 2013 Elsevier B.V. All rights reserved.

THE MYTH OF MATERIAL SUCCESS AS REFLECTED IN SAM WALTON: MADE IN AMERICA-MY STORY

Directory of Open Access Journals (Sweden)

Utut Kurniati

2015-12-01

Full Text Available American myth of material success had been orchestrated five basic beliefs that were reflected in Sam Walton’s biography, Sam Walton: Made in America-My Story. Those beliefs were: 1 Having a strong will to be successful man in America, Sam Walton was aware that the American democracy allowed its citizens to rise above any limitation in which they may have been born; 2 Then, he rose up from his limitation by hard work. His hard work successfully brought him to the riches and physical comforts; 3 He believed that those rewards came to those who were deserving of them (virtuous; 4 He also believed that those rewards came to those who had the drive and ambition to attain them. Therefore, he was optimistic to attain success in America; 5 Hard work to attain success made Sam Walton a lucky man who received good luck in his life. As a result, his dream of being a successful man in America came true. Keywords: the myth of material success, American dream, hard work

Analysis of the in-vessel phase of SAM strategy for a Korean 1000 MWe PWR

Energy Technology Data Exchange (ETDEWEB)

Cho, Sung-Min; Oh, Seung-Jong [KEPCO International Nuclear Graduate School (KINGS), Ulsan (Korea, Republic of). Dept. of NPP Engineering; Diab, Aya [KEPCO International Nuclear Graduate School (KINGS), Ulsan (Korea, Republic of). Dept. of NPP Engineering; Ain Shams Univ., Cairo (Egypt). Mechanical Power Engineering Dept.

2017-12-15

This paper focuses on the in-vessel phase of Severe Accident Management (SAM) strategy for a Korean 1000 MWe Pressurized Water Reactor (PWR) with reference to ROAAM+ framework approach. To apply ROAAM+, it is needed to identify epistemic and aleatory uncertainties. The selected scenario is a station blackout (SBO) and the corresponding SAM strategy is RCS depressurization followed by water injection into the reactor pressure vessel (RPV). The analysis considers the depressurization timing and the flow rate and timing of in-vessel injection for scenario variations. For the phenomenological uncertainties, the core melting and relocation process is considered to be the most important phenomenon in the in-vessel phase of SAM strategy. Accordingly, a sensitivity analysis is carried out to assess the impact of the cut-off porosity below which the flow area of a core node is zero (EPSCUT), and the critical temperature for cladding rupture (TCLMAX) on the core melting and relocation process. In this paper, the SAM strategy for maintaining the integrity of RPV is derived after quantification of the scenario and phenomenological uncertainties.

Nuclear Protein Sam68 Interacts with the Enterovirus 71 Internal Ribosome Entry Site and Positively Regulates Viral Protein Translation.

Science.gov (United States)

Zhang, Hua; Song, Lei; Cong, Haolong; Tien, Po

2015-10-01

Enterovirus 71 (EV71) recruits various cellular factors to assist in the replication and translation of its genome. Identification of the host factors involved in the EV71 life cycle not only will enable a better understanding of the infection mechanism but also has the potential to be of use in the development of antiviral therapeutics. In this study, we demonstrated that the cellular factor 68-kDa Src-associated protein in mitosis (Sam68) acts as an internal ribosome entry site (IRES) trans-acting factor (ITAF) that binds specifically to the EV71 5' untranslated region (5'UTR). Interaction sites in both the viral IRES (stem-loops IV and V) and the heterogeneous nuclear ribonucleoprotein K homology (KH) domain of Sam68 protein were further mapped using an electrophoretic mobility shift assay (EMSA) and biotin RNA pulldown assay. More importantly, dual-luciferase (firefly) reporter analysis suggested that overexpression of Sam68 positively regulated IRES-dependent translation of virus proteins. In contrast, both IRES activity and viral protein translation significantly decreased in Sam68 knockdown cells compared with the negative-control cells treated with short hairpin RNA (shRNA). However, downregulation of Sam68 did not have a significant inhibitory effect on the accumulation of the EV71 genome. Moreover, Sam68 was redistributed from the nucleus to the cytoplasm and interacts with cellular factors, such as poly(rC)-binding protein 2 (PCBP2) and poly(A)-binding protein (PABP), during EV71 infection. The cytoplasmic relocalization of Sam68 in EV71-infected cells may be involved in the enhancement of EV71 IRES-mediated translation. Since Sam68 is known to be a RNA-binding protein, these results provide direct evidence that Sam68 is a novel ITAF that interacts with EV71 IRES and positively regulates viral protein translation. The nuclear protein Sam68 is found as an additional new host factor that interacts with the EV71 IRES during infection and could potentially

Reductive amination with zinc powder in aqueous media

Directory of Open Access Journals (Sweden)

Giovanni B. Giovenzana

2011-08-01

Full Text Available Zinc powder in aqueous alkaline media was employed to perform reductive amination of aldehydes with primary amines. The corresponding secondary amines were obtained in good yields along with minor amounts of hydrodimerization byproducts. The protocol is a green alternative to the use of complex hydrides in chlorinated or highly flammable solvents.

Thermometric titrations of amines with nitrosyl perchlorate in acetonitrile solvent.

Science.gov (United States)

Gündüz, T; Kiliç, E; Cakirer, O

1996-05-01

Thirteen aliphatic and four aromatic amines, namely diethylamine, triethylamine, n-propylamine, di-n-propylamine, tri-n-butylamine, isopropylamine, di-isopropylamine, n-butylamine, di-n-butylamine, tri-n-butylamine, isobutylamine, sec-butylamine, tert-butylamine, aniline, N,N-dimethylaniline, 2-nitroaniline and 4-nitroaniline were titrated thermometrically with nitrosyl perchlorate in acetonitrile solvent. All the aliphatic amines gave very well-shaped thermometric titration curves. The calculated recovery values of the amines were very good. In comparison, the aromatic amines, aniline and N,N-dimethylaniline gave rather well-shaped titration curves, but the recovery values were fairly low. 2-Nitro- and 4-nitro anilines gave no thermometric response at all. The heats of reaction of the amines with nitrosyl perchlorate are rather high. However, the average heat of reaction of the aromatic amines is approximately two-thirds that of the average heat of the aliphatic amines. To support this method all the amines were also titrated potentiometrically and very similar results to those obtained with the thermometric method are seen. The nitrosyl ion is a Lewis acid, strong enough to titrate quantitatively aliphatic amines in acetonitrile solvent, but not strong enough to titrate aromatic amines at the required level in the same solvent.

77 FR 67813 - Sam Rayburn Dam Project Power Rate

Science.gov (United States)

2012-11-14

... DEPARTMENT OF ENERGY Southwestern Power Administration Sam Rayburn Dam Project Power Rate AGENCY: Southwestern Power Administration, DOE. ACTION: Notice of Rate Order Approving an Extension of Power Rate on an.... James K. McDonald, Assistant Administrator, Southwestern Power Administration, Department of Energy...

SAM : an experiment dedicated to the Carbon Quest at Mars

Science.gov (United States)

Coll, Patrice; Mahaffy, Paul; Webster, Chris; Cabane, Michel; Tan, F.; Coscia, D.; Nolan, T.; Rahen, E.; Teinturier, S.; Goutail, J. P.; Martin, D.; Montaron, C.; Galic, A.

SAM is a suite of instruments that will be onboard the Mars Science Laboratory (MSL) rover. The SAM team consist of scientists and engineers at GSFC, U. Paris/CNRS, JPL, and Honeybee Robotics, along with many additional external partners. SAM's five science goals will address three of the most fundamental questions about the ability of Mars to support life -past, present, and future. Question 1: What does the inventory of carbon compounds near the surface of Mars tell us about its potential habitability? 1.Goal 1: Survey carbon compound sources and evaluate their possible mechanism of formation and destruction. 2.Goal 2: Search for organic compounds of biotic and prebiotic importance expecially methane. Question 2: What are the chemical and isotopic states of the lighter elements in the solids and atmosphere of Mars and what do they tell us about its potential habitability? 1.Goal 3: Reveal the chemical and isotopic state of elements (i.e., N, H, O, S and others) that are important for life as we know it. 2.Goal 4: Evaluate the habitability of Mars by studying its atmospheric chemistry and the composition of trace species that are evidence of interactions between the atmosphere and soil. Question 3: Were past habitability conditions different from today's? 1.Goal 5: Understand atmospheric and climatic evolution through measurements of noble gas and light element isotopes.

The History of the Austin College Building and Old Main at Sam Houston State University

Science.gov (United States)

Singer, Erin; Shields, Samantha

2017-01-01

Austin Hall and Old Main serve as the heart of what is now Sam Houston State University. The buildings' rich histories help one to understand how Sam Houston State University and its proud teacher education heritage came to be. To begin with Austin Hall's story, the University's original building has a unique and interesting tale that journeys…

Introducing ionic and/or hydrogen bonds into the SAM//Ga2O3 top-interface of Ag(TS)/S(CH2)nT//Ga2O3/EGaIn junctions.

Science.gov (United States)

Bowers, Carleen M; Liao, Kung-Ching; Yoon, Hyo Jae; Rappoport, Dmitrij; Baghbanzadeh, Mostafa; Simeone, Felice C; Whitesides, George M

2014-06-11

Junctions with the structure Ag(TS)/S(CH2)nT//Ga2O3/EGaIn (where S(CH2)nT is a self-assembled monolayer, SAM, of n-alkanethiolate bearing a terminal functional group T) make it possible to examine the response of rates of charge transport by tunneling to changes in the strength of the interaction between T and Ga2O3. Introducing a series of Lewis acidic/basic functional groups (T = -OH, -SH, -CO2H, -CONH2, and -PO3H) at the terminus of the SAM gave values for the tunneling current density, J(V) in A/cm(2), that were indistinguishable (i.e., differed by less than a factor of 3) from the values observed with n-alkanethiolates of equivalent length. The insensitivity of the rate of tunneling to changes in the terminal functional group implies that replacing weak van der Waals contact interactions with stronger hydrogen- or ionic bonds at the T//Ga2O3 interface does not change the shape (i.e., the height or width) of the tunneling barrier enough to affect rates of charge transport. A comparison of the injection current, J0, for T = -CO2H, and T = -CH2CH3--two groups having similar extended lengths (in Å, or in numbers of non-hydrogen atoms)--suggests that both groups make indistinguishable contributions to the height of the tunneling barrier.

Supplementary Material for: A new mode of SAM domain mediated oligomerization observed in the CASKIN2 neuronal scaffolding protein

KAUST Repository

Smirnova, Ekaterina; Kwan, Jamie; Siu, Ryan; Gao, Xin; Zoidl, Georg; Demeler, Borries; Saridakis, Vivian; Donaldson, Logan

2016-01-01

Abstract Background CASKIN2 is a homolog of CASKIN1, a scaffolding protein that participates in a signaling network with CASK (calcium/calmodulin-dependent serine kinase). Despite a high level of homology between CASKIN2 and CASKIN1, CASKIN2 cannot bind CASK due to the absence of a CASK Interaction Domain and consequently, may have evolved undiscovered structural and functional distinctions. Results We demonstrate that the crystal structure of the Sterile Alpha Motif (SAM) domain tandem (SAM1-SAM2) oligomer from CASKIN2 is different than CASKIN1, with the minimal repeating unit being a dimer, rather than a monomer. Analytical ultracentrifugation sedimentation velocity methods revealed differences in monomer/dimer equilibria across a range of concentrations and ionic strengths for the wild type CASKIN2 SAM tandem and a structure-directed double mutant that could not oligomerize. Further distinguishing CASKIN2 from CASKIN1, EGFP-tagged SAM tandem proteins expressed in Neuro2a cells produced punctae that were distinct both in shape and size. Conclusions This study illustrates a new way in which neuronal SAM domains can assemble into large macromolecular assemblies that might concentrate and amplify synaptic responses.

Trace Amines and the Trace Amine-Associated Receptor 1: Pharmacology, Neurochemistry and Clinical Implications

Directory of Open Access Journals (Sweden)

Yue ePei

2016-04-01

Full Text Available Biogenic amines are a collection of endogenous molecules that play pivotal roles as neurotransmitters and hormones. In addition to the classical biogenic amines resulting from decarboxylation of aromatic acids, including dopamine (DA, norepinephrine, epinephrine, serotonin (5-HT and histamine, other biogenic amines, present at much lower concentrations in the central nervous system (CNS, and hence referred to as trace amines (TAs, are now recognized to play significant neurophysiological and behavioural functions. At the turn of the century, the discovery of the trace amine-associated receptor 1 (TAAR1, a phylogenetically conserved G protein-coupled receptor that is responsive to both TAs, such as β-phenylethylamine, octopamine and tyramine, and structurally-related amphetamines, unveiled mechanisms of action for TAs other than interference with aminergic pathways, laying the foundations for deciphering the functional significance of TAs and its mammalian CNS receptor, TAAR1. Although its molecular interactions and downstream targets have not been fully elucidated, TAAR1 activation triggers accumulation of intracellular cAMP, modulates PKA and PKC signalling and interferes with the β-arrestin2-dependent pathway via G protein-independent mechanisms. TAAR1 is uniquely positioned to exert direct control over DA and 5-HT neuronal firing and release, which has profound implications for understanding the pathophysiology of, and therefore designing more efficacious therapeutic interventions for, a range of neuropsychiatric disorders that involve aminergic dysregulation, including Parkinson’s disease, schizophrenia, mood disorders and addiction. Indeed, the recent development of novel pharmacological tools targeting TAAR1 has uncovered the remarkable potential of TAAR1-based medications as new generation pharmacotherapies in neuropsychiatry. This review summarizes recent developments in the study of TAs and TAAR1, their intricate neurochemistry and

Tunable, chemoselective amination via silver catalysis.

Science.gov (United States)

Rigoli, Jared W; Weatherly, Cale D; Alderson, Juliet M; Vo, Brian T; Schomaker, Jennifer M

2013-11-20

Organic N-containing compounds, including amines, are essential components of many biologically and pharmaceutically important molecules. One strategy for introducing nitrogen into substrates with multiple reactive bonds is to insert a monovalent N fragment (nitrene or nitrenoid) into a C-H bond or add it directly to a C═C bond. However, it has been challenging to develop well-defined catalysts capable of promoting predictable and chemoselective aminations solely through reagent control. Herein, we report remarkable chemoselective aminations that employ a single metal (Ag) and a single ligand (phenanthroline) to promote either aziridination or C-H insertion by manipulating the coordination geometry of the active catalysts.

A pilot study investigating the feasibility of symptom assessment manager (SAM), a Web-based real-time tool for monitoring challenging behaviors.

Science.gov (United States)

Loi, Samantha M; Wanasinghage, Sangeeth; Goh, Anita; Lautenschlager, Nicola T; Darby, David G; Velakoulis, Dennis

2018-04-01

Improving and minimizing challenging behaviors seen in psychiatric conditions, including behavioral and psychological symptoms of dementia are important in the care of people with these conditions. Yet there is a lack of systematic evaluation of these as a part of routine clinical care. The Neuropsychiatric Inventory is a validated and reliable tool for rating the severity and disruptiveness of challenging behaviors. We report on the evaluation of a Web-based symptom assessment manager (SAM), designed to address the limitation of previous tools using some of the Neuropsychiatric Inventory functions, to monitor behaviors by staff caring for people with dementia and other psychiatric conditions in inpatient and residential care settings. The SAM was piloted in an 8-bed inpatient neuropsychiatry unit over 5 months. Eleven nurses and 4 clinicians were trained in usage of SAM. Primary outcomes were usage of SAM and perceived usability, utility, and acceptance of SAM. Secondary outcomes were the frequencies of documented behavior. Usage data were analyzed using chi-square and logistic regression analyses. The SAM was used for all admitted patients regardless of diagnosis, with a usage rate of 64% for nurses regularly employed in the unit. Staff provided positive feedback regarding the utility of SAM. The SAM appeared to offer individualized behavior assessment by providing a quick, structured, and standardized platform for assessing behavior in a real-world setting. Further research would involve trialing SAM with more staff in alternative settings such as in home or residential care settings. Copyright © 2017 John Wiley & Sons, Ltd.

Curiosity's Sample Analysis at Mars (SAM) Investigation: Overview of Results from the First 120 Sols on Mars

Science.gov (United States)

Mahaffy, P. R.; Cabane, M.; Webster, C. R.; Archer, P. D.; Atreya, S. K.; Benna, M.; Brinckerhoff, W. B.; Brunner, A. E.; Buch, A.; Coll, P.;

Oxidations of N-(3-indoleethyl) cyclic aliphatic amines by horseradish peroxidase: the indole ring binds to the enzyme and mediates electron-transfer amine oxidation.

Science.gov (United States)

Ling, Ke-Qing; Li, Wen-Shan; Sayre, Lawrence M

2008-01-23

Although oxidations of aromatic amines by horseradish peroxidase (HRP) are well-known, typical aliphatic amines are not substrates of HRP. In this study, the reactions of N-benzyl and N-methyl cyclic amines with HRP were found to be slow, but reactions of N-(3-indoleethyl) cyclic amines were 2-3 orders of magnitude faster. Analyses of pH-rate profiles revealed a dominant contribution to reaction by the amine-free base forms, the only species found to bind to the enzyme. A metabolic study on a family of congeneric N-(3-indoleethyl) cyclic amines indicated competition between amine and indole oxidation pathways. Amine oxidation dominated for the seven- and eight-membered azacycles, where ring size supports the change in hybridization from sp3 to sp2 that occurs upon one-electron amine nitrogen oxidation, whereas only indole oxidation was observed for the six-membered ring congener. Optical difference spectroscopic binding data and computational docking simulations suggest that all the arylalkylamine substrates bind to the enzyme through their aromatic termini with similar binding modes and binding affinities. Kinetic saturation was observed for a particularly soluble substrate, consistent with an obligatory role of an enzyme-substrate complexation preceding electron transfer. The significant rate enhancements seen for the indoleethylamine substrates suggest the ability of the bound indole ring to mediate what amounts to medium long-range electron-transfer oxidation of the tertiary amine center by the HRP oxidants. This is the first systematic investigation to document aliphatic amine oxidation by HRP at rates consistent with normal metabolic turnover, and the demonstration that this is facilitated by an auxiliary electron-rich aromatic ring.

Parabolic Trough Collector Cost Update for the System Advisor Model (SAM)

Energy Technology Data Exchange (ETDEWEB)

Kurup, Parthiv [National Renewable Energy Lab. (NREL), Golden, CO (United States); Turchi, Craig S. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2015-11-01

This report updates the baseline cost for parabolic trough solar fields in the United States within NREL's System Advisor Model (SAM). SAM, available at no cost at https://sam.nrel.gov/, is a performance and financial model designed to facilitate decision making for people involved in the renewable energy industry. SAM is the primary tool used by NREL and the U.S. Department of Energy (DOE) for estimating the performance and cost of concentrating solar power (CSP) technologies and projects. The study performed a bottom-up build and cost estimate for two state-of-the-art parabolic trough designs -- the SkyTrough and the Ultimate Trough. The SkyTrough analysis estimated the potential installed cost for a solar field of 1500 SCAs as $170/m² +/- $6/m². The investigation found that SkyTrough installed costs were sensitive to factors such as raw aluminum alloy cost and production volume. For example, in the case of the SkyTrough, the installed cost would rise to nearly $210/m² if the aluminum alloy cost was $1.70/lb instead of $1.03/lb. Accordingly, one must be aware of fluctuations in the relevant commodities markets to track system cost over time. The estimated installed cost for the Ultimate Trough was only slightly higher at $178/m², which includes an assembly facility of $11.6 million amortized over the required production volume. Considering the size and overall cost of a 700 SCA Ultimate Trough solar field, two parallel production lines in a fully covered assembly facility, each with the specific torque box, module and mirror jigs, would be justified for a full CSP plant.

Membrane topology of Golgi-localized probable S-adenosylmethionine-dependent methyltransferase in tobacco (Nicotiana tabacum) BY-2 cells.

Science.gov (United States)

Liu, Jianping; Hayashi, Kyoko; Matsuoka, Ken

2015-01-01

S-adenosylmethionine (SAM)-dependent methyltransferases (MTases) transfer methyl groups to substrates. In this study, a novel putative tobacco SAM-MTase termed Golgi-localized methyl transferase 1 (GLMT1) has been characterized. GLMT1 is comprised of 611 amino acids with short N-terminal region, putative transmembrane region, and C-terminal SAM-MTase domain. Expression of monomeric red fluorescence protein (mRFP)-tagged protein in tobacco BY-2 cell indicated that GLMT1 is a Golgi-localized protein. Analysis of the membrane topology by protease digestion suggested that both C-terminal catalytic region and N-terminal region seem to be located to the cytosolic side of the Golgi apparatus. Therefore, GLMT1 might have a different function than the previously studied SAM-MTases in plants.

Time-resolved energy transfer from single chloride-terminated nanocrystals to graphene

International Nuclear Information System (INIS)

Ajayi, O. A.; Wong, C. W.; Anderson, N. C.; Wolcott, A.; Owen, J. S.; Cotlet, M.; Petrone, N.; Hone, J.; Gu, T.; Gesuele, F.

2014-01-01

We examine the time-resolved resonance energy transfer of excitons from single n-butyl amine-bound, chloride-terminated nanocrystals to two-dimensional graphene through time-correlated single photon counting. The radiative biexponential lifetime kinetics and blinking statistics of the individual surface-modified nanocrystal elucidate the non-radiative decay channels. Blinking modification as well as a 4× reduction in spontaneous emission were observed with the short chloride and n-butylamine ligands, probing the energy transfer pathways for the development of graphene-nanocrystal nanophotonic devices

Time-resolved energy transfer from single chloride-terminated nanocrystals to graphene

Energy Technology Data Exchange (ETDEWEB)

Ajayi, O. A., E-mail: oaa2114@columbia.edu, E-mail: cww2104@columbia.edu; Wong, C. W., E-mail: oaa2114@columbia.edu, E-mail: cww2104@columbia.edu [Optical Nanostructures Laboratory, Center for Integrated Science and Engineering, Solid-State Science and Engineering, Columbia University, New York, New York 10027 (United States); Department of Mechanical Engineering, Columbia University, New York, New York 10027 (United States); Anderson, N. C.; Wolcott, A.; Owen, J. S. [Department of Chemistry, Columbia University, New York, New York 10027 (United States); Cotlet, M. [Brookhaven National Laboratory, Upton, New York, New York 11973 (United States); Petrone, N.; Hone, J. [Department of Mechanical Engineering, Columbia University, New York, New York 10027 (United States); Gu, T.; Gesuele, F. [Optical Nanostructures Laboratory, Center for Integrated Science and Engineering, Solid-State Science and Engineering, Columbia University, New York, New York 10027 (United States)

2014-04-28

We examine the time-resolved resonance energy transfer of excitons from single n-butyl amine-bound, chloride-terminated nanocrystals to two-dimensional graphene through time-correlated single photon counting. The radiative biexponential lifetime kinetics and blinking statistics of the individual surface-modified nanocrystal elucidate the non-radiative decay channels. Blinking modification as well as a 4× reduction in spontaneous emission were observed with the short chloride and n-butylamine ligands, probing the energy transfer pathways for the development of graphene-nanocrystal nanophotonic devices.

Geometry modeling for SAM-CE Monte Carlo calculations

International Nuclear Information System (INIS)

Steinberg, H.A.; Troubetzkoy, E.S.

1980-01-01

Three geometry packages have been developed and incorporated into SAM-CE, for representing in three dimensions the transport medium. These are combinatorial geometry - a general (non-lattice) system, complex combinatorial geometry - a very general system with lattice capability, and special reactor geometry - a special purpose system for light water reactor geometries. Their different attributes are described

Toposelective electrochemical desorption of thiol SAMs from neighboring polycrystalline gold surfaces.

Science.gov (United States)

Tencer, Michal; Berini, Pierre

2008-11-04

We describe a method for the selective desorption of thiol self-assembled monolayers from gold surfaces having micrometer-scale separations on a substrate. In an electrolyte solution, the electrical resistance between the adjacent areas can be much lower than the resistance between a surface and the counter electrode. Also, both reductive and oxidative thiol desorption may occur. Therefore, the potentials of the surfaces must be independently controlled with a multichannel potentiostat and operating windows for a given thiol/electrolyte system must be established. In this study operating windows were established for 1-dodecanethiol-based SAMs in phosphate buffer, phosphate-buffered saline, and sodium hydroxide solution, and selective SAM removal was successfully performed in a four-electrode configuration.

Metabolomic Changes in Serum of Children with Different Clinical Diagnoses of Malnutrition123

Science.gov (United States)

Di Giovanni, Valeria; Wang, Dominic X; Seshadri, Swapna; Senga, Edward; Versloot, Christian J; Semba, Richard D; Moaddel, Ruin; Ordiz, M Isabel; Zhang, Ling; Parkinson, John; Manary, Mark J; Bandsma, Robert HJ

2016-01-01

Background: Mortality in children with severe acute malnutrition (SAM) remains high despite standardized rehabilitation protocols. Two forms of SAM are classically distinguished: kwashiorkor and marasmus. Children with kwashiorkor have nutritional edema and metabolic disturbances, including hypoalbuminemia and hepatic steatosis, whereas marasmus is characterized by severe wasting. The metabolic changes underlying these phenotypes have been poorly characterized, and whether homeostasis is achieved during hospital stay is unclear. Objectives: We aimed to characterize metabolic differences between children with marasmus and kwashiorkor at hospital admission and after clinical stabilization and to compare them with stunted and nonstunted community controls. Methods: We studied children aged 9–59 mo from Malawi who were hospitalized with SAM (n = 40; 21 with kwashiorkor and 19 with marasmus) or living in the community (n = 157; 78 stunted and 79 nonstunted). Serum from patients with SAM was obtained at hospital admission and 3 d after nutritional stabilization and from community controls. With the use of targeted metabolomics, 141 metabolites, including amino acids, biogenic amines, acylcarnitines, sphingomyelins, and phosphatidylcholines, were measured. Results: At admission, most metabolites (128 of 141; 91%) were lower in children with kwashiorkor than in those with marasmus, with significant differences in several amino acids and biogenic amines, including those of the kynurenine-tryptophan pathway. Several phosphatidylcholines and some acylcarnitines also differed. Patients with SAM had profiles that were profoundly different from those of stunted and nonstunted controls, even after clinical stabilization. Amino acids and biogenic amines generally improved with nutritional rehabilitation, but most sphingomyelins and phosphatidylcholines did not. Conclusions: Children with kwashiorkor were metabolically distinct from those with marasmus, and were more prone to

Metabolomic Changes in Serum of Children with Different Clinical Diagnoses of Malnutrition.

Science.gov (United States)

Di Giovanni, Valeria; Bourdon, Celine; Wang, Dominic X; Seshadri, Swapna; Senga, Edward; Versloot, Christian J; Voskuijl, Wieger; Semba, Richard D; Trehan, Indi; Moaddel, Ruin; Ordiz, M Isabel; Zhang, Ling; Parkinson, John; Manary, Mark J; Bandsma, Robert Hj

2016-12-01

Mortality in children with severe acute malnutrition (SAM) remains high despite standardized rehabilitation protocols. Two forms of SAM are classically distinguished: kwashiorkor and marasmus. Children with kwashiorkor have nutritional edema and metabolic disturbances, including hypoalbuminemia and hepatic steatosis, whereas marasmus is characterized by severe wasting. The metabolic changes underlying these phenotypes have been poorly characterized, and whether homeostasis is achieved during hospital stay is unclear. We aimed to characterize metabolic differences between children with marasmus and kwashiorkor at hospital admission and after clinical stabilization and to compare them with stunted and nonstunted community controls. We studied children aged 9-59 mo from Malawi who were hospitalized with SAM (n = 40; 21 with kwashiorkor and 19 with marasmus) or living in the community (n = 157; 78 stunted and 79 nonstunted). Serum from patients with SAM was obtained at hospital admission and 3 d after nutritional stabilization and from community controls. With the use of targeted metabolomics, 141 metabolites, including amino acids, biogenic amines, acylcarnitines, sphingomyelins, and phosphatidylcholines, were measured. At admission, most metabolites (128 of 141; 91%) were lower in children with kwashiorkor than in those with marasmus, with significant differences in several amino acids and biogenic amines, including those of the kynurenine-tryptophan pathway. Several phosphatidylcholines and some acylcarnitines also differed. Patients with SAM had profiles that were profoundly different from those of stunted and nonstunted controls, even after clinical stabilization. Amino acids and biogenic amines generally improved with nutritional rehabilitation, but most sphingomyelins and phosphatidylcholines did not. Children with kwashiorkor were metabolically distinct from those with marasmus, and were more prone to severe metabolic disruptions. Children with SAM showed

Development of I-123-labeled amines for brain studies: localization of I-123 iodophenylalkyl amines in rat brain

International Nuclear Information System (INIS)

Winchell, H.S.; Baldwin, R.M.; Lin, T.H.

1980-01-01

Localization in rat brain of forty iodophenylalkyl amines labeled with I-123 was evaluated in an attempt to develop I-123-labeled amines useful for brain studies. For the amines studied, the highest activity in brain and the brain-to-blood activity ratios ranked p > m > o as related to iodine position on the benzene ring: for alkyl groups the rank order was α-methylethyl > ethyl > methyl > none; for N additions it was single lipophilic group > H > two lipophilic groups. It is suggested that introduction of a halogen into the ring structure of many amines results in greater concentration of the agent in brain than is seen with the nonhalogenated parent compound. The agent N-isopropyl-p-iodoamphetamine was chosen for further study because, in the rat, it showed high brain activity (1.57%/g) and brain-blood ratio (12.6) at 5 min

New insights into controlling tube-bundle fouling using alternative amines

Energy Technology Data Exchange (ETDEWEB)

Turner, C.W.; Klimas, S.J.; Guzonas, D.A.; Fruzzetti, K. [Atomic Energy of Canada Ltd. (Canada); Frattini, P.L. [Electric Power Research Inst. (United States)

2002-07-01

A volatile amine is added to the secondary heat-transport system of a nuclear power plant to reduce the rate of corrosion and corrosion product transport in the feedwater and to protect steam generator (SG) crevices and materials exposed to steam condensate. Volatility and base strength of the amine at the SG operating temperature are two important considerations when choosing the optimum amine (or mixture of amines) for corrosion control in the steam cycle. The investigation has found that the rate of tube-bundle fouling is strongly dependent upon the surface chemistry of the corrosion products. For example, the fouling rates of fully oxidized iron oxides, such as hematite and lepidocrocite, are at least an order of magnitude greater than the fouling rate of magnetite under identical operating conditions. The difference is related to the sign of the surface charge on the corrosion products at temperature. The choice of amine for pH-control also influences the fouling rate. This was originally thought to be a surface-charge effect as well, but recent tests have suggested that it is related to the role that the amine plays in governing the rate of deposit consolidation on the heat-transfer surface. Amines that promote a high rate of deposit consolidation result in a low rate of deposit removal and a high fouling rate. Conversely, amines that tend to inhibit deposit consolidation produce a higher rate of deposit removal and a lower fouling rate. Dimethyl-amine and dodecyl-amine have been identified as two amines that inhibit the rate of deposit consolidation and, consequently, result in fouling rates that are up to 5 times lower than rates measured for amines that promote consolidation. A significant difference between morpholine (high fouling rate) and dimethyl-amine (low fouling rate) is that the latter desorbs more slowly from the surface of magnetite. How to account for a correlation between slow desorption kinetics and lower rate constants for deposition and

New insights into controlling tube-bundle fouling using alternative amines

International Nuclear Information System (INIS)

Turner, C.W.; Klimas, S.J.; Guzonas, D.A.; Fruzzetti, K.; Frattini, P.L.

2002-01-01

A volatile amine is added to the secondary heat-transport system of a nuclear power plant to reduce the rate of corrosion and corrosion product transport in the feedwater and to protect steam generator (SG) crevices and materials exposed to steam condensate. Volatility and base strength of the amine at the SG operating temperature are two important considerations when choosing the optimum amine (or mixture of amines) for corrosion control in the steam cycle. The investigation has found that the rate of tube-bundle fouling is strongly dependent upon the surface chemistry of the corrosion products. For example, the fouling rates of fully oxidized iron oxides, such as hematite and lepidocrocite, are at least an order of magnitude greater than the fouling rate of magnetite under identical operating conditions. The difference is related to the sign of the surface charge on the corrosion products at temperature. The choice of amine for pH-control also influences the fouling rate. This was originally thought to be a surface-charge effect as well, but recent tests have suggested that it is related to the role that the amine plays in governing the rate of deposit consolidation on the heat-transfer surface. Amines that promote a high rate of deposit consolidation result in a low rate of deposit removal and a high fouling rate. Conversely, amines that tend to inhibit deposit consolidation produce a higher rate of deposit removal and a lower fouling rate. Dimethyl-amine and dodecyl-amine have been identified as two amines that inhibit the rate of deposit consolidation and, consequently, result in fouling rates that are up to 5 times lower than rates measured for amines that promote consolidation. A significant difference between morpholine (high fouling rate) and dimethyl-amine (low fouling rate) is that the latter desorbs more slowly from the surface of magnetite. How to account for a correlation between slow desorption kinetics and lower rate constants for deposition and

ASAMPSA-E guidance for level 2 PSA Volume 3. Verification and improvement of SAM strategies with L2 PSA

International Nuclear Information System (INIS)

Rahni, N.; Raimond, E.; Jan, P.; Lopez, J.; Loeffler, H.; Mildenberger, O.; Kubicek, J.; Vitazkova, J.; Ivanov, I.; Groudev, P.; Lajtha, G.; Serrano, C.; Zhabin, O.; Prosek, Andrej; Dirksen, G.; Yu, S.; Oury, L.; Hultqvist, G.

2016-01-01

For each NPP, severe accident management (SAM) strategies shall make use of components or systems and human resources to limit as far as possible the consequences of any severe accident on-site and off-site. L2 PSA is one of the tools that can be used to verify and improve these strategies. The present report (deliverable D40.5 of the project ASAMPSA-E) provides an opportunity for a comparison of objectives in the different countries in terms of SAM strategies verification and improvement. The report summarizes also experience of each partner (including potential deficiencies) involved in this activity, in order to derive some good practices and required progress, addressing: - SAM modeling in L2 PSA, - Positive and negative aspects in current SAM practices, - Discussion on possible criteria related to L2 PSA for verification and improvement: risk reduction (in relation with WP30 activities on risk metrics), reduction of uncertainties on the severe accident progression paths until NPP stabilization, reduction of human failure conditional probabilities (depending on the SAM strategy, the environmental conditions...), - Review with a perspective of verification and improvement of the main SAM strategies (corium cooling, RCS depressurization, control of flammable gases, reactivity control, containment function, containment pressure control, limitation of radioactive releases,...), - SAM strategies to be considered in the context of an extended L2 PSA (as far possible, depending on existing experience), taking into account all operating modes, accidents also occurring in the SFPs and long term and multi-unit accidents. The deliverable D40.5 is developed from the partners' experience. Many of the topics described here are beyond the common practices of L2 PSA applications: in some countries, L2 PSA application is limited to the calculations of frequencies of release categories with no formal requirement for SAM verification and improvement. (authors)

Annals of SAM meeting '96. National meeting on precious metals

International Nuclear Information System (INIS)

1996-01-01

Works are presented at the SAM meeting '96 of the Argentine Materials Association. The papers can be grouped under the following main topics: physical metallurgy; ceramics; polymers; precious metals; extractive metallurgy; corrosion; powder metallurgy. refs., ills

The multi-state energy landscape of the SAM-I riboswitch: A single-molecule Förster resonance energy transfer spectroscopy study

Science.gov (United States)

Manz, Christoph; Kobitski, Andrei Yu.; Samanta, Ayan; Jäschke, Andres; Nienhaus, G. Ulrich

2018-03-01

RNA (ribonucleic acid) molecules are highly flexible biopolymers fluctuating at physiological temperatures among many different conformations that are represented by minima in a hierarchical conformational free energy landscape. Here we have employed single-molecule FRET (smFRET) to explore the energy landscape of the B. subtilis yitJ SAM-I riboswitch (RS). In this small RNA molecule, specific binding of an S-adenosyl-L-methionine (SAM) ligand in the aptamer domain regulates gene expression by inducing structural changes in another domain, the expression platform, causing transcription termination by the RNA polymerase. We have measured smFRET histograms over wide ranges of Mg2+ concentration for three RS variants that were specifically labeled with fluorescent dyes on different sites. In the analysis, different conformations are associated with discrete Gaussian model distributions, which are typically fairly broad on the FRET efficiency scale and thus can be extremely challenging to unravel due to their mutual overlap. Our earlier work on two SAM-I RS variants revealed four major conformations. By introducing a global fitting procedure which models both the Mg2+ concentration dependencies of the fractional populations and the average FRET efficiencies of the individual FRET distributions according to Mg2+ binding isotherms, we were able to consistently describe the histogram data of both variants at all studied Mg2+ concentrations. With the third FRET-labeled variant, however, we found significant deviations when applying the four-state model to the data. This can arise because the different FRET labeling of the new variant allows two states to be distinguished that were previously not separable due to overlap. Indeed, the resulting five-state model presented here consistently describes the smFRET histograms of all three variants as well as their variations with Mg2+ concentration. We also performed a triangulation of the donor position for two of the constructs

BIOGENIC AMINES CONTENT IN DIFFERENT WINE SAMPLES

Directory of Open Access Journals (Sweden)

Attila Kántor

2015-02-01

Full Text Available Twenty-five samples of different Slovak wines before and after filtration were analysed in order to determine the content of eight biogenic amines (tryptamine, phenylalanine, putrescine, cadaverine, histamine, tyramine, spermidine and spermine. The method involves extraction of biogenic amines from wine samples with used dansyl chloride. Ultra-high performance liquid chromatography (UHPLC was used for determination of biogenic amines equipped with a Rapid Resolution High Definition (RRHD, DAD detectors and Extend-C18 LC column (50 mm x 3.0 mm ID, 1.8 μm particle size. In this study the highest level of biogenic amine in all wine samples represent tryptamine (TRM with the highest content 170.9±5.3 mg/L in Pinot Blanc wine. Phenylalanine (PHE cadaverine (CAD, histamine (HIS and spermidine (SPD were not detected in all wines; mainly SPD was not detected in 16 wines, HIS not detected in 14 wines, PHE and CAD not detected in 2 wines. Tyramine (TYR, spermine (SPN and putrescine (PUT were detected in all wines, but PUT and SPN in very low concentration. The worst wine samples with high biogenic amine content were Saint Laurent (BF, Pinot Blanc (S and Pinot Noir (AF.

Aliphatic semisynthetic amino terminal variants of myoglobin: enrichment with carbon-13, determination and interpretation of terminal pK values and motions

International Nuclear Information System (INIS)

Busch, M.R.

1985-01-01

The synthesis of a series of myoglobins substituted in the amino terminal residue to provide variation in the aliphatic nature of the side chain and enrichment in 13 C was accomplished by semisynthetic methods. The replacements of valine, the native first residue, included 13 C enriched glycine, alanine, valine, leucine, and isoleucine. The products were extensively characterized and found to be virtually indistinguishable by most physical methods. 13 C NMR spectroscopy showed significant differences in the amino terminal pK value, ranging from 7.72 for myoglobin to 7.15 for myoglobin. Consideration of the electrostatic effects of the charge array indicated a balance of interactions at this site not significantly altered by variations in the side chain. By examination of the crystal structure, consideration of earlier work regarding the interactions of the side chain of Leu-2, and data regarding the motions of the terminal residue, it was concluded that the interaction of the side chain of the first residue with the hydrophobic cluster formed primarily by close contact of invariant residues Leu-2 and Leu-137 was the primary cause for the reduction in the terminal pK values seen for the larger aliphatics. By restricting the freedom of the residue, this interaction limits the available hydration volume, and consequently favors the unprotonated form of the amine. The concurrent observation of both functional elements in the series of α amino terminal residues brings out the interrelated consequences for the two categories of solvent interactions controlling structural and functional properties in a graded way

Biogenic amine formation and bacterial contribution in Natto products.

Science.gov (United States)

Kim, Bitna; Byun, Bo Young; Mah, Jae-Hyung

2012-12-01

Twenty-one Natto products currently distributed in Korea were analysed for biogenic amine contents and tested to determine physicochemical and bacterial contributions to biogenic amine formation. Among them, nine products (about 43%) had β-phenylethylamine or tyramine contents greater than the toxic dose (30mg/kg and 100mg/kg, respectively) of each amine, although no products showed total amounts of biogenic amines above the harmful level (1000mg/kg), which indicates that the amounts of biogenic amines in some Natto products are not within the safe level for human health. From four different Natto products, that contained noticeable levels of β-phenylethylamine and tyramine, 80 bacterial strains were isolated. All the strains were identified to be Bacillus subtilis and highly capable of producing β-phenylethylamine and tyramine. Therefore, it seems likely that the remarkable contents of β-phenylethylamine and tyramine in Natto predominantly resulted from the strains highly capable of producing those amines present in the food. Copyright © 2012 Elsevier Ltd. All rights reserved.

Sodium Perborate Oxidation of an Aromatic Amine

Science.gov (United States)

Juestis, Laurence

1977-01-01

Describes an experiment involving the oxidation of aromatic primary amines to the corresponding azo compound; suggests procedures for studying factors that influence the yield of such a reaction, including the choice of solvent and the oxidant-amine ratio. (MLH)

A Catalyst-Free Amination of Functional Organolithium Reagents by Flow Chemistry.

Science.gov (United States)

Kim, Heejin; Yonekura, Yuya; Yoshida, Jun-Ichi

2018-04-03

Reported is the electrophilic amination of functional organolithium intermediates with well-designed aminating reagents under mild reaction conditions using flow microreactors. The aminating reagents were optimized to achieve efficient C-N bond formation without using any catalyst. The electrophilic amination reactions of functionalized aryllithiums were successfully conducted under mild reaction conditions, within 1 minute, by using flow microreactors. The aminating reagent was also prepared by the flow method. Based on stopped-flow NMR analysis, the reaction time for the preparation of the aminating reagent was quickly optimized without the necessity of work-up. Integrated one-flow synthesis consisting of the generation of an aryllithium, the preparation of an aminating reagent, and their combined reaction was successfully achieved to give the desired amine within 5 minutes of total reaction time. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Method for the production of primary amines

NARCIS (Netherlands)

Baldenius, Kai-Uwe; Ditrich, Klaus; Breurer, Michael; Navickas, Vaidotas; Janssen, Dick; Crismaru, Ciprian; Bartsch, Sebastian

2014-01-01

The present invention relates to a novel enzymatically catalyzed method for the production of aliphatic primary amines, which method comprises the enzymatic oxidation of a primary aliphatic alcohol catalyzed by an alcohol dehydrogenase, amination of the resulting oxocompound catalyzed by a

Vibrational Stark Effect of the Electric-Field Reporter 4-Mercaptobenzonitrile as a Tool for Investigating Electrostatics at Electrode/SAM/Solution Interfaces

Directory of Open Access Journals (Sweden)

Peter Hildebrandt

2012-06-01

Full Text Available 4-mercaptobenzonitrile (MBN in self-assembled monolayers (SAMs on Au and Ag electrodes was studied by surface enhanced infrared absorption and Raman spectroscopy, to correlate the nitrile stretching frequency with the local electric field exploiting the vibrational Stark effect (VSE. Using MBN SAMs in different metal/SAM interfaces, we sorted out the main factors controlling the nitrile stretching frequency, which comprise, in addition to external electric fields, the metal-MBN bond, the surface potential, and hydrogen bond interactions. On the basis of the linear relationships between the nitrile stretching and the electrode potential, an electrostatic description of the interfacial potential distribution is presented that allows for determining the electric field strengths on the SAM surface, as well as the effective potential of zero-charge of the SAM-coated metal. Comparing this latter quantity with calculated values derived from literature data, we note a very good agreement for Au/MBN but distinct deviations for Ag/MBN which may reflect either the approximations and simplifications of the model or the uncertainty in reported structural parameters for Ag/MBN. The present electrostatic model consistently explains the electric field strengths for MBN SAMs on Ag and Au as well as for thiophenol and mercaptohexanoic acid SAMs with MBN incorporated as a VSE reporter.

Assessing the suitability of written stroke materials: an evaluation of the interrater reliability of the suitability assessment of materials (SAM) checklist.

Science.gov (United States)

Hoffmann, Tammy; Ladner, Yvette

2012-01-01

Written materials are frequently used to provide education to stroke patients and their carers. However, poor quality materials are a barrier to effective information provision. A quick and reliable method of evaluating material quality is needed. This study evaluated the interrater reliability of the Suitability Assessment of Materials (SAM) checklist in a sample of written stroke education materials. Two independent raters evaluated the materials (n = 25) using the SAM, and ratings were analyzed to reveal total percentage agreements and weighted kappa values for individual items and overall SAM rating. The majority of the individual SAM items had high interrater reliability, with 17 of the 22 items achieving substantial, almost perfect, or perfect weighted kappa value scores. The overall SAM rating achieved a weighted kappa value of 0.60, with a percentage total agreement of 96%. Health care professionals should evaluate the content and design characteristics of written education materials before using them with patients. A tool such as the SAM checklist can be used; however, raters should exercise caution when interpreting results from items with more subjective scoring criteria. Refinements to the scoring criteria for these items are recommended. The value of the SAM is that it can be used to identify specific elements that should be modified before education materials are provided to patients.

Dual C-H functionalization of N-aryl amines: synthesis of polycyclic amines via an oxidative Povarov approach.

Science.gov (United States)

Min, Chang; Sanchawala, Abbas; Seidel, Daniel

2014-05-16

Iminium ions generated in situ via copper(I) bromide catalyzed oxidation of N-aryl amines readily undergo [4 + 2] cycloadditions with a range of dienophiles. This method involves the functionalization of both a C(sp(3))-H and a C(sp(2))-H bond and enables the rapid construction of polycyclic amines under relatively mild conditions.

Direct electrochemical imidation of aliphatic amines via anodic oxidation.

Science.gov (United States)

Zhang, Li; Su, Ji-Hu; Wang, Sujing; Wan, Changfeng; Zha, Zhenggen; Du, Jiangfeng; Wang, Zhiyong

2011-05-21

Direct electrochemical synthesis of sulfonyl amidines from aliphatic amines and sulfonyl azides was realized with good to excellent yields. Traditional tertiary amine substrates were broadened to secondary and primary amines. The reaction intermediates were observed and a reaction mechanism was proposed and discussed. © The Royal Society of Chemistry 2011

Catalytic Ester and Amide to Amine Interconversion: Nickel-Catalyzed Decarbonylative Amination of Esters and Amides by C−O and C−C Bond Activation

KAUST Repository

Yue, Huifeng

2017-03-15

An efficient nickel-catalyzed decarbonylative amination reaction of aryl and heteroaryl esters has been achieved for the first time. The new amination protocol allows the direct interconversion of esters and amides into the corresponding amines and represents a good alternative to classical rearrangements as well as cross coupling reactions.

Transition Metal Free C-N Bond Forming Dearomatizations and Aryl C-H Aminations by in Situ Release of a Hydroxylamine-Based Aminating Agent.

Science.gov (United States)

Farndon, Joshua J; Ma, Xiaofeng; Bower, John F

2017-10-11

We outline a simple protocol that accesses directly unprotected secondary amines by intramolecular C-N bond forming dearomatization or aryl C-H amination. The method is dependent on the generation of a potent electrophilic aminating agent released by in situ deprotection of O-Ts activated N-Boc hydroxylamines.

Catalytic Ester and Amide to Amine Interconversion: Nickel-Catalyzed Decarbonylative Amination of Esters and Amides by C−O and C−C Bond Activation

KAUST Repository

Yue, Huifeng; Guo, Lin; Liao, Hsuan-Hung; Cai, Yunfei; Zhu, Chen; Rueping, Magnus

2017-01-01

An efficient nickel-catalyzed decarbonylative amination reaction of aryl and heteroaryl esters has been achieved for the first time. The new amination protocol allows the direct interconversion of esters and amides into the corresponding amines and represents a good alternative to classical rearrangements as well as cross coupling reactions.

Intolerance to dietary biogenic amines: A review

NARCIS (Netherlands)

Jansen, S.C.; Dusseldorp, M. van; Bottema, K.C.; Dubois, A.E.J.

2003-01-01

Objective: To evaluate the scientific evidence for purported intolerance to dietary biogenic amines. Data Sources: MEDLINE was searched for articles in the English language published between January 1966 and August 2001. The keyword biogenic amin* was combined with hypersens*, allerg*, intoler*, and

Intolerance to dietary biogenic amines : a review

NARCIS (Netherlands)

Jansen, SC; van Dusseldorp, M; Bottema, KC; Dubois, AEJ

Objective: To evaluate the scientific evidence for purported intolerance to dietary biogenic amines. Data Sources: MEDLINE was searched for articles in the English language published between January 1966 and August 2001. The keyword biogenic amin* was combined with hypersens*, allergen intoler*, and

Rhodium deposition onto a 4-mercaptopyridine SAM on Au(1 1 1)

Energy Technology Data Exchange (ETDEWEB)

Manolova, M. [Institute of Electrochemistry, University of Ulm, 89069 Ulm (Germany); Kayser, M. [Institute of Electrochemistry, University of Ulm, 89069 Ulm (Germany); Kolb, D.M. [Institute of Electrochemistry, University of Ulm, 89069 Ulm (Germany)]. E-mail: dieter.kolb@uni-ulm.de; Boyen, H.-G. [Institute of Solid State Physics, University of Ulm, 89069 Ulm (Germany); Ziemann, P. [Institute of Solid State Physics, University of Ulm, 89069 Ulm (Germany); Mayer, D. [BASF Electronic Materials GmbH, 67056 Ludwigshafen (Germany); Wirth, A. [BASF Electronic Materials GmbH, 67056 Ludwigshafen (Germany)

2007-02-10

The application of a recently developed method for the deposition of Pd and Pt on top of a SAM, has been successfully extended to Rh, thus proving the versatility of the new concept. Experimental evidence from cyclic voltammetry, in situ STM and ex situ X-ray photoemission spectroscopy is presented for the deposition of monoatomic high rhodium islands onto a 4-mercaptopyridine self-assembled monolayer on a Au(1 1 1) electrode. By repetitive complexation of the Rh ions to the ring-nitrogen and reduction in a Rh-ion free solution, an almost completely covered SAM is obtained. The consequences of making contacts for molecular electronics are briefly discussed.

Analysis of a Buchwald-Hartwig amination: reaction for pharmaceutical production

DEFF Research Database (Denmark)

Christensen, Henrik

The Buchwald-Hartwig amination reaction is widely used in the production of N-arylated amines in the pharmaceutical industry. The reaction is betweenan aryl halogen and a primary or secondary amine in the presence of a base and a homogeneous catalyst giving the desired N-arylated amine. Due to mild...... is to increase the understanding of the chem­ical reaction mechanisms and kinetics for the Buchwald-Hartwig amination reaction. Also, to develop methods for application of these mechanisms and kinetics to optimize and scale up an organic synthesis to an industrial phar­maceutical production. The Buchwald...

Analysis of a Buckwald-Hartwig amination: reaction for pharmaceutical production

DEFF Research Database (Denmark)

Christensen, Henrik; Kiil, Søren; Dam-Johansen, Kim

The Buchwald-Hartwig amination reaction is widely used in the production of N-arylated amines in the pharmaceutical industry. The reaction is betweenan aryl halogen and a primary or secondary amine in the presence of a base and a homogeneous catalyst giving the desired N-arylated amine. Due to mild...... is to increase the understanding of the chem­ical reaction mechanisms and kinetics for the Buchwald-Hartwig amination reaction. Also, to develop methods for application of these mechanisms and kinetics to optimize and scale up an organic synthesis to an industrial phar­maceutical production. The Buchwald...

Solvent-free functionalization of carbon nanotube buckypaper with amines

International Nuclear Information System (INIS)

Basiuk, Elena V.; Ramírez-Calera, Itzel J.; Meza-Laguna, Victor; Abarca-Morales, Edgar; Pérez-Rey, Luis A.; Re, Marilena; Prete, Paola; Lovergine, Nico

2015-01-01

Graphical abstract: - Abstract: We demonstrate the possibility of fast and efficient solvent-free functionalization of buckypaper (BP) mats prefabricated from oxidized multiwalled carbon nanotubes (MWCNTs-ox), by using three representative amines of different structure: one monofunctional aliphatic amine, octadecylamine (ODA), one monofunctional aromatic amine, 1-aminopyrene (AP), and one aromatic diamine, 1,5-diaminonaphthalene (DAN). The functionalization procedure, which relies on the formation of amide bonds with carboxylic groups of MWCNTs-ox, is performed at 150–180 °C under reduced pressure and takes about 4 h including auxiliary degassing. The amine-treated BP samples (BP-ODA, BP-AP and BP-DAN, respectively) were characterized by means of a variety of analytical techniques such as Fourier-transform infrared and Raman spectroscopy, thermogravimetric and differential thermal analysis, scanning and transmission electron microscopy, scanning helium ion microscopy, and atomic force microscopy. The highest amine content was found for BP-ODA, and the lowest one was observed for BP-DAN, with a possible contribution of non-covalently bonded amine molecules in all three cases. Despite of some differences in spectral and morphological characteristics for amine-functionalized BP samples, they have in common a dramatically increased stability in water as compared to pristine BP and, on the other hand, a relatively invariable electrical conductivity.

Silane surface modification for improved bioadhesion of esophageal stents

Science.gov (United States)

Karakoy, Mert; Gultepe, Evin; Pandey, Shivendra; Khashab, Mouen A.; Gracias, David H.

2014-08-01

Stent migration occurs in 10-40% of patients who undergo placement of esophageal stents, with higher migration rates seen in those treated for benign esophageal disorders. This remains a major drawback of esophageal stent therapy. In this paper, we propose a new surface modification method to increase the adhesion between self-expandable metallic stents (SEMS) and tissue while preserving their removability. Taking advantage of the well-known affinity between epoxide and amine terminated silane coupling agents with amine and carboxyl groups that are abundant in proteins and related molecules in the human body; we modified the surfaces of silicone coated esophageal SEMS with these adhesive self-assembled monolayers (SAMs). We utilized vapor phase silanization to modify the surfaces of different substrates including PDMS strips and SEMS, and measured the force required to slide these substrates on a tissue piece. Our results suggest that surface modification of esophageal SEMS via covalent attachment of protein-binding coupling agents improves adhesion to tissue and could offer a solution to reduce SEMS migration while preserving their removability.

Crystal Structure of Bicc1 SAM Polymer and Mapping of Interactions between the Ciliopathy-Associated Proteins Bicc1, ANKS3, and ANKS6.

Science.gov (United States)

Rothé, Benjamin; Leettola, Catherine N; Leal-Esteban, Lucia; Cascio, Duilio; Fortier, Simon; Isenschmid, Manuela; Bowie, James U; Constam, Daniel B

2018-02-06

Head-to-tail polymers of sterile alpha motifs (SAM) can scaffold large macromolecular complexes. Several SAM-domain proteins that bind each other are mutated in patients with cystic kidneys or laterality defects, including the Ankyrin (ANK) and SAM domain-containing proteins ANKS6 and ANKS3, and the RNA-binding protein Bicc1. To address how their interactions are regulated, we first determined a high-resolution crystal structure of a Bicc1-SAM polymer, revealing a canonical SAM polymer with a high degree of flexibility in the subunit interface orientations. We further mapped interactions between full-length and distinct domains of Bicc1, ANKS3, and ANKS6. Neither ANKS3 nor ANKS6 alone formed macroscopic homopolymers in vivo. However, ANKS3 recruited ANKS6 to Bicc1, and the three proteins together cooperatively generated giant macromolecular complexes. Thus, the giant assemblies are shaped by SAM domains, their flanking sequences, and SAM-independent protein-protein and protein-mRNA interactions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Fluorinated Amine Stereotriads via Allene Amination.

Science.gov (United States)

Liu, Lu; Gerstner, Nels C; Oxtoby, Lucas J; Guzei, Ilia A; Schomaker, Jennifer M

2017-06-16

The incorporation of fluorine into organic scaffolds often improves the bioactivity of pharmaceutically relevant compounds. C-F/C-N/C-O stereotriad motifs are prevalent in antivirals, neuraminidase inhibitors, and modulators of androgen receptors, but are challenging to install. An oxidative allene amination strategy using Selectfluor rapidly delivers triply functionalized triads of the form C-F/C-N/C-O, exhibiting good scope and diastereoselectivity for all syn products. The resulting stereotriads are readily transformed into fluorinated pyrrolidines and protected α-, β-, and γ-amino acids.

Graphene/multi-walled carbon nanotubes functionalized with an amine-terminated ionic liquid for determination of (Z)-3-(chloromethylene)-6-fluorothiochroman-4-one in urine.

Science.gov (United States)

Chen, Huanhuan; Yuan, Yanan; Xiang, Can; Yan, Hongyuan; Han, Yehong; Qiao, Fengxia

2016-11-25

A new type of amine-terminated-ionic-liquid-functionalized graphene/multi-walled carbon nanotubes hybrid material (IL-G/MWCNTs) was synthesized and used as an adsorbent in miniaturized pipette tip solid-phase extraction (PT-SPE) coupled with liquid chromatography for the isolation and determination of (Z)-3-(chloromethylene)-6-fluorothiochroman-4-one (CMFT) in urine. Parameters for the preparation of IL-G/MWCNTs and the PT-SPE procedure, including the mass ratio of graphene oxide and oxidized multi-walled carbon nanotubes, the mass ratio of graphene oxide and the ionic liquid, and the type and volume of washing and elution solvents were optimized to achieve higher extraction efficiency. Good linearity of the method was achieved in the range 0.03-5.0μgmL -1 with a coefficient of determination (r 2 ) of 0.9999. The limits of detection and quantification were 0.009 and 0.030μgmL -1 , respectively. The intra- and inter-day precisions, expressed as relative standard deviations (RSDs), were evaluated by performing replicate analyses of samples spiked at 0.1μgmL -1 on the same day (n=6) and over three consecutive days, and were 4.8 and 5.5%, respectively. Recoveries between 73.9 and 93.9% were obtained at three spiking levels, with RSDs≤7.9%. Five batches of the adsorbent were investigated to confirm the reliability of the preparation method. Copyright © 2016 Elsevier B.V. All rights reserved.

Evidence for Perchlorates and the Origin of Chlorinated Hydrocarbons Detected by SAM at the Rocknest Aeolian Deposit in Gale Crater

Science.gov (United States)

Glavin, Daniel P.; Freissinet, Caroline; Miller, Kristen E.; Eigenbrode, Jennifer L.; Brunner, Anna E.; Buch, Arnaud; Sutter, Brad; Archer, P. Douglas, Jr.; Atreya, Sushil K.; Brinckerhoff, William B.;

Evaluation of amine inhibitors for suitability as crevice buffering agents

International Nuclear Information System (INIS)

Jayaweera, P.; Hettiarachchi, S.

1994-03-01

This report describes the results of a research effort to evaluate the suitability of some selected amines and amino acids as a crevice-buffering agents in pressurized water reactor (PWR) steam generators. The amines may be useful for buffering acid crevices, and the amino acids, because they contain both acidic and basic groups, may be useful for acidic and caustic crevices. Five commercially available amines and two amino acids were studied during this research. The study involved (1) the hydrolysis of these commercially available amines and amino acids, including measurement of their kinetics of decomposition, in simulated steam generator bulk water at 290 C, and (2) determination of their thermal stability in a simulated crevice environment. The study showed that, although the high-molecular-weight amines undergo hydrothermal decomposition, they have a better buffering capacity than their low-molecular-weight counterparts at 290 C. The amines provide effective crevice buffering by increasing the pH of the crevice solution by as much as 2.84 and to 4.24 units in the experimental setup used in this program. It was concluded that polyamines provide excellent buffering of the simulated crevice environment at 290 C and morpholine remains the best low-molecular-weight amine investigated. However, detailed volatility studies of the amines were not considered in this work. Such data would be needed before in-plant testing to ensure that the amines can concentrate in steam generator crevices to the levels assumed in this study

New potential of the reductive alkylation of amines

International Nuclear Information System (INIS)

Gusak, K N; Ignatovich, Zh V; Koroleva, E V

2015-01-01

Available data on the reductive alkylation of amines with carbonyl compounds — a key method for the preparation of secondary and tertiary amines — are described systematically. The review provides information on the relevant reducing agents and catalysts and on the use of chiral catalysts in stereo- and enantiocontrolled reactions of amine synthesis. The effect of the reactant and catalyst structures on the reaction rates and chemo- and stereo(enantio)selectivity is considered. The bibliography includes 156 references

Poly(Amido Amine)s Containing Agmatine and Butanol Side Chains as Efficient Gene Carriers.

Science.gov (United States)

Won, Young-Wook; Ankoné, Marc; Engbersen, Johan F J; Feijen, Jan; Kim, Sung Wan

2016-04-01

A new type of bioreducible poly(amido amine) copolymer is synthesized by the Michael addition polymerization of cystamine bisacrylamide (CBA) with 4-aminobutylguanidine (agmatine, AGM) and 4-aminobutanol (ABOL). Since the positively charged guanidinium groups of AGM and the hydroxybutyl groups of ABOL in the side chains have shown to improve the overall transfection efficiency of poly(amido amine)s, it is hypothesized that poly(CBA-ABOL/AGM) synthesized at the optimal ratio of both components would result in high transfection efficiency and minimal toxicity. In this study, a series of the poly(CBA-ABOL/AGM) copolymers is synthesized as gene carriers. The polymers are characterized and luciferase transfection efficiencies of the polymers in various cell lines are investigated to select the ideal ratio between AGM and ABOL. The poly(CBA-ABOL/AGM) containing 80% AGM and 20% ABOL has shown the best transfection efficiency with the lowest cytotoxicity, indicating that this polymer is very promising as a potent and nontoxic gene carrier. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A Mild and Green Route for Regio-selective Amination of Oxiranes Using Nanomagnetic Supported Ferrous Ion as a Solid Lewis Acid Catalyst in Water

Directory of Open Access Journals (Sweden)

Fariborz Mansouri

2016-07-01

Full Text Available A mild, green and highly efficient route for regio-selective amination of oxiranes was developed via incorporation of Mn(II, Fe(II, Co(II, Ni(II, Cu(II and Zn(II cations onto the surface of hydroxyapatite-encapsulated γ-Fe2O3 nanoparticles (γ-Fe2O3@HAp. Among six magnetically recoverable catalytic systems denoted as [γ-Fe2O3@HAp-MII], the catalyst in which M designated as Fe(II showed the best efficiency as well as regio-selectivity in amination of oxiranes under an ambient reaction condition. A wide variety of aromatic and aliphatic amines were reacted with epoxides using magnetically separable iron catalyst to give the corresponding amino alcohols in excellent yields and selectivities in water as solvent at room temperature. In addition, recovery of the catalyst was successfully carried out in subsequent runs without any decrease in activity even after 5 runs. High regio-selectivity toward terminal ring-opening, efficient catalyst reusability using simple magnetic separation, high yields, simplicity in operation and diversity for various substrates are of advantages of this study.

Fluorescence quenching of Rhodamine B base by two amines

Science.gov (United States)

Bakkialakshmi, S.; Selvarani, P.; Chenthamarai, S.

2013-03-01

Fluorescence quenching of Rhodamine B base (RhB) in DMF solution has been studied at different concentrations of the amine Triethyl amine (TEA) and n-butyl amine (NBA) at room temperature. It has been observed that the fluorescence intensity of RhB decrease with increase in the concentration of the TEA and NBA. It has been observed that the quenching due to amines proceeds via dynamic quenching process. The rate constants for the quenching process have been calculated using Stern-Volmer equation. Time resolved fluorescence study and 1H NMR spectral study have also been carried out and discussed.

Catalyst- and Reagent-free Electrochemical Azole C-H Amination.

Science.gov (United States)

Qiu, Youai; Struwe, Julia; Meyer, Tjark H; Oliveira, Joao Carlos Agostinho Carlos Agostinho; Ackermann, Lutz

2018-06-14

Catalyst-, and chemical oxidant-free electrochemical azole C-H aminations were accomplished via cross-dehydrogenative C-H/N-H functionalization. The catalyst-free electrochemical C-H amination proved feasible on azoles with high levels of efficacy and selectivity, avoiding the use of stoichiometric oxidants under ambient conditions. Likewise, the C(sp3)-H nitrogenation proved viable under otherwise identical conditions. The dehydrogenative C-H amination featured ample scope, including cyclic and acyclic aliphatic amines as well as anilines, and employed sustainable electricity as the sole oxidant. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Potensi Tinggalan Arkeologis di Kawasan Bandar Udara Sam Ratulangi Manado: Upaya Pelestarian, Pemanfaatan, dan Pengembangan bagi Masyarakat

Directory of Open Access Journals (Sweden)

Irfanuddin W. Marzuki

2016-08-01

Full Text Available The area of Sam Ratulangi airport’s Manado has archaeological heritage which has been know as it is closed for public. This research used descriptive method, using inductive reasoning. Meanwhile, the analysis method used morphologyl, technology, and contextual analysis. This research aimed to find out the potential of archaeological heritage in Sam Ratulangi airport area of Manado. In addition to its strategy of preservation the haritage included veilbox, bungker, and waruga. The preservation can be conducted by doing protection, development, and utilization. The preservation both physical and non physical protection. The effort for its development and utilization was conducted for the purpose of science, education, culture, and tourism. Kawasan Bandar Udara Sam Ratulangi Manado mempunyai potensi tinggalan arkeologis yang selama ini tidak diketahui masyarakat luas, dikarenakan letak tinggalan yang berada dalam kawasan tertutup untuk umum. Penelitian menggunakan metode deskriptif dengan penalaran induktif. Metode analisis menggunakan analisis morfologi, teknologi dan kontekstual. Tujuan penelitian untuk mengetahui potensi tinggalan arkeologis yang terdapat di kawasan Bandar Udara Sam Ratulangi dan strategi pelestariannya. Tinggalan arkeologis yang terdapat di kawasan Bandar Udara Sam Ratulangi meliputi veilbox, bungker, dan waruga. Upaya pelestarian dapat dilakukan dengan cara perlindungan, pengembangan dan pemanfaatan. Upaya perlindungan meliputi perlindungan secara fisik dan non fisik. Upaya pengembangan dan pemanfaatan dilakukan untuk kepentingan ilmu pengetahuan, pendidikan, kebudayaan dan pariwisata.

Carbon tax effects on the poor: a SAM-based approach

Science.gov (United States)

Chapa, Joana; Ortega, Araceli

2017-09-01

A SAM-based price model for Mexico is developed in order to assess the effects of the carbon tax, which was part of the fiscal reform approved in 2014. The model is formulated based on a social accounting matrix (SAM) that distinguishes households by the official poverty condition and geographical area. The main results are that the sector that includes coke, refined petroleum and nuclear fuel shows the highest price increase due to the direct impact of the carbon tax; in addition, air transport and inland transport are the most affected sectors, in an indirect manner, because both employ inputs from the former sector. Also, it is found that welfare diminishes more in the rural strata than in the urban one. In the urban area, the carbon tax is regressive: the negative impact of carbon tax on family welfare is greater on the poorest families.

FIGURAL FORMS OF KNOWLEDGE: A STUDY OF THE SHORT PROSE OF SAM SHEPARD

Directory of Open Access Journals (Sweden)

RICARDO DA SILVA SOBREIRA

2008-11-01

Full Text Available ABSTRACTThe paratactical style and the indeterminacies are literary strategies that resistthe conventional impulse of totalizing the elements projected by the text, becauseinstead of selecting the aspects of reality and subordinating the images andperceptions into a hierarchy, the use of these techniques favors the juxtapositionof multiple perspectives and the frustration of narrative closure. Thus, the useof parataxis and indeterminacies in the collection of short stories Great Dreamof Heaven (2002, by the American author Sam Shepard, tends to challenge theprocess of meaning production through the progressive erasure of narrative“certainties”.KEY WORDS: Postmodern, indeterminacy, parataxis, narrative, Sam Shepard.  

BIOGENIC AMINES CONTENT IN SELECTED WINES DURING WINEMAKING

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Radka Flasarová

2012-02-01

Full Text Available The aim of this study was to describe the development of selected biogenic amines (histamine; tyramine; phenylethylamine; putrescine; agmatine; and cadaverine during the winemaking in 10 selected species grown in Central Europe in 2008. The analysis was performed using ion-exchange chromatography by the sodium-citrate buffers with the post-column ninhydrin derivatization and photometric detection. A comparison of the content of biogenic amines in red and wine varieties showed that red wines have higher concentrations of biogenic amines.

Biogenic amines in dry fermented sausages: a review.

Science.gov (United States)

Suzzi, Giovanna; Gardini, Fausto

2003-11-15

Biogenic amines are compounds commonly present in living organisms in which they are responsible for many essential functions. They can be naturally present in many foods such as fruits and vegetables, meat, fish, chocolate and milk, but they can also be produced in high amounts by microorganisms through the activity of amino acid decarboxylases. Excessive consumption of these amines can be of health concern because their not equilibrate assumption in human organism can generate different degrees of diseases determined by their action on nervous, gastric and intestinal systems and blood pressure. High microbial counts, which characterise fermented foods, often unavoidably lead to considerable accumulation of biogenic amines, especially tyramine, 2-phenylethylamine, tryptamine, cadaverine, putrescine and histamine. However, great fluctuations of amine content are reported in the same type of product. These differences depend on many variables: the quali-quantitative composition of microbial microflora, the chemico-physical variables, the hygienic procedure adopted during production, and the availability of precursors. Dry fermented sausages are worldwide diffused fermented meat products that can be a source of biogenic amines. Even in the absence of specific rules and regulations regarding the presence of these compounds in sausages and other fermented products, an increasing attention is given to biogenic amines, especially in relation to the higher number of consumers with enhanced sensitivity to biogenic amines determined by the inhibition of the action of amino oxidases, the enzymes involved in the detoxification of these substances. The aim of this paper is to give an overview on the presence of these compounds in dry fermented sausages and to discuss the most important factors influencing their accumulation. These include process and implicit factors as well as the role of starter and nonstarter microflora growing in the different steps of sausage production

Direct α-C-H bond functionalization of unprotected cyclic amines

Science.gov (United States)

Chen, Weijie; Ma, Longle; Paul, Anirudra; Seidel, Daniel

2018-02-01

Cyclic amines are ubiquitous core structures of bioactive natural products and pharmaceutical drugs. Although the site-selective abstraction of C-H bonds is an attractive strategy for preparing valuable functionalized amines from their readily available parent heterocycles, this approach has largely been limited to substrates that require protection of the amine nitrogen atom. In addition, most methods rely on transition metals and are incompatible with the presence of amine N-H bonds. Here we introduce a protecting-group-free approach for the α-functionalization of cyclic secondary amines. An operationally simple one-pot procedure generates products via a process that involves intermolecular hydride transfer to generate an imine intermediate that is subsequently captured by a nucleophile, such as an alkyl or aryl lithium compound. Reactions are regioselective and stereospecific and enable the rapid preparation of bioactive amines, as exemplified by the facile synthesis of anabasine and (-)-solenopsin A.

Sponges with covalently tethered amines for high-efficiency carbon capture

KAUST Repository

Qi, Genggeng

2014-12-12

© 2014 Macmillan Publishers Limited. All rights reserved. Adsorption using solid amine sorbents is an attractive emerging technology for energy-efficient carbon capture. Current syntheses for solid amine sorbents mainly based on physical impregnation or grafting-to methods (for example, aminosilane-grafting) lead to limited sorbent performance in terms of stability and working capacity, respectively. Here we report a family of solid amine sorbents using a grafting-from synthesis approach and synthesized by cationic polymerization of oxazolines on mesoporous silica. The sorbent with high amount of covalently tethered amines shows fast adsorption rate, high amine efficiency and sorbent capacity well exceeding the highest value reported to date for lowerature carbon dioxide sorbents under simulated flue gas conditions. The demonstrated efficiency of the new amine-immobilization chemistry may open up new avenues in the development of advanced carbon dioxide sorbents, as well as other nitrogen-functionalized systems.

Sequential metabolism of secondary alkyl amines to metabolic-intermediate complexes: opposing roles for the secondary hydroxylamine and primary amine metabolites of desipramine, (s)-fluoxetine, and N-desmethyldiltiazem.

Science.gov (United States)

Hanson, Kelsey L; VandenBrink, Brooke M; Babu, Kantipudi N; Allen, Kyle E; Nelson, Wendel L; Kunze, Kent L

2010-06-01

Three secondary amines desipramine (DES), (S)-fluoxetine [(S)-FLX], and N-desmethyldiltiazem (MA) undergo N-hydroxylation to the corresponding secondary hydroxylamines [N-hydroxydesipramine, (S)-N-hydroxyfluoxetine, and N-hydroxy-N-desmethyldiltiazem] by cytochromes P450 2C11, 2C19, and 3A4, respectively. The expected primary amine products, N-desmethyldesipramine, (S)-norfluoxetine, and N,N-didesmethyldiltiazem, are also observed. The formation of metabolic-intermediate (MI) complexes from these substrates and metabolites was examined. In each example, the initial rates of MI complex accumulation followed the order secondary hydroxylamine > secondary amine > primary amine, suggesting that the primary amine metabolites do not contribute to formation of MI complexes from these secondary amines. Furthermore, the primary amine metabolites, which accumulate in incubations of the secondary amines, inhibit MI complex formation. Mass balance studies provided estimates of the product ratios of N-dealkylation to N-hydroxylation. The ratios were 2.9 (DES-CYP2C11), 3.6 [(S)-FLX-CYP2C19], and 0.8 (MA-CYP3A4), indicating that secondary hydroxylamines are significant metabolites of the P450-mediated metabolism of secondary alkyl amines. Parallel studies with N-methyl-d(3)-desipramine and CYP2C11 demonstrated significant isotopically sensitive switching from N-demethylation to N-hydroxylation. These findings demonstrate that the major pathway to MI complex formation from these secondary amines arises from N-hydroxylation rather than N-dealkylation and that the primary amines are significant competitive inhibitors of MI complex formation.

Biogenic amines and radiosensitivity of solitary cells

International Nuclear Information System (INIS)

Goncharenko, E.N.

1978-01-01

Different stability of cells to ionizing radiation is considered from a position of the ''elevated biochemical radioresistance background'' concept. Experimental evidence presented indicates an important role of endogenic amines (serotonin and histamine) possessing radioprotector properties in the cell radioresistance formation. The concept about their effect as being solely a result of circulatory hypoxia is critically discussed. The experimental results favor the existence of a ''cellular'' component, along with the ''hypoxic'' one, in the mechanism of action of biogenic amines. These compounds can affect the initial stages of peroxide oxidation of lipids, thereby favoring a less intensive oxidation induced by radiation. Biogenic amines can also exert influence on the cyclic nucleotide system

Ni-Catalyzed Carbon-Carbon Bond-Forming Reductive Amination.

Science.gov (United States)

Heinz, Christoph; Lutz, J Patrick; Simmons, Eric M; Miller, Michael M; Ewing, William R; Doyle, Abigail G

2018-02-14

This report describes a three-component, Ni-catalyzed reductive coupling that enables the convergent synthesis of tertiary benzhydryl amines, which are challenging to access by traditional reductive amination methodologies. The reaction makes use of iminium ions generated in situ from the condensation of secondary N-trimethylsilyl amines with benzaldehydes, and these species undergo reaction with several distinct classes of organic electrophiles. The synthetic value of this process is demonstrated by a single-step synthesis of antimigraine drug flunarizine (Sibelium) and high yielding derivatization of paroxetine (Paxil) and metoprolol (Lopressor). Mechanistic investigations support a sequential oxidative addition mechanism rather than a pathway proceeding via α-amino radical formation. Accordingly, application of catalytic conditions to an intramolecular reductive coupling is demonstrated for the synthesis of endo- and exocyclic benzhydryl amines.

Potential occupational risk of amines in carbon capture for power generation.

Science.gov (United States)

Gentry, P Robinan; House-Knight, Tamara; Harris, Angela; Greene, Tracy; Campleman, Sharan

2014-08-01

While CO2 capture and storage (CCS) technology has been well studied in terms of its efficacy and cost of implementation, there is limited available data concerning the potential for occupational exposure to amines, mixtures of amines, or degradation of by-products from the CCS process. This paper is a critical review of the available data concerning the potential effects of amines and CCS-degradation by-products. A comprehensive review of the occupational health and safety issues associated with exposure to amines and amine by-products at CCS facilities was performed, along with a review of the regulatory status and guidelines of amines, by-products, and CCS process vapor mixtures. There are no specific guidelines or regulations regarding permissible levels of exposure via air for amines and degradation products that could form atmospheric oxidation of amines released from post-combustion CO2 capture plants. While there has been a worldwide effort to develop legal and regulatory frameworks for CCS, none are directly related to occupational exposures. By-products of alkanolamine degradation may pose the most significant health hazard to workers in CCS facilities, with several aldehydes, amides, nitramines, and nitrosamines classified as either known or potential/possible human carcinogens. The absence of large-scale CCS facilities; absence and unreliability of reported data in the literature from pilot facilities; and proprietary amine blends make it difficult to estimate potential amine exposures and predict formation and exposure to degradation products.

A viral protein promotes host SAMS1 activity and ethylene production for the benefit of virus infection.

Science.gov (United States)

Zhao, Shanshan; Hong, Wei; Wu, Jianguo; Wang, Yu; Ji, Shaoyi; Zhu, Shuyi; Wei, Chunhong; Zhang, Jinsong; Li, Yi

2017-10-10

Ethylene plays critical roles in plant development and biotic stress response, but the mechanism of ethylene in host antiviral response remains unclear. Here, we report that Rice dwarf virus (RDV) triggers ethylene production by stimulating the activity of S-adenosyl-L-methionine synthetase (SAMS), a key component of the ethylene synthesis pathway, resulting in elevated susceptibility to RDV. RDV-encoded Pns11 protein specifically interacted with OsSAMS1 to enhance its enzymatic activity, leading to higher ethylene levels in both RDV-infected and Pns11-overexpressing rice. Consistent with a counter-defense role for ethylene, Pns11-overexpressing rice, as well as those overexpressing OsSAMS1 , were substantially more susceptible to RDV infection, and a similar effect was observed in rice plants treated with an ethylene precursor. Conversely, OsSAMS1- knockout mutants, as well as an osein2 mutant defective in ethylene signaling, resisted RDV infection more robustly. Our findings uncover a novel mechanism which RDV manipulates ethylene biosynthesis in the host plants to achieve efficient infection.

The chemistry of amine radical cations produced by visible light photoredox catalysis

Directory of Open Access Journals (Sweden)

Jie Hu

2013-10-01

Full Text Available Amine radical cations are highly useful reactive intermediates in amine synthesis. They have displayed several modes of reactivity leading to some highly sought-after synthetic intermediates including iminium ions, α-amino radicals, and distonic ions. One appealing method to access amine radical cations is through one-electron oxidation of the corresponding amines under visible light photoredox conditions. This approach and subsequent chemistries are emerging as a powerful tool in amine synthesis. This article reviews synthetic applications of amine radical cations produced by visible light photocatalysis.

Solution structure of the receptor tyrosine kinase EphB2 SAM domain and identification of two distinct homotypic interaction sites.

OpenAIRE

Smalla, M.; Schmieder, P.; Kelly, M.; Ter Laak, A.; Krause, G.; Ball, L.; Wahl, M.; Bork, P.; Oschkinat, H.

1999-01-01

The sterile alpha motif (SAM) is a protein interaction domain of around 70 amino acids present predominantly in the N- and C-termini of more than 60 diverse proteins that participate in signal transduction and transcriptional repression. SAM domains have been shown to homo- and hetero-oligomerize and to mediate specific protein-protein interactions. A highly conserved subclass of SAM domains is present at the intracellular C-terminus of more than 40 Eph receptor tyrosine kinases that are invo...

Application of ultraviolet, ozone, and advanced oxidation treatments to washwaters to destroy nitrosamines, nitramines, amines, and aldehydes formed during amine-based carbon capture.

Science.gov (United States)

Shah, Amisha D; Dai, Ning; Mitch, William A

2013-03-19

Although amine-based CO(2) absorption is a leading contender for full-scale postcombustion CO(2) capture at power plants, concerns have been raised about the potential release of carcinogenic N-nitrosamines and N-nitramines formed by reaction of exhaust gas NO(x) with the amines. Experiments with a laboratory-scale pilot unit suggested that washwater units meant to scrub contaminants from absorber unit exhaust could potentially serve as a source of N-nitrosamines via reactions of residual NO(x) with amines accumulating in the washwater. Dosage requirements for the continuous treatment of the washwater recycle line with ultraviolet (UV) light for destruction of N-nitrosamines and N-nitramines, and with ozone or hydroxyl radical-based advanced oxidation processes (AOPs) for destruction of amines and aldehydes, were evaluated. Although amine destruction. Ozone achieved 90% amine removal in washwaters at 5-12 molar excess of ozone, indicating transferred dosage levels of ∼100 mg/L for 90% removal in a first-stage washwater unit, but likely only ∼10 mg/L if applied to a second-stage washwater. Accurate dosage and cost estimates would require pilot testing to capture synergies between UV and ozone treatments.

Mesoporous amine-bridged polysilsesquioxane for CO2 capture

KAUST Repository

Qi, Genggeng; Fu, Liling; Duan, Xiaonan; Choi, Brian Hyun; Abraham, Michael; Giannelis, Emmanuel P.

2011-01-01

A novel class of amine-supported sorbents based on amine-bridged mesoporous polysilsesquioxane was developed via a simple one-pot sol-gel process. The new sorbent allows the incorporation of a large amount of active groups without sacrificing

Enantioselective catalytic syntheses of alpha-branched chiral amines

DEFF Research Database (Denmark)

Brase, S.; Baumann, T.; Dahmen, S.

2007-01-01

Chiral amines play a pivotal role in fine chemical and natural product syntheses and the design of novel materials.......Chiral amines play a pivotal role in fine chemical and natural product syntheses and the design of novel materials....

Effects of dietary amines on the gut and its vasculature.

Science.gov (United States)

Broadley, Kenneth J; Akhtar Anwar, M; Herbert, Amy A; Fehler, Martina; Jones, Elen M; Davies, Wyn E; Kidd, Emma J; Ford, William R

2009-06-01

Trace amines, including tyramine and beta-phenylethylamine (beta-PEA), are constituents of many foods including chocolate, cheeses and wines and are generated by so-called 'friendly' bacteria such as Lactobacillus, Lactococcus and Enterococcus species, which are found in probiotics. We therefore examined whether these dietary amines could exert pharmacological effects on the gut and its vasculature. In the present study we examined the effects of tyramine and beta-PEA on the contractile activity of guinea-pig and rat ileum and upon the isolated mesenteric vasculature and other blood vessels. Traditionally, these amines are regarded as sympathomimetic amines, exerting effects through the release of noradrenaline from sympathetic nerve endings, which should relax the gut. A secondary aim was therefore to confirm this mechanism of action. However, contractile effects were observed in the gut and these were independent of noradrenaline, acetylcholine, histamine and serotonin receptors. They were therefore probably due to the recently described trace amine-associated receptors. These amines relaxed the mesenteric vasculature. In contrast, the aorta and coronary arteries were constricted, a response that was also independent of a sympathomimetic action. From these results, we propose that after ingestion, trace amines could stimulate the gut and improve intestinal blood flow. Restriction of blood flow elsewhere diverts blood to the gut to aid digestion. Thus, trace amines in the diet may promote the digestive process through stimulation of the gut and improved gastrointestinal circulation.

The mysterious trace amines: protean neuromodulators of synaptic transmission in mammalian brain.

Science.gov (United States)

Burchett, Scott A; Hicks, T Philip

2006-08-01

The trace amines are a structurally related group of amines and their isomers synthesized in mammalian brain and peripheral nervous tissues. They are closely associated metabolically with the dopamine, noradrenaline and serotonin neurotransmitter systems in mammalian brain. Like dopamine, noradrenaline and serotonin the trace amines have been implicated in a vast array of human disorders of affect and cognition. The trace amines are unique as they are present in trace concentrations, exhibit high rates of metabolism and are distributed heterogeneously in mammalian brain. While some are synthesized in their parent amine neurotransmitter systems, there is also evidence to suggest other trace amines may comprise their own independent neurotransmitter systems. A substantial body of evidence suggests that the trace amines may play very significant roles in the coordination of biogenic amine-based synaptic physiology. At high concentrations, they have well-characterized presynaptic "amphetamine-like" effects on catecholamine and indolamine release, reuptake and biosynthesis; at lower concentrations, they possess postsynaptic modulatory effects that potentiate the activity of other neurotransmitters, particularly dopamine and serotonin. The trace amines also possess electrophysiological effects that are in opposition to these neurotransmitters, indicating to some researchers the existence of receptors specific for the trace amines. While binding sites or receptors for a few of the trace amines have been advanced, the absence of cloned receptor protein has impeded significant development of their detailed mechanistic roles in the coordination of catecholamine and indolamine synaptic physiology. The recent discovery and characterization of a family of mammalian G protein-coupled receptors responsive to trace amines such as beta-phenylethylamine, tyramine, and octopamine, including socially ingested psychotropic drugs such as amphetamine, 3,4-methylenedioxymethamphetamine, N

Smoking-Attributable Mortality, Morbidity, and Economic Costs (SAMMEC) - Smoking-Attributable Mortality (SAM)

Data.gov (United States)

U.S. Department of Health & Human Services — 2005-2009. SAMMEC - Smoking-Attributable Mortality, Morbidity, and Economic Costs. Smoking-attributable mortality (SAM) is the number of deaths caused by cigarette...

Carbon Dioxide-Mediated C(sp3)-H Arylation of Amine Substrates.

Science.gov (United States)

Kapoor, Mohit; Liu, Daniel; Young, Michael C

2018-05-25

Elaborating amines via C-H functionalization has been an important area of research over the past decade but has generally relied on an added directing group or sterically hindered amine approach. Since free-amine-directed C(sp 3 )-H activation is still primarily limited to cyclization reactions and to improve the sustainability and reaction scope of amine-based C-H activation, we present a strategy using CO 2 in the form of dry ice that facilitates intermolecular C-H arylation. This methodology has been used to enable an operationally simple procedure whereby 1° and 2° aliphatic amines can be arylated selectively at their γ-C-H positions. In addition to potentially serving as a directing group, CO 2 has also been demonstrated to curtail the oxidation of sensitive amine substrates.

Decomposition of some amines and amino acids in steam generator environments

International Nuclear Information System (INIS)

Jayaweera, P.; Hettiarachchi, S.; Millett, P.J.

1994-01-01

Hydrothermal decomposition rate constants and high temperature pH values of some selected high-molecular weight amines and amino acids were measured under simulated steam generator conditions. These amines and amino acids were evaluated as potential crevice buffering agents for steam generator applications in pressurized water reactors. The study showed that, although the high molecular weight amines undergo hydrothermal decomposition, they have a better buffer capacity than their low molecular weight counterparts at 290 C. The amines provide effective crevice buffering by increasing the pH of the simulated crevice solution by as much as 2.84 to 4.24 units. However, volatility data for the amines and amino acids are needed before in-plant testing to ensure that amines can concentrate sufficiently in steam generator crevices to provide effective buffering

Uranium diphosphonates templated by interlayer organic amines

International Nuclear Information System (INIS)

Nelson, Anna-Gay D.; Alekseev, Evgeny V.; Albrecht-Schmitt, Thomas E.; Ewing, Rodney C.

2013-01-01

The hydrothermal treatment of uranium trioxide and methylenediphosphonic acid with a variety of amines (2,2-dipyridyl, triethylenediamine, ethylenediamine, and 1,10-phenanthroline) at 200 °C results in the crystallization of a series of layered uranium diphosphonate compounds, [C 10 H 9 N 2 ]{UO 2 (H 2 O)[CH 2 (PO 3 )(PO 3 H)]} (Ubip2), [C 6 H 14 N 2 ]{(UO 2 ) 2 [CH 2 (PO 3 )(PO 3 H)] 2 ·2H 2 O} (UDAB), [C 2 H 10 N 2 ] 2 {(UO 2 ) 2 (H 2 O) 2 [CH 2 (PO 3 ) 2 ] 2 ·0.5H 2 O} (Uethyl), and [C 12 H 9 N 2 ]{UO 2 (H 2 O)[CH 2 (PO 3 )(PO 3 H)]} (Uphen). The crystal structures of the compounds are based on UO 7 units linked by methylenediphosphonate molecules to form two-dimensional anionic sheets in Ubip2 and UDAB, and one-dimensional anionic chains in Uethyl and Uphen, which are charge balanced by protonated amine molecules. Interaction of the amine molecules with phosphonate oxygens and water molecules results in extensive hydrogen bonding in the interlayer. These amine molecules serve both as structure-directing agents and charge-balancing cations for the anionic uranium phosphonate sheets and chains in the formation of the different coordination geometries and topologies of each structure. Reported herein are the syntheses, structural and spectroscopic characterization of the synthesized compounds. - Graphical abstract: The Raman spectra of the synthesized compounds and an illustration of the stacking of the layers with the diprotonated triethylenediamine molecules in [C 6 H 14 N 2 ]{(UO 2 ) 2 [CH 2 (PO 3 )(PO 3 H)] 2 ·2H 2 O} UDAB. Solvent water molecules are removed for clarity. The corresponding Raman spectra for the complexes synthesized is also shown. The structure is constructed from UO 7 pentagonal bipyramids (yellow), oxygen=red, phosphorus=magenta, carbon=black, and nitrogen=blue. Highlights: ► Organic amines act both as charge-balancing and as structure-directing agents. ► Extensive hydrogen bonding interactions with solvent water molecules and amines

Aqueous amine solution characterization for post-combustion CO_2 capture process

International Nuclear Information System (INIS)

El Hadri, Nabil; Quang, Dang Viet; Goetheer, Earl L.V.; Abu Zahra, Mohammad R.M.

2017-01-01

Highlights: • The CO_2 solubility of 30 aqueous amine solutions was measured at 30 wt% and 313.15 K. • The CO_2 loading of HMD is the highest, and that of TEA is the lowest. • 2DMAE, 3DMA1P, 1DMA2P, MDEA, TMPAD and 2EAE have a low heat of absorption with CO_2. • 2EAE can be used as an alternative to MEA in the CO_2 capture process. - Abstract: This article presents a thermodynamic and kinetic characterization of CO_2 absorption by 30 aqueous amine solutions. A solvent screening setup (S.S.S.) was used to find the CO_2 loading (α) for 30 different aqueous amine solutions (30 wt%) at a pressure of 1 bar with feed gas containing 15 vol% CO_2 and 85 vol% N_2 at 313.15 K to provide reliable absorber parameters. The structures of various amines (linear, non-linear, polyamines, sterically hindered, etc.) were tested and the S.S.S. results showed that hexamethylenediamine (HMD) has higher CO_2 loading at 1.35 moles of CO_2/mole of amine, and triethanolamine (TEA) has the lowest at 0.39 mole of CO_2/mole of amine. The heat of absorption indicates that MDEA has the lowest and HMD has the highest at −52.51 kJ/mole of CO_2 and −98.39 kJ/mole of CO_2, respectively. The combined data for the CO_2 loading and the absorption heat generated 6 amines that have good properties for the post-combustion CO_2 capture process in comparison with that of MEA. These amines are made up of one secondary amine (2-ethylaminoethanol, 2EAE) and 5 tertiary amines (N-methyldiethanolamine, MDEA, 1-dimethylamino-2-propanol, 1DMA2P, 2-dimethylaminoethanol, 2DMAE, 3-dimethylamino-1-propanol, 3DMA1P and N,N,N′,N′-tetramethyl-1,3-propanediamine, TMPDA). In comparison with the amine reference MEA (ΔH = −85.13 kJ/mole of CO_2 and α = 0.58 mole CO_2/mole of amine), the 6 amines have heats of absorption that are between −68.95 kJ/mole of CO_2 and −52.51 kJ/mole of CO_2, and their CO_2 loading is between 0.52 and 1.16 mole of CO_2/mole amine. The third important parameter, namely the

SAMS--a systems architecture for developing intelligent health information systems.

Science.gov (United States)

Yılmaz, Özgün; Erdur, Rıza Cenk; Türksever, Mustafa

2013-12-01

In this paper, SAMS, a novel health information system architecture for developing intelligent health information systems is proposed and also some strategies for developing such systems are discussed. The systems fulfilling this architecture will be able to store electronic health records of the patients using OWL ontologies, share patient records among different hospitals and provide physicians expertise to assist them in making decisions. The system is intelligent because it is rule-based, makes use of rule-based reasoning and has the ability to learn and evolve itself. The learning capability is provided by extracting rules from previously given decisions by the physicians and then adding the extracted rules to the system. The proposed system is novel and original in all of these aspects. As a case study, a system is implemented conforming to SAMS architecture for use by dentists in the dental domain. The use of the developed system is described with a scenario. For evaluation, the developed dental information system will be used and tried by a group of dentists. The development of this system proves the applicability of SAMS architecture. By getting decision support from a system derived from this architecture, the cognitive gap between experienced and inexperienced physicians can be compensated. Thus, patient satisfaction can be achieved, inexperienced physicians are supported in decision making and the personnel can improve their knowledge. A physician can diagnose a case, which he/she has never diagnosed before, using this system. With the help of this system, it will be possible to store general domain knowledge in this system and the personnel's need to medical guideline documents will be reduced.

Amine Functionalized Porous Network

KAUST Repository

Eddaoudi, Mohamed; Guillerm, Vincent; Weselinski, Lukasz Jan; Alkordi, Mohamed H.; Mohideen, Mohamed Infas Haja; Belmabkhout, Youssef

2015-01-01

Amine groups can be introduced in porous materials by a direct (one pot) or post-synthetic modification (PSM) process on aldehyde groups, and the resulting porous materials have increased gas affinity.

Amine Functionalized Porous Network

KAUST Repository

Eddaoudi, Mohamed

2015-05-28

Amine groups can be introduced in porous materials by a direct (one pot) or post-synthetic modification (PSM) process on aldehyde groups, and the resulting porous materials have increased gas affinity.

Monomers for thermosetting and toughening epoxy resins. [glycidyl amine derivatives, propargyl-containing amines, and mutagenic testing of aromatic diamines

Science.gov (United States)

Pratt, J. R.

1981-01-01

Eight glycidyl amines were prepared by alkylating the parent amine with epichlorohydrin to form chlorohydrin, followed by cyclization with aqueous NaOH. Three of these compounds contained propargyl groups with postcuring studies. A procedure for quantitatively estimating the epoxy content of these glycidyl amines was employed for purity determination. Two diamond carbonates and several model propargly compounds were prepared. The synthesis of three new diamines, two which contain propargyloxy groups, and another with a sec-butyl group is in progress. These materials are at the dinitro stage ready for the final hydrogenation step. Four aromatic diamines were synthesized for mutagenic testing purposes. One of these compounds rapidly decomposes on exposure to air.

Nitrile-functionalized tertiary amines as highly efficient and reversible SO2 absorbents

International Nuclear Information System (INIS)

Hong, Sung Yun; Kim, Heehwan; Kim, Young Jin; Jeong, Junkyo; Cheong, Minserk; Lee, Hyunjoo; Kim, Hoon Sik; Lee, Je Seung

2014-01-01

Highlights: • Nitrile-functionalized tertiary amines physically and reversibly absorb SO 2 . • Tertiary alkanolamines chemically and irreversibly absorb SO 2 through OH group. • SO 2 absorption modes were studied by spectroscopy and computational calculations. -- Abstract: Three different types of nitrile-functionalized amines, including 3-(N,N-diethylamino)propionitrile (DEAPN), 3-(N,N-dibutylamino)propionitrile (DBAPN), and N-methyl-N,N-dipropionitrile amine (MADPN) were synthesized, and their SO 2 absorption performances were evaluated and compared with those of hydroxy-functionalized amines such as N,N-diethyl-N-ethanol amine (DEEA), N,N-dibutyl-N-ethanol amine (DBEA), and N-methyl-N,N-diethanol amine (MDEA). Absorption–desorption cycle experiments clearly demonstrate that the nitrile-functionalized amines are more efficient than the hydroxy-functionalized amines in terms of absorption rate and regenerability. Computational calculations with DBEA and DBAPN revealed that DBEA bearing a hydroxyethyl group chemically interacts with SO 2 through oxygen atom, forming an ionic compound with a covalently bound -OSO 2 − group. On the contrary, DBAPN bearing a nitrile group physically interacts with SO 2 through the nitrogen and the hydrogen atoms of the two methylene groups adjacent to the amino and nitrile functionalities

Evolved Gas Analyses of the Murray Formation in Gale Crater, Mars: Results of the Curiosity Rover's Sample Analysis at Mars (SAM) Instrument

Science.gov (United States)

Sutter, B.; McAdam, A. C.; Rampe, E. B.; Thompson, L. M.; Ming, D. W.; Mahaffy, P. R.; Navarro-Gonzalez, R.; Stern, J. C.; Eigenbrode, J. L.; Archer, P. D.

2017-01-01

The Sample Analysis at Mars (SAM) instrument aboard the Mars Science Laboratory rover has analyzed 13 samples from Gale Crater. All SAM-evolved gas analyses have yielded a multitude of volatiles (e.g., H2O, SO2, H2S, CO2, CO, NO, O2, HCl) [1- 6]. The objectives of this work are to 1) Characterize recent evolved SO2, CO2, O2, and NO gas traces of the Murray formation mudstone, 2) Constrain sediment mineralogy/composition based on SAM evolved gas analysis (SAM-EGA), and 3) Discuss the implications of these results relative to understanding the geological history of Gale Crater.

Production of biogenic amines in "Salamini italiani alla cacciatora PDO".

Science.gov (United States)

Coı X0308 Sson, Jean Daniel; Cerutti, Caterina; Travaglia, Fabiano; Arlorio, Marco

2004-06-01

Various fermented and seasoned foods such as cheese, sauerkraut, wine, beer and meat products may contain biogenic amines. The aim of this paper was to describe the presence of some biogenic amines (histamine, tyramine, tryptamine, 2-phenylethylamine) in "Salamini italiani alla cacciatora PDO", a typical fermented-ripened dry sausage widely consumed in Italy. Total level of biogenic amines in commercial samples ranged from 71 to 586 mg kg(-1). The amine recovered in higher concentrations was tyramine (372 mg kg(-1)) followed by histamine (165 mg kg(-1)). The second aim of this work was the quality control of the production in order to determine the parameters influencing the presence of biogenic amines in ripened salami. Sausages sampled for analysis during production, manipulation and ripening showed the presence of tyramine (64.4 mg kg(-1)) only after 15 days of fermentation. All investigated biogenic amines were detected in "Salamini" after 21 days of fermentation. We suggest the control of biogenic as important tool to establish the better condition of preservation of "Salamini italiani alla cacciatore PDO" during their shelf-life.

High-performance liquid chromatographic radioenzymatic assay for plasma catecyholamines

International Nuclear Information System (INIS)

Klaniecki, T.S.; Corder, C.N.; McDonald, R.H. Jr.; Feldman, J.A.

1977-01-01

A new assay method for plasma catecholamimes (CA) requiring only 50 μl has been developed, which uses high performance liquid chromatography (HPLC). The norepinephrine (NE), dopamine (D), and epinephrine (E) compounds found in plasma are radioactively o-methylated with S-[methyl- 3 H]-adenosyl-L-methionine ( 3 H-SAM) 3 H-SAM by the reaction of catechol-o-methyl transferase (COMT). The reaction is terminated and a standard mixture of nonradioactive o-methylated analogues of NE, D, and E is added to act as a carrier. Following separation by HPLC, the D,L-normetanephrine (NMN), 3-methoxy-4-hydroxyphenylethyl-amine or 3-methoxytyramine (3-MOT), and metanephrine (MN) radioactive peaks are collected which represent NE, D, and E, respectively. Then MNM and MN are oxidized to vanillin, and 3-MOT is acetylated. The products are subsequently separated by solvent extraction. This is necessary in order to avoid high radioactive blanks and to allow quantitation of the radioactivity by liquid scintillation spectrometry. The mean supine levels of NE, D, and E in normal subjects were respectively 182, 33, and 87 pg/ml of plasma. Similar assays on patients with pheochromocytoma revealed 797, 80, and 470 pg/ml

Thermodynamic study of (heptane + amine) mixtures. III: Excess and partial molar volumes in mixtures with secondary, tertiary, and cyclic amines at 298.15 K

International Nuclear Information System (INIS)

Lepori, Luciano; Gianni, Paolo; Spanedda, Andrea; Matteoli, Enrico

2011-01-01

Graphical abstract: Highlights: → Excess volumes of (sec., tert., or cyclic amines + heptane) mixtures. → Excess volumes are positive for small size amines and decrease as the size increases. → Group contributions to predict the partial molar volumes of amines in heptane. → The void volume is larger for sec. and tert. than for linear amines in heptane. → The void volume is much smaller for cyclic than for linear amines in heptane. - Abstract: Excess molar volumes V E at 298.15 K were determined by means of a vibrating tube densimeter for binary mixtures of {heptane + open chain secondary (diethyl to dibutyl) and tertiary (triethyl to tripentyl) amines} as well as for cyclic imines (C 2 , C 3 , C 4 , C 6 , and C 7 ) and primary cycloalkylamines (C 5 , C 6 , C 7 , and C 12 ). The V E values were found positive for mixtures involving small size amines, with V E decreasing as the size increases. Negative V E 's were found for tributyl- and tripentylamine, heptamethylenimine, and cyclododecylamine. Mixtures of heptane with cycloheptylamine showed an s-shaped curve. Partial molar volumes V 0 of amines at infinite dilution in heptane were obtained from V E and compared with V 0 of hydrocarbons and other classes of organic compounds taken from literature. An additivity scheme, based on the intrinsic volume approach, was applied to estimate group (CH 3 , CH 2 , CH, C, NH 2 , NH, N, OH, O, CO, and COO) contributions to V 0 . These contributions, the effect of cyclization on V 0 , and the limiting slope of the apparent excess molar volumes were discussed in terms of solute-solvent and solute-solute interactions.

Generation of induced pluripotent stem cells (iPSCs) stably expressing CRISPR-based synergistic activation mediator (SAM)

DEFF Research Database (Denmark)

Xiong, Kai; Zhou, Yan; Hyttel, Poul

2016-01-01

Human fibroblasts were engineered to express the CRISPR-based synergistic activation mediator (SAM) complex: dCas9-VP64 and MS2-P65-HSF1. Two induced pluripotent stem cells (iPSCs) clones expressing SAM were established by transducing these fibroblasts with lentivirus expressing OCT4, SOX2, KLF4...... a novel, useful tool to investigate genetic regulation of stem cell proliferation and differentiation through CRISPR-mediated activation of endogenous genes....

New insights into controlling tube-bundle fouling using alternative amines

International Nuclear Information System (INIS)

Turner, C.W.; Klimas, S.J.; Guzonas, D.A.; Frattini, P.L.; Fruzzetti, K.

2002-01-01

A volatile amine is added to the secondary heat-transport system of a nuclear power plant to reduce the rate of corrosion and corrosion product transport in the feedwater and to protect steam generator (SG) crevices and materials exposed to steam condensate. Volatility and base strength of the amine at the SG operating temperature are two important considerations when choosing the optimum amine (or mixture of amines) for corrosion control in the steam cycle. Atomic Energy of Canada Limited (AECL) and Electric Power Research Institute (EPRI) have been collaborating in an extensive investigation of the effectiveness of amines at controlling the rate of tube-bundle fouling under SG operating conditions. Tests have been performed using a radiotracing technique in a high-temperature fouling loop facility at Chalk River Laboratories operated by AECL. This investigation has provided new insights into the role played by the amine in determining the rate of tube-bundle fouling in the SG. These insights are being used by AECL and EPRI to develop criteria for the selection of an amine that has optimum properties for both corrosion control and deposit control in the secondary heat transport system. The investigation has found that the rate of tube-bundle fouling is strongly dependent upon the surface chemistry of the corrosion products. For example, the fouling rates of fully oxidized iron oxides, such as hematite and lepidocrocite, are at least an order of magnitude greater than the fouling rate of magnetite under identical operating conditions. The difference is related to the sign of the surface charge on the corrosion products at temperature. The choice of amine for pH-control also influences the fouling rate. This was originally thought to be a surface-charge effect as well, but recent tests have suggested that it is related to the role that the amine plays in governing the rate of deposit consolidation on the heat-transfer surface. Amines that promote a high rate of

Integration, Validation, and Application of a PV Snow Coverage Model in SAM

Energy Technology Data Exchange (ETDEWEB)

Freeman, Janine M. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Ryberg, David Severin [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2017-08-01

Due to the increasing deployment of PV systems in snowy climates, there is significant interest in a method capable of estimating PV losses resulting from snow coverage that has been verified for a variety of system designs and locations. Many independent snow coverage models have been developed over the last 15 years; however, there has been very little effort verifying these models beyond the system designs and locations on which they were based. Moreover, major PV modeling software products have not yet incorporated any of these models into their workflows. In response to this deficiency, we have integrated the methodology of the snow model developed in the paper by Marion et al. (2013) into the National Renewable Energy Laboratory's (NREL) System Advisor Model (SAM). In this work, we describe how the snow model is implemented in SAM and we discuss our demonstration of the model's effectiveness at reducing error in annual estimations for three PV arrays. Next, we use this new functionality in conjunction with a long term historical data set to estimate average snow losses across the United States for two typical PV system designs. The open availability of the snow loss estimation capability in SAM to the PV modeling community, coupled with our results of the nationwide study, will better equip the industry to accurately estimate PV energy production in areas affected by snowfall.

Production of Primary Amines by Reductive Amination of Biomass-Derived Aldehydes/Ketones.

Science.gov (United States)

Liang, Guanfeng; Wang, Aiqin; Li, Lin; Xu, Gang; Yan, Ning; Zhang, Tao

2017-03-06

Transformation of biomass into valuable nitrogen-containing compounds is highly desired, yet limited success has been achieved. Here we report an efficient catalyst system, partially reduced Ru/ZrO 2 , which could catalyze the reductive amination of a variety of biomass-derived aldehydes/ketones in aqueous ammonia. With this approach, a spectrum of renewable primary amines was produced in good to excellent yields. Moreover, we have demonstrated a two-step approach for production of ethanolamine, a large-market nitrogen-containing chemical, from lignocellulose in an overall yield of 10 %. Extensive characterizations showed that Ru/ZrO 2 -containing multivalence Ru association species worked as a bifunctional catalyst, with RuO 2 as acidic promoter to facilitate the activation of carbonyl groups and Ru as active sites for the subsequent imine hydrogenation. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Extraction separation studies of uranium(VI) by amine oxides

International Nuclear Information System (INIS)

Ejaz, M.

1975-01-01

The extraction of uranium(VI) by two amine oxides, 4-(5-nonyl)pyridine oxide and trioctylamine oxide has been studied. The extraction behavior of these two N-oxides is compared. The dependence of extraction on the type of amine oxide and acid, nature of organic diluent, and amine oxide concentration has been investigated. The influence of the concentration of the metal and salting-out agents is described. The possible mechanism of extraction is discussed in the light of the results of extraction isotherms, loading radiodata, and log-log plots of amine oxide concentration vs distribution ratio. The separation factors for a number of metal ions are reported, and the separation of uranium from some fission elements has also been achieved

Niedualna uważność a stan samādhi w kontekście badań neurofenomenologicznych

Directory of Open Access Journals (Sweden)

Piotr PŁANETA

2016-12-01

Full Text Available The aim of this paper is to compare various meditative states, such as Buddhist dhyāna‑s, yogic nirbīja samādhi and nondual awareness (Tib. gñis‑med. The primary source texts I refere to are Yogasūtras of Patañjali, Ānāpānasmṛtisūtra (MN 118, Samādhisūtra (AN 4.41, The Tibetan Yogas of Dream and Sleep. I also discuss some relevant claims of contemporary empirical studies. First, I define the key terms used in Eastern meditation studies as well as in neurophenomenology, a contemporary method applied to examining the meditative states of mind, such as samādhi, dhyāna, and śamatha. Inspired by Shinzen Young, I distinguish three groups of meditative states that might be identified with nondual awareness. These three groups are: (1 the second, the third and fourth Buddhist dhyāna being equivalent to nirvicāra samādhi and nirānanda samādhi in the classical Indian yoga; (2 nirbīja samādhi and (3 nondual awareness, typical to the Mahayāna contemplative traditions. I explain why we can recognize each of the above states as nondual awareness and how they differ from each other. Then, I make a comparison between meditation practice explained in Ānāpānasmṛtisūtra and nondual awareness presented in the Tibetan Buddhism. Besides, I discuss the above kinds of mental states in terms of recent neurophenomenological findings. While doing so, I am trying to demonstrate that our understanding of meditation can benefit from the empirical studies which help us to objectify this kind of subjective experience, to some degree, if they are given an adequate place in our study.

Effect of donor orientation on ultrafast intermolecular electron transfer in coumarin-amine systems

International Nuclear Information System (INIS)

Singh, P. K.; Nath, S.; Bhasikuttan, A. C.; Kumbhakar, M.; Mohanty, J.; Sarkar, S. K.; Mukherjee, T.; Pal, H.

2008-01-01

Effect of donor amine orientation on nondiffusive ultrafast intermolecular electron transfer (ET) reactions in coumarin-amine systems has been investigated using femtosecond fluorescence upconversion measurements. Intermolecular ET from different aromatic and aliphatic amines used as donor solvents to the excited coumarin-151 (C151) acceptor occurs with ultrafast rates such that the shortest fluorescence lifetime component (τ 1 ) is the measure of the fastest ET rate (τ 1 =τ ET fast =(k ET fast ) -1 ), assigned to the C151-amine contact pairs in which amine donors are properly oriented with respect to C151 to maximize the acceptor-donor electronic coupling (V el ). It is interestingly observed that as the amine solvents are diluted by suitable diluents (either keeping solvent dielectric constant similar or with increasing dielectric constant), the τ 1 remains almost in the similar range as long as the amine dilution does not cross a certain critical limit, which in terms of the amine mole fraction (x A ) is found to be ∼0.4 for aromatic amines and ∼0.8 for aliphatic amines. Beyond these dilutions in the two respective cases of the amine systems, the τ 1 values are seen to increase very sharply. The large difference in the critical x A values involving aromatic and aliphatic amine donors has been rationalized in terms of the largely different orientational restrictions for the ET reactions as imposed by the aliphatic (n-type) and aromatic (π-type) nature of the amine donors [A. K. Satpati et al., J. Mol. Struct. 878, 84 (2008)]. Since the highest occupied molecular orbital (HOMO) of the n-type aliphatic amines is mostly centralized at the amino nitrogen, only some specific orientations of these amines with respect to the close-contact acceptor dye [also of π-character; A. K. Satpati et al., J. Mol. Struct. 878, 84 (2008) and E. W. Castner et al., J. Phys. Chem. A 104, 2869 (2000)] can give suitable V el and thus ultrafast ET reaction. In contrary, the

SAMMate: a GUI tool for processing short read alignments in SAM/BAM format

Directory of Open Access Journals (Sweden)

Flemington Erik

2011-01-01

Full Text Available Abstract Background Next Generation Sequencing (NGS technology generates tens of millions of short reads for each DNA/RNA sample. A key step in NGS data analysis is the short read alignment of the generated sequences to a reference genome. Although storing alignment information in the Sequence Alignment/Map (SAM or Binary SAM (BAM format is now standard, biomedical researchers still have difficulty accessing this information. Results We have developed a Graphical User Interface (GUI software tool named SAMMate. SAMMate allows biomedical researchers to quickly process SAM/BAM files and is compatible with both single-end and paired-end sequencing technologies. SAMMate also automates some standard procedures in DNA-seq and RNA-seq data analysis. Using either standard or customized annotation files, SAMMate allows users to accurately calculate the short read coverage of genomic intervals. In particular, for RNA-seq data SAMMate can accurately calculate the gene expression abundance scores for customized genomic intervals using short reads originating from both exons and exon-exon junctions. Furthermore, SAMMate can quickly calculate a whole-genome signal map at base-wise resolution allowing researchers to solve an array of bioinformatics problems. Finally, SAMMate can export both a wiggle file for alignment visualization in the UCSC genome browser and an alignment statistics report. The biological impact of these features is demonstrated via several case studies that predict miRNA targets using short read alignment information files. Conclusions With just a few mouse clicks, SAMMate will provide biomedical researchers easy access to important alignment information stored in SAM/BAM files. Our software is constantly updated and will greatly facilitate the downstream analysis of NGS data. Both the source code and the GUI executable are freely available under the GNU General Public License at http://sammate.sourceforge.net.

Nitrile-functionalized tertiary amines as highly efficient and reversible SO2 absorbents.

Science.gov (United States)

Hong, Sung Yun; Kim, Heehwan; Kim, Young Jin; Jeong, Junkyo; Cheong, Minserk; Lee, Hyunjoo; Kim, Hoon Sik; Lee, Je Seung

2014-01-15

Three different types of nitrile-functionalized amines, including 3-(N,N-diethylamino)propionitrile (DEAPN), 3-(N,N-dibutylamino)propionitrile (DBAPN), and N-methyl-N,N-dipropionitrile amine (MADPN) were synthesized, and their SO2 absorption performances were evaluated and compared with those of hydroxy-functionalized amines such as N,N-diethyl-N-ethanol amine (DEEA), N,N-dibutyl-N-ethanol amine (DBEA), and N-methyl-N,N-diethanol amine (MDEA). Absorption-desorption cycle experiments clearly demonstrate that the nitrile-functionalized amines are more efficient than the hydroxy-functionalized amines in terms of absorption rate and regenerability. Computational calculations with DBEA and DBAPN revealed that DBEA bearing a hydroxyethyl group chemically interacts with SO2 through oxygen atom, forming an ionic compound with a covalently bound OSO2(-) group. On the contrary, DBAPN bearing a nitrile group physically interacts with SO2 through the nitrogen and the hydrogen atoms of the two methylene groups adjacent to the amino and nitrile functionalities. Copyright © 2013 Elsevier B.V. All rights reserved.

Metal-Mediated Couplings of Primary Alcohols with Amines and Carbohydrates

DEFF Research Database (Denmark)

Maggi, Agnese; Madsen, Robert

. The reaction is proposed to proceed by initial dehydrogenation of the alcohol to the aldehyde, which stays coordinated to the ruthenium centre. Then, nucleophilic attack of the amine affords the hemiaminal, which is released from ruthenium and converted into the imine. Project 2: Tin-mediated regioselective 6...... from alcohols and amines catalyzed by a ruthenium N-heterocyclic carbene complex. The successful method development and application of a convenient and direct (one step) synthesis of imines from alcohols and amines is described. The developed method provides quick andextended access to structurally...... and amines have been coupled in the presence of the catalyst to afford the corresponding imines in moderate to good yields. Optically pure amines gave the corresponding imines without any sign of racemization. Moreover, the one-pot diastereoselective addition of different organometallic reagents to the imine...

Chromosomal localization of the human vesicular amine transporter genes

Energy Technology Data Exchange (ETDEWEB)

Peter, D.; Finn, P.; Liu, Y.; Roghani, A.; Edwards, R.H.; Klisak, I.; Kojis, T.; Heinzmann, C.; Sparkes, R.S. (UCLA School of Medicine, Los Angeles, CA (United States))

1993-12-01

The physiologic and behavioral effects of pharmacologic agents that interfere with the transport of monoamine neurotransmitters into vesicles suggest that vesicular amine transport may contribute to human neuropsychiatric disease. To determine whether an alteration in the genes that encode vesicular amine transport contributes to the inherited component of these disorders, the authors have isolated a human cDNA for the brain transporter and localized the human vesciular amine transporter genes. The human brain synaptic vesicle amine transporter (SVAT) shows unexpected conservation with rat SVAT in the regions that diverge extensively between rat SVAT and the rat adrenal chromaffin granule amine transporter (CGAT). Using the cloned sequences with a panel of mouse-human hybrids and in situ hybridization for regional localization, the adrenal CGAT gene (or VAT1) maps to human chromosome 8p21.3 and the brain SVAT gene (or VAT2) maps to chromosome 10q25. Both of these sites occur very close to if not within previously described deletions that produce severe but viable phenotypes. 26 refs., 3 figs., 1 tab.

Chemical resistivity of self-assembled monolayer covalently attached to silicon substrate to hydrofluoric acid and ammonium fluoride

Science.gov (United States)

Saito, N.; Youda, S.; Hayashi, K.; Sugimura, H.; Takai, O.

2003-06-01

Self-assembled monolayers (SAMs) were prepared on hydrogen-terminated silicon substrates through chemical vapor deposition using 1-hexadecene (HD) as a precursor. The HD-SAMs prepared in an atmosphere under a reduced pressure (≈50 Pa) showed better chemical resistivities to hydrofluoric acid and ammonium fluoride (NH 4F) solutions than that of an organosilane SAM formed on oxide-covered silicon substrates. The surface covered with the HD-SAM was micro-patterned by vacuum ultraviolet photolithography and consequently divided into two areas terminated with HD-SAM or silicon dioxide. This micro-patterned sample was immersed in a 40 vol.% NH 4F aqueous solution. Surface images obtained by an optical microscopy clearly show that the micro-patterns of HD-SAM/silicon dioxide were successfully transferred into the silicon substrate.

Atmospheric modeling of Mars CH4 subsurface clathrates releases mimicking SAM and 2003 Earth-based detections

Science.gov (United States)

Pla-García, J.; Rafkin, S. C.

2017-12-01

The aim of this work is to establish the amount of mixing during all martian seasons to test whether CH4 releases inside or outside of Gale crater are consistent with MSL-SAM observations. Several modeling scenarios were configured, including instantaneous and steady releases, both inside and outside the crater. A simulation to mimic the 2003 Earth-based detections (Mumma et al. 2009 or M09) was also performed. In the instantaneous release inside Gale experiments, Ls270 was shown to be the faster mixing season when air within and outside the crater was well mixed: all tracer mass inside the crater is diluted after just 8 hours. The mixing of near surface crater air with the external environment in the rest of the year is potentially rapid but slower than Ls270.In the instantaneous release outside Gale (NW) experiment, in just 12 hours the CH4 that makes it to the MSL landing location is diluted by six orders of magnitude. The timescale of mixing in MRAMS experiments is on the order of 1 sol regardless of season. The duration of the CH4 peak observed by SAM is 100 sols. Therefore there is a steady release inside the crater, or there is a very large magnitude steady release outside the crater. In the steady release Gale experiments, CH4 flux rate from ground is 1.8 kg m-2 s-1 (derived from Gloesener et al. 2017 clathrates fluxes) and it is not predictive. In these experiments, 200 times lower CH4 values detected by SAM are modeled around MSL location. There are CH4 concentration variations of orders of magnitude depending on the hour, so timing of SAM measurements is important. With a larger (but further away) outside crater release area compared to inside, similar CH4 values around MSL are modeled, so distance to source is important. In the steady experiments mimicking M09 detection release area, only 12 times lower CH4 values detected by SAM are modeled around MSL. The highest value in the M09 modeled scenario (0.6 ppbv) is reached in Ls270. This value is the

Ozone Promotes Chloropicrin Formation by Oxidizing Amines to Nitro Compounds.

Science.gov (United States)

McCurry, Daniel L; Quay, Amanda N; Mitch, William A

2016-02-02

Chloropicrin formation has been associated with ozonation followed by chlorination, but the reaction pathway and precursors have been poorly characterized. Experiments with methylamine demonstrated that ozonation converts methylamine to nitromethane at ∼100% yield. Subsequent chlorination converts nitromethane to chloropicrin at ∼50% yield under the conditions evaluated. Similarly high yields from other primary amines were limited to those with functional groups on the β-carbon (e.g., the carboxylic acid in glycine) that facilitate carbon-carbon bond cleavage to release nitromethyl anion. Secondary amines featuring these reactive primary amines as functional groups (e.g., secondary N-methylamines) formed chloropicrin at high yields, likely by facile dealkylation to release the primary nitro compound. Chloropicrin yields from tertiary amines were low. Natural water experiments, including derivatization to transform primary and secondary amines to less reactive carbamate functional groups, indicated that primary and secondary amines were the dominant chloropicrin precursors during ozonation/chlorination. Ozonation followed by chlorination of the primary amine side chain of lysine demonstrated low yields (∼0.2%) of chloropicrin, but high yields (∼17%) of dichloronitrolysine, a halonitroalkane structural analogue to chloropicrin. However, chloropicrin yields increased and dichloronitrolysine yields decreased in the absence of hydroxyl radical scavengers, suggesting that future research should characterize the potential occurrence of such halonitroalkane analogues relative to natural radical scavenger (e.g., carbonate) concentrations.

Characterization of particulate amines

International Nuclear Information System (INIS)

Gundel, L.A.; Chang, S.G.; Clemenson, M.S.; Markowitz, S.S.; Novakov, T.

1979-01-01

The reduced nitrogen compounds associated with ambient particulate matter are chemically characterized by means of ESCA and proton activation analysis. Ambient particulate samples collected on silver filters in Berkeley, California were washed with water and organic solvents, and ESCA and proton activation analysis were performed in order to determine the composition of various nitrogen compounds and the total nitrogen content. It is found that 85% of the amines originally present in ambient particulate matter can be removed by water extraction, whereas the ammonium and nitrate are completely removed. An observed increase in ammonium ion in the extract, compared with its concentration in the original sample, coupled with the commensurate decrease in amine concentration, is attributed to the hydrolysis of amide groups, which may cause analytical methods based on extraction to yield erroneous results

The Au-S bond and SAM-protein contact in long-range electron transfer of pure and biomimetic metalloproteins via functionalized alkanethiol linkers

DEFF Research Database (Denmark)

Chi, Qijin; Ford, Michael J.; Halder, Arnab

disentangled a wealth of data to identify the nature of the crucial Au-S contact, all suggesting prevalence of a Au(0)-thiyl radical unit. Molecular packing is further determined by the SAM molecular structure and involves binding either to Au-atoms mined out of the surface or directly to a flat surface. We...... functionalized alkanethiols have emerged as core linkers. We have studied molecular linking in the long-range ET (LRET) processes in detail using electrochemistry, in situ STM and AFM, and electronic structure computations. A focus is the electronic structure of the Au-S link and the SAM packing. We have...... is exceedingly sensitive to the structure of the thiol-based SAM molecules, testifying to the crucial importance of SAM packing and Au-S binding, and of the SAM link to the protein. Some of the subtleties are illustrated simpler by similar size (5-6 nm) nanoparticles (NPs). Biomimetic NPs must possess a certain...

REPRESENTASI HOMOSEKSUALITAS DI YOUTUBE: (Studi Semiotika pada Video Pernikahan Sam Tsui

Directory of Open Access Journals (Sweden)

Lilis Rucirisyanti

2017-12-01

Full Text Available Abstract. Social media is instrumental in giving effect to nitizens, good effects or bad effect, then social media can be also represent a person. Diserve social media make it interesting for nitizens. One of social media is Youtube. Many a lot of video at there, strat from tips and trick videos, journey or vacation video, wedding video, and ect. Everyone can publish their video on Youtube. No exception of same sex enthusiast, in this study are homosexual or gay. One of is a wedding video Sam Tsui and Casey Braves. This research is a qualitative research and this research uses semiotcs analysus of Roland Barthes. By doing an analysis of video that have been published by Sam on Youtube, also do document search and literature. The author sees the existence of verbal and non vebal forms of representation from same sex merriage video of men and men.

Application of the SAM Computer Program for Truckee River Stable Channel Analysis

National Research Council Canada - National Science Library

Scott, Stephen H

2006-01-01

The purpose of this Coastal and Hydraulics Engineering Technical Note (CHETN) is to demonstrate the utility of the SAM computer programs for evaluating the stability of a stream restoration design on the Truckee River...

Parabolic Trough Reference Plant for Cost Modeling with the Solar Advisor Model (SAM)

Energy Technology Data Exchange (ETDEWEB)

Turchi, C.

2010-07-01

This report describes a component-based cost model developed for parabolic trough solar power plants. The cost model was developed by the National Renewable Energy Laboratory (NREL), assisted by WorleyParsons Group Inc., for use with NREL's Solar Advisor Model (SAM). This report includes an overview and explanation of the model, two summary contract reports from WorleyParsons, and an Excel spreadsheet for use with SAM. The cost study uses a reference plant with a 100-MWe capacity and six hours of thermal energy storage. Wet-cooling and dry-cooling configurations are considered. The spreadsheet includes capital and operating cost by component to allow users to estimate the impact of changes in component costs.

The Seismic Aftershock Monitoring System (SAMS) for OSI - Experiences from IFE14

Science.gov (United States)

Gestermann, Nicolai; Sick, Benjamin; Häge, Martin; Blake, Thomas; Labak, Peter; Joswig, Manfred

2016-04-01

An on-site inspection (OSI) is the third of four elements of the verification regime of the Comprehensive Nuclear-Test-Ban Treaty (CTBT). The sole purpose of an OSI is to confirm whether a nuclear weapon test explosion or any other nuclear explosion has been carried out in violation of the treaty and to gather any facts which might assist in identifying any possible violator. It thus constitutes the final verification measure under the CTBT if all other available measures are not able to confirm the nature of a suspicious event. The Provisional Technical Secretariat (PTS) carried out the Integrated Field Exercise 2014 (IFE14) in the Dead Sea Area of Jordan from 3 November to 9. December 2014. It was a fictitious OSI whose aim was to test the inspection capabilities in an integrated manner. The technologies allowed during an OSI are listed in the Treaty. The aim of the Seismic Aftershock Monitoring System (SAMS) is to detect and localize aftershocks of low magnitudes of the triggering event or collapses of underground cavities. The locations of these events are expected in the vicinity of a possible previous explosion and help to narrow down the search area within an inspection area (IA) of an OSI. The success of SAMS depends on the main elements, hardware, software, deployment strategy, the search logic and not least the effective use of personnel. All elements of SAMS were tested and improved during the Built-Up Exercises (BUE) which took place in Austria and Hungary. IFE14 provided more realistic climatic and hazardous terrain conditions with limited resources. Significant variations in topography of the IA of IFE14 in the mountainous Dead Sea Area of Jordan led to considerable challenges which were not expected from experiences encountered during BUE. The SAMS uses mini arrays with an aperture of about 100 meters and with a total of 4 elements. The station network deployed during IFE14 and results of the data analysis will be presented. Possible aftershocks of

The ozonolysis of primary aliphatic amines in fine particles

Science.gov (United States)

Zahardis, J.; Geddes, S.; Petrucci, G. A.

2008-02-01

The oxidative processing by ozone of the particulate amines octadecylamine (ODA) and hexadecylamine (HDA) is reported. Ozonolysis of these amines resulted in strong NO2- and NO3- ion signals that increased with ozone exposure as monitored by photoelectron resonance capture ionization aerosol mass spectrometry. These products suggest a mechanism of progressive oxidation of the particulate amines to nitroalkanes. Additionally, a strong ion signal at 125 m/z is assigned to the ion NO3- (HNO3). For ozonized mixed particles containing ODA or HDA + oleic acid (OL), with pO3≥3×10-7 atm, imine, secondary amide, and tertiary amide products were measured. These products most likely arise from reactions of amines with aldehydes (for imines) and stabilized Criegee intermediates (SCI) or secondary ozonides (for amides) from the fatty acid. The routes to amides via SCI and/or secondary ozonides were shown to be more important than comparable amide forming reactions between amines and organic acids, using azelaic acid as a test compound. Finally, direct evidence is provided for the formation of a surface barrier in the ODA + OL reaction system that resulted in the retention of OL at high ozone exposures (up to 10-3 atm for 17 s). This effect was not observed in HDA + OL or single component OL particles, suggesting that it may be a species-specific surfactant effect from an in situ generated amide or imine. Implications to tropospheric chemistry, including particle bound amines as sources of oxidized gas phase nitrogen species (e.g.~NO2, NO3), formation of nitrogen enriched HULIS via ozonolysis of amines and source apportionment are discussed.

Amine-selective bioconjugation using arene diazonium salts.

Science.gov (United States)

Diethelm, Stefan; Schafroth, Michael A; Carreira, Erick M

2014-08-01

A novel bioconjugation strategy is presented that relies on the coupling of diazonium terephthalates with amines in proteins. The diazonium captures the amine while the vicinal ester locks it through cyclization, ensuring no reversibility. The reaction is highly efficient and proceeds under mild conditions and short reaction times. Densely functionalized, complex natural products were directly coupled to proteins using low concentrations of coupling partners.

Must, valge + hall : Sam Wagstaffi ja Robert Mapplethorpe'i portree / Madis Palm

Index Scriptorium Estoniae

Palm, Madis

2008-01-01

Dokumentaalfilm "Black, White & Gray: Sam Wagstaff and Robert Mapplethorpe" : autor ja režissöör James Crump : Ameerika Ühendriigid 2007. Filmi näidati filminädala "Art in America" raames Tallinnas

STUDIES ON VINYL POLYMERIZATION WITH INITIATION SYSTEM CONTAINING AMINE DERIVATIVES

Institute of Scientific and Technical Information of China (English)

QIU Kunyuan; ZHANG Jingyi; FENG Xinde(S. T. Voong)

1983-01-01

Two main types of amine-containing initiation systems were studied in this work. In the case of MMA polymerization initiated by BPO-amine (DMT, DHET, DMA) redox systems, it was found that the polymerization rate and colour stability of the polymer for different amine systems were in the following order: DMT≈DHET＞DMA. Accordingly, BPO-DMT and BPO-DHET are effective initiators. In the case of MEMA polymerization by amine (DMT, DHET, DMA) alone, it was found that the polymerization rate and the percentage of conversion for these different amine systems were in the following order: DMT≥DHET＞DMA. The polymerization rate and the percentage of conversion also increased with the increase of DMT concentration. From the kinetic investigation the rate equation of Rp=K [DMT]1/2 [MEMA]3/2 was obtained, and the overall activation energy of polymerization was calculated to be 34.3 KJ/mol (8.2 Kcal/mol). Moreover, the polymerization of MEMA in the presence of DMT was strongly inhibited by hydroquinone, indicating the polymerization being free radical in nature. From these results, the mechanism of MEMA polymerization initiated by amine was proposed.

Redox self-sufficient whole cell biotransformation for amination of alcohols.

Science.gov (United States)

Klatte, Stephanie; Wendisch, Volker F

2014-10-15

Whole cell biotransformation is an upcoming tool to replace common chemical routes for functionalization and modification of desired molecules. In the approach presented here the production of various non-natural (di)amines was realized using the designed whole cell biocatalyst Escherichia coli W3110/pTrc99A-ald-adh-ta with plasmid-borne overexpression of genes for an l-alanine dehydrogenase, an alcohol dehydrogenase and a transaminase. Cascading alcohol oxidation with l-alanine dependent transamination and l-alanine dehydrogenase allowed for redox self-sufficient conversion of alcohols to the corresponding amines. The supplementation of the corresponding (di)alcohol precursors as well as amino group donor l-alanine and ammonium chloride were sufficient for amination and redox cofactor recycling in a resting buffer system. The addition of the transaminase cofactor pyridoxal-phosphate and the alcohol dehydrogenase cofactor NAD(+) was not necessary to obtain complete conversion. Secondary and cyclic alcohols, for example, 2-hexanol and cyclohexanol were not aminated. However, efficient redox self-sufficient amination of aliphatic and aromatic (di)alcohols in vivo was achieved with 1-hexanol, 1,10-decanediol and benzylalcohol being aminated best. Copyright © 2014 Elsevier Ltd. All rights reserved.

Base metal dehydrogenation of amine-boranes

Science.gov (United States)

Blacquiere, Johanna Marie [Ottawa, CA; Keaton, Richard Jeffrey [Pearland, TX; Baker, Ralph Thomas [Los Alamos, NM

2009-06-09

A method of dehydrogenating an amine-borane having the formula R.sup.1H.sub.2N--BH.sub.2R.sup.2 using base metal catalyst. The method generates hydrogen and produces at least one of a [R.sup.1HN--BHR.sup.2].sub.m oligomer and a [R.sup.1N--BR.sup.2].sub.n oligomer. The method of dehydrogenating amine-boranes may be used to generate H.sub.2 for portable power sources, such as, but not limited to, fuel cells.

Systems of cerium(3) nitrate-dimethyl amine nitrate-water and cerium(3) nitrate-dimethyl amine nitrate-water

International Nuclear Information System (INIS)

Mininkov, N.E.; Zhuravlev, E.F.

1976-01-01

Solubility of solid phases in the systems cerium(3)nitrate-water-dimethyl amine nitrate and cerium(3)nitrate-water-dimethyl amine nitrate has been st ed by the method of isothermal sections at 25 and 50 deo. C. It has been shown that one anhydrous compound is formed in each system with a ratio of cerium(3) nitrate to amine nitrate 1:5. The compounds formed in the systems have been separated from the corresponding solutions and studied by microcrystalloscopic, X-ray phase, thermal and infrared spectroscopic methods. On the basis of spectroscopic studies the following formula has been assigned to the compound: [(CH 3 ) 2 NH 2 + ] 5 x[Ce(NO 3 ) 8 ]. The thermal analysis of the compound has shown that its melting point is 106 deg C. The solubility isotherms in the system Ce(NO 3 ) 3 -H 2 O-(C 2 H 5 ) 2 NHxHNO 3 consist of three branches which intersect in two eutonic points

Extraction of some acids using aliphatic amines

International Nuclear Information System (INIS)

Matutano, L.

1964-06-01

Hydrochloric, nitric, sulphuric, perchloric, phosphoric, acetic and formic acids in aqueous solution (0.05 to 10 M) are extracted by amberlite LA2 and trilaurylamine in solution, 5 per cent by volume, in kerosene and xylene respectively. The extraction process consists of: neutralization of the amine salt; a 'molecular extraction', i.e. an extraction using an excess of acid with respect to the stoichiometry of the amine salt. According to the behaviour of the acid during the extraction, three groups may be distinguished: completely dissociated acids, carboxylic acids, phosphoric acid. This classification is also valid for the extraction of the water which occurs simultaneously with that of the acid. An extraction mechanism is put forward for formic acid and the formation constant of its amine salt is calculated. (author) [fr

40 CFR 721.3620 - Fatty acid amine condensate, polycarboxylic acid salts.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Fatty acid amine condensate... Specific Chemical Substances § 721.3620 Fatty acid amine condensate, polycarboxylic acid salts. (a... a fatty acid amine condensate, polycarboxylic acid salts. (PMN P-92-445) is subject to reporting...

Boron-Catalyzed N-Alkylation of Amines using Carboxylic Acids.

Science.gov (United States)

Fu, Ming-Chen; Shang, Rui; Cheng, Wan-Min; Fu, Yao

2015-07-27

A boron-based catalyst was found to catalyze the straightforward alkylation of amines with readily available carboxylic acids in the presence of silane as the reducing agent. Various types of primary and secondary amines can be smoothly alkylated with good selectivity and good functional-group compatibility. This metal-free amine alkylation was successfully applied to the synthesis of three commercial medicinal compounds, Butenafine, Cinacalcet. and Piribedil, in a one-pot manner without using any metal catalysts. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Congressmember Sam Farr: Five Decades of Public Service

OpenAIRE

Reti, Irene H.; Farr, Sam

2017-01-01

Congressmember Sam Farr (born July 4, 1941) represented California’s Central Coast in the United States House of Representatives for twenty-three years until his retirement from office in 2016.  Farr also served six years as a member of the Monterey County Board of Supervisors and twelve years in the California State Assembly. This oral history, a transcript of twenty-five hours of interviews conducted by Irene Reti, director of the UCSC Library’s Regional History Project, during the period i...

Conversion of alcohols to enantiopure amines through dual-enzyme hydrogen-borrowing cascades.

Science.gov (United States)

Mutti, Francesco G; Knaus, Tanja; Scrutton, Nigel S; Breuer, Michael; Turner, Nicholas J

2015-09-25

α-Chiral amines are key intermediates for the synthesis of a plethora of chemical compounds at industrial scale. We present a biocatalytic hydrogen-borrowing amination of primary and secondary alcohols that allows for the efficient and environmentally benign production of enantiopure amines. The method relies on a combination of two enzymes: an alcohol dehydrogenase (from Aromatoleum sp., Lactobacillus sp., or Bacillus sp.) operating in tandem with an amine dehydrogenase (engineered from Bacillus sp.) to aminate a structurally diverse range of aromatic and aliphatic alcohols, yielding up to 96% conversion and 99% enantiomeric excess. Primary alcohols were aminated with high conversion (up to 99%). This redox self-sufficient cascade possesses high atom efficiency, sourcing nitrogen from ammonium and generating water as the sole by-product. Copyright © 2015, American Association for the Advancement of Science.

Detection of cometary amines in samples returned by Stardust

Science.gov (United States)

Glavin, D. P.; Dworkin, J. P.; Sandford, S. A.

2008-02-01

The abundances of amino acids and amines, as well as their enantiomeric compositions, were measured in samples of Stardust comet-exposed aerogel and foil using liquid chromatography with UV fluorescence detection and time of flight mass spectrometry (LC-FD/ToF-MS). A suite of amino acids and amines including glycine, L-alanine, β-alanine (BALA), γ-amino-n-butyric acid (GABA), ɛ-amino-n-caproic acid (EACA), ethanolamine (MEA), methylamine (MA), and ethylamine (EA) were identified in acid-hydrolyzed, hot-water extracts of these Stardust materials above background levels. With the exception of MA and EA, all other primary amines detected in cometexposed aerogel fragments C2054,4 and C2086,1 were also present in the flight aerogel witness tile that was not exposed to the comet, indicating that most amines are terrestrial in origin. The enhanced relative abundances of MA and EA in comet-exposed aerogel compared to controls, coupled with MA to EA ratios (C2054,4: 1.0 ± 0.2; C2086,1: 1.8 ± 0.2) that are distinct from preflight aerogels (E243-13C and E243-13F: 7 ± 3), suggest that these volatile amines were captured from comet Wild 2. MA and EA were present predominantly in an acid-hydrolyzable bound form in the aerogel, rather than as free primary amines, which is consistent with laboratory analyses of cometary ice analog materials. It is possible that Wild 2 MA and EA were formed on energetically processed icy grains containing ammonia and approximately equal abundances of methane and ethane. The presence of cometary amines in Stardust material supports the hypothesis that comets were an important source of prebiotic organic carbon and nitrogen on the early Earth.

The ozonolysis of primary aliphatic amines in fine particles

Directory of Open Access Journals (Sweden)

J. Zahardis

2008-02-01

Full Text Available The oxidative processing by ozone of the particulate amines octadecylamine (ODA and hexadecylamine (HDA is reported. Ozonolysis of these amines resulted in strong NO₂^– and NO₃^– ion signals that increased with ozone exposure as monitored by photoelectron resonance capture ionization aerosol mass spectrometry. These products suggest a mechanism of progressive oxidation of the particulate amines to nitroalkanes. Additionally, a strong ion signal at 125 m/z is assigned to the ion NO₃^– (HNO₃. For ozonized mixed particles containing ODA or HDA + oleic acid (OL, with p_O3≥3×10^–7 atm, imine, secondary amide, and tertiary amide products were measured. These products most likely arise from reactions of amines with aldehydes (for imines and stabilized Criegee intermediates (SCI or secondary ozonides (for amides from the fatty acid. The routes to amides via SCI and/or secondary ozonides were shown to be more important than comparable amide forming reactions between amines and organic acids, using azelaic acid as a test compound. Finally, direct evidence is provided for the formation of a surface barrier in the ODA + OL reaction system that resulted in the retention of OL at high ozone exposures (up to 10⁻³ atm for 17 s. This effect was not observed in HDA + OL or single component OL particles, suggesting that it may be a species-specific surfactant effect from an in situ generated amide or imine. Implications to tropospheric chemistry, including particle bound amines as sources of oxidized gas phase nitrogen species (e.g.~NO₂, NO₃, formation of nitrogen enriched HULIS via ozonolysis of amines and source apportionment are discussed.

Catalyst for hydrogen-amine D exchange

International Nuclear Information System (INIS)

Holtslander, W.J.; Johnson, R.E.

1976-01-01

A process is claimed for deuterium isotopic enrichment (suitable for use in heavy water production) by amine-hydrogen exchange in which the exchange catalyst comprises a mixture of alkyl amides of two metals selected from the group consisting of the alkali metals. Catalyst mixtures comprising at least one of the alkali amides of lithium and potassium are preferred. At least one of the following benefits are obtained: decreased hydride formation, decreased thermal decomposition of alkyl amide, increased catalyst solubility in the amine phase, and increased exchange efficiency. 11 claims

Structure and activity of Aspergillus nidulans copper amine oxidase

DEFF Research Database (Denmark)

McGrath, Aaron P; Mithieux, Suzanne M; Collyer, Charles A

2011-01-01

Aspergillus nidulans amine oxidase (ANAO) has the unusual ability among the family of copper and trihydroxyphenylalanine quinone-containing amine oxidases of being able to oxidize the amine side chains of lysine residues in large peptides and proteins. We show here that in common with the related...... enzyme from the yeast Pichia pastoris, ANAO can promote the cross-linking of tropoelastin and oxidize the lysine residues in α-casein proteins and tropoelastin. The crystal structure of ANAO, the first for a fungal enzyme in this family, has been determined to a resolution of 2.4 Å. The enzyme is a dimer...... with the archetypal fold of a copper-containing amine oxidase. The active site is the most open of any of those of the structurally characterized enzymes in the family and provides a ready explanation for its lysine oxidase-like activity....

Genome sequencing and annotation of Stenotrophomonas sp. SAM8

Directory of Open Access Journals (Sweden)

Samy Selim

2015-12-01

Full Text Available We report draft genome sequence of Stenotrophomonas sp. strain SAM8, isolated from environmental water. The draft genome size is 3,665,538 bp with a G + C content of 67.2% and contains 6 rRNA sequence (single copies of 5S, 16S & 23S rRNA. The genome sequence can be accessed at DDBJ/EMBL/GenBank under the accession no. LDAV00000000.

Technical Manual for the SAM Biomass Power Generation Model

Energy Technology Data Exchange (ETDEWEB)

Jorgenson, J.; Gilman, P.; Dobos, A.

2011-09-01

This technical manual provides context for the implementation of the biomass electric power generation performance model in the National Renewable Energy Laboratory's (NREL's) System Advisor Model (SAM). Additionally, the report details the engineering and scientific principles behind the underlying calculations in the model. The framework established in this manual is designed to give users a complete understanding of behind-the-scenes calculations and the results generated.

Structural basis of RNA recognition and dimerization by the STAR proteins T-STAR and Sam68

Science.gov (United States)

Feracci, Mikael; Foot, Jaelle N.; Grellscheid, Sushma N.; Danilenko, Marina; Stehle, Ralf; Gonchar, Oksana; Kang, Hyun-Seo; Dalgliesh, Caroline; Meyer, N. Helge; Liu, Yilei; Lahat, Albert; Sattler, Michael; Eperon, Ian C.; Elliott, David J.; Dominguez, Cyril

2016-01-01

Sam68 and T-STAR are members of the STAR family of proteins that directly link signal transduction with post-transcriptional gene regulation. Sam68 controls the alternative splicing of many oncogenic proteins. T-STAR is a tissue-specific paralogue that regulates the alternative splicing of neuronal pre-mRNAs. STAR proteins differ from most splicing factors, in that they contain a single RNA-binding domain. Their specificity of RNA recognition is thought to arise from their property to homodimerize, but how dimerization influences their function remains unknown. Here, we establish at atomic resolution how T-STAR and Sam68 bind to RNA, revealing an unexpected mode of dimerization different from other members of the STAR family. We further demonstrate that this unique dimerization interface is crucial for their biological activity in splicing regulation, and suggest that the increased RNA affinity through dimer formation is a crucial parameter enabling these proteins to select their functional targets within the transcriptome. PMID:26758068

Yb(OTf){sub 3}-catalyzed one-pot three component synthesis for tertiary amines

Energy Technology Data Exchange (ETDEWEB)

Lee, Bum Seok; Kim, Ji Hye; Nam, Tae Kyu; Jang, Doo Ok [Dept. of Chemistry, Yonsei University, Wonju (Korea, Republic of)

2015-07-15

Tertiary amine functionality is found in many natural bioactive products such as alkaloids, amino acids, nucleic acids, pharmaceuticals, and agrochemicals. Tertiary amines have also been used as building blocks for nitrogen-containing organic compounds and synthetic polymers. A one-pot method for direct reductive amination of aldehydes has been developed to synthesize tertiary amines using HMDS as a nitrogen source in the presence of Yb(OTf ){sub 3}. With a stoichiometric amount of HMDS, the reaction afforded the desired tertiary amines without competitive reduction of the parent carbonyl compounds. This reaction offers a convenient and efficient protocol for synthesizing aromatic and aliphatic tertiary amines under mild reaction conditions.

Reactions Involving Calcium and Magnesium Sulfates as Potential Sources of Sulfur Dioxide During MSL SAM Evolved Gas Analyses

Science.gov (United States)

McAdam, A. C.; Knudson, C. A.; Sutter, B.; Franz, H. B.; Archer, P. D., Jr.; Eigenbrode, J. L.; Ming, D. W.; Morris, R. V.; Hurowitz, J. A.; Mahaffy, P. R.;

Molecular tilt-dependent and tyrosine-enhanced electron transfer across ITO/SAM/[DPPC–Au NP–Tyrosine] Janus nanoparticle junction

Energy Technology Data Exchange (ETDEWEB)

Sarangi, Nirod Kumar; Patnaik, Archita, E-mail: archita59@yahoo.com [Indian Institute of Technology Madras, Department of Chemistry (India)

2016-09-15

Enhanced interfacial electron transfer (ET) across the otherwise insulating indium tin oxide/alkanethiol self-assembled monolayer (SAM)/redox molecule junction was accomplished when a Janus gold nanoparticle (JNP) protected by bioinspired phosphatidylcholine (DPPC) lipid and tyrosine amino acid ligands was anchored on it. In addition to the most theoretical and experimental investigations on the distance-dependent ET across Metal–Organic SAM–Nanoparticle (NP) architectures, the current results succinctly illustrate molecular tilt angle of the SAM and the characteristic of JNP as key factors in expediting the ET rate via electron tunneling. In the absence of JNP, electron tunneling with a tunneling factor β = 1.1 Å{sup −1} across the SAM was the rate-limiting step, evidenced from electrochemical impedance spectroscopy (EIS). The apparent electron transfer rate constant (k{sub app}{sup 0}) for anchored SAM was enhanced by at least one order of magnitude than the DPPC-only protected nanoparticle, suggesting the potential role of tyrosine towards the enhanced ET. The asymmetric and biogenic nature of the construct sheds light on a potential bioelectronic device for novel electronic attributes.Graphical abstractEntry of TOC .

SEDIMENT-ASSOCIATED REACTIONS OF AROMATIC AMINES. 2. QSAR DEVELOPMENT

Science.gov (United States)

The fate of aromatic amines in soils and sediments is dominated by irreversible binding through nucleophilic addition and oxidative radical coupling. Despite the common occurrence of the aromatic amine functional group in organic chemicals, the molecular properties useful for pr...

Manganese-catalysed benzylic C(sp3)-H amination for late-stage functionalization.

Science.gov (United States)

Clark, Joseph R; Feng, Kaibo; Sookezian, Anasheh; White, M Christina

2018-06-01

Reactions that directly install nitrogen into C-H bonds of complex molecules are significant because of their potential to change the chemical and biological properties of a given compound. Although selective intramolecular C-H amination reactions are known, achieving high levels of reactivity while maintaining excellent site selectivity and functional-group tolerance remains a challenge for intermolecular C-H amination. Here, we report a manganese perchlorophthalocyanine catalyst [MnIII(ClPc)] for intermolecular benzylic C-H amination of bioactive molecules and natural products that proceeds with unprecedented levels of reactivity and site selectivity. In the presence of a Brønsted or Lewis acid, the [MnIII(ClPc)]-catalysed C-H amination demonstrates unique tolerance for tertiary amine, pyridine and benzimidazole functionalities. Mechanistic studies suggest that C-H amination likely proceeds through an electrophilic metallonitrene intermediate via a stepwise pathway where C-H cleavage is the rate-determining step of the reaction. Collectively, these mechanistic features contrast with previous base-metal-catalysed C-H aminations and provide new opportunities for tunable selectivities.

Evidence for Smectite Clays from MSL SAM Analyses of Mudstone at Yellowknife Bay, Gale Crater, Mars

Science.gov (United States)

McAdam, Amy; Franz, Heather; Mahaffy, Paul R.; Eigenbrode, Jennifer L.; Stern, Jennifer C.; Brunner, Anna; Archer, Paul Douglas; Ming, Douglas W.; Morris, Richard V.; Atreya, Sushil K.

2013-01-01

Drilled samples of mudstone from the Sheepbed unit at Yellowknife Bay were analyzed by MSL instruments including the Sample Analysis at Mars (SAM) and Chemistry and Mineralogy (CheMin) instruments in MSL's Analytical Laboratory. CheMin analyses revealed the first in situ X-ray diffraction based evidence of clay minerals on Mars, which are likely trioctahedral smectites (e.g., saponite) and comprise approx 20% of the mudstone sample (e.g., Bristow et al., this meeting). SAM analyses, which heated the mudstone samples to 1000 C and monitored volatiles evolved to perform in situ evolved gas analysis mass spectrometry (EGA-MS), resulted in a H2O trace exhibiting a wide evolution at temperatures smectite interlayer H2O, and structural H2O/OH from bassanite and akaganeite (identified by CheMin) and H2O/OH from amorphous phases in the sample. The high temperature H2O is consistent with the evolution of H2O from the dehydroxylation of the smectite clay mineral. Comparison to EGA-MS data collected under SAM-like conditions on a variety of clay mineral reference materials indicate that a trioctahedral smectite, such as saponite, is most consistent with the high temperature H2O evolution observed. There may also be SAM EGA-MS evidence for a small high temperature H2O evolution from scoop samples from the Yellowknife Bay Rocknest sand shadow bedform. As in the mudstone samples, this evolution may indicate the detection of smectite clays, and the idea that minor clays may be present in Rocknest materials that could be expected to be at least partially derived from local sources is reasonable. But, because smectite clays were not definitively observed in CheMin analyses of Rocknest materials, they must be present at much lower abundances than the approx 20% observed in the mudstone samples. This potential detection underscores the complementary nature of the MSL CheMin and SAM instruments for investigations of martian sample mineralogy. Information on the nature of Yellowknife

Molecular junctions based on SAMs of cruciform oligo(phenylene ethynylene)s

DEFF Research Database (Denmark)

Wei, Zhongming; Li, Tao; Jennum, Karsten Stein

2012-01-01

Cruciform oligo(phenylene ethynylene)s (OPEs) with an extended tetrathiafulvalene (TTF) donor moiety (OPE5-TTF and OPE3-TTF) and their simple analogues (OPE5-S and OPE3) without conjugated substituents were used to form high quality self-assembled monolayers (SAMs) on ultra-flat gold substrates...

Selective translational repression of HIV-1 RNA by Sam68DeltaC occurs by altering PABP1 binding to unspliced viral RNA

Directory of Open Access Journals (Sweden)

Soros Vanessa

2008-10-01

Full Text Available Abstract HIV-1 structural proteins are translated from incompletely spliced 9 kb and 4 kb mRNAs, which are transported to the cytoplasm by Crm1. It has been assumed that once in the cytoplasm, translation of incompletely spliced HIV-1 mRNAs occurs in the same manner as host mRNAs. Previous analyses have demonstrated that Sam68 and a mutant thereof, Sam68ΔC, have dramatic effects on HIV gene expression, strongly enhancing and inhibiting viral structural protein synthesis, respectively. While investigating the inhibition of incompletely spliced HIV-1 mRNAs by Sam68ΔC, we determined that the effect was independent of the perinuclear bundling of the viral RNA. Inhibition was dependent upon the nuclear export pathway used, as translation of viral RNA exported via the Tap/CTE export pathway was not blocked by Sam68ΔC. We demonstrate that inhibition of HIV expression by Sam68ΔC is correlated with a loss of PABP1 binding with no attendant change in polyadenosine tail length of the affected RNAs. The capacity of Sam68ΔC to selectively inhibit translation of HIV-1 RNAs exported by Crm1 suggests that it is able to recognize unique characteristics of these viral RNPs, a property that could lead to new therapeutic approaches to controlling HIV-1 replication.

Astramol polypropyleneimine dendrimers as Norrish Type II amine synergists

NARCIS (Netherlands)

Jansen, J.F.G.A.; Dias, A.A.; Hartwig, H.; Janssen, R.A.J.

2000-01-01

UV-curable coatings for various applications . In most of these applications they serve a dual role ie as initiator and as oxygen scavenger. Dimethylethanolamine is one of the more frequently employed aliphatic amines. However, this amine is a highly volatile . AstramolTM polypropyleneimine

Thermal properties of wood reacted with a phosphorus pentoxide–amine system

Science.gov (United States)

Hong-Lin Lee; George C. Chen; Roger M. Rowell

2004-01-01

The objective of this research was to improve the fire-retardant properties of wood in one treatment using a phosphorus pentoxide–amine system. Phosphorus pentoxide and 16 amines including alkyl, halophenyl, and phenyl amines were compounded in N,N-dimethylformamide and the resulting solutions containing phosphoramides were reacted with wood. The characteristics of...

Bioinspired organocatalytic aerobic C-H oxidation of amines with an ortho-quinone catalyst.

Science.gov (United States)

Qin, Yan; Zhang, Long; Lv, Jian; Luo, Sanzhong; Cheng, Jin-Pei

2015-03-20

A simple bioinspired ortho-quinone catalyst for the aerobic oxidative dehydrogenation of amines to imines is reported. Without any metal cocatalysts, the identified optimal ortho-quinone catalyst enables the oxidations of α-branched primary amines and cyclic secondary amines. Mechanistic studies have disclosed the origins of different performances of ortho-quinone vs para-quinone in biomimetic amine oxidations.

Nitrile-functionalized tertiary amines as highly efficient and reversible SO{sub 2} absorbents

Energy Technology Data Exchange (ETDEWEB)

Hong, Sung Yun; Kim, Heehwan; Kim, Young Jin; Jeong, Junkyo; Cheong, Minserk [Department of Chemistry and Research Institute of Basic Sciences, Kyung Hee University, 1 Hoegi-dong, Dongdaemun-gu, Seoul 130-701 (Korea, Republic of); Lee, Hyunjoo [Clean Energy Center, Korea Institute of Science and Technology, Seoul 136-791 (Korea, Republic of); Kim, Hoon Sik, E-mail: khs2004@khu.ac.kr [Department of Chemistry and Research Institute of Basic Sciences, Kyung Hee University, 1 Hoegi-dong, Dongdaemun-gu, Seoul 130-701 (Korea, Republic of); Lee, Je Seung, E-mail: leejs70@khu.ac.kr [Department of Chemistry and Research Institute of Basic Sciences, Kyung Hee University, 1 Hoegi-dong, Dongdaemun-gu, Seoul 130-701 (Korea, Republic of)

2014-01-15

Highlights: • Nitrile-functionalized tertiary amines physically and reversibly absorb SO{sub 2}. • Tertiary alkanolamines chemically and irreversibly absorb SO{sub 2} through OH group. • SO{sub 2} absorption modes were studied by spectroscopy and computational calculations. -- Abstract: Three different types of nitrile-functionalized amines, including 3-(N,N-diethylamino)propionitrile (DEAPN), 3-(N,N-dibutylamino)propionitrile (DBAPN), and N-methyl-N,N-dipropionitrile amine (MADPN) were synthesized, and their SO{sub 2} absorption performances were evaluated and compared with those of hydroxy-functionalized amines such as N,N-diethyl-N-ethanol amine (DEEA), N,N-dibutyl-N-ethanol amine (DBEA), and N-methyl-N,N-diethanol amine (MDEA). Absorption–desorption cycle experiments clearly demonstrate that the nitrile-functionalized amines are more efficient than the hydroxy-functionalized amines in terms of absorption rate and regenerability. Computational calculations with DBEA and DBAPN revealed that DBEA bearing a hydroxyethyl group chemically interacts with SO{sub 2} through oxygen atom, forming an ionic compound with a covalently bound -OSO{sub 2}{sup −} group. On the contrary, DBAPN bearing a nitrile group physically interacts with SO{sub 2} through the nitrogen and the hydrogen atoms of the two methylene groups adjacent to the amino and nitrile functionalities.

Impact of thiol and amine functionalization on photoluminescence properties of ZnO films

International Nuclear Information System (INIS)

Jayalakshmi, G.; Saravanan, K.; Balasubramanian, T.

2013-01-01

In the present study, we have investigated surface functionalization of ZnO films with dodecanethiol (Thiol) and trioctylamine (amine) by X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), contact angle (CA) and photoluminescence (PL) measurements. The chemical bondings of thiol and amine with ZnO have been confirmed via the formation of Zn–S and Zn–N bonds by XPS measurements. AFM measurements on ZnO films before and after surface functionalization with thiol and amine provide evidence for the successful functionalization of thiol and amine on ZnO surfaces without any island formation. The CA measurements on ZnO films before and after surface functionalization with thiol and amine show the hydrophobic nature. PL measurements of thiol and amine functionalized ZnO show enhancements of UV emission and quenching of visible emission. The enhanced UV emissions in thiol and amine functionalized ZnO films suggest that the surface defects such as oxygen vacancies are passivated by thiol and amine functionalization. -- Highlights: ► Surface functionalization is a new approach to reduce surface dependent non-radiative process. ► Oxygen vacancies are passivated on surface functionalization. ► Thiol and amine functionalized ZnO show enhancements of UV emission

Jo Ann Baumgartner and Sam Earnshaw: Organizers and Farmers

OpenAIRE

Rabkin, Sarah

2010-01-01

Jo Ann Baumgartner directs the Wild Farm Alliance, based in Watsonville, California. WFA’s mission, as described on the organization’s website, is “to promote agriculture that helps to protect and restore wild Nature.” Through research, publications, presentations, events, policy work, and consulting, the organization works to “connect food systems with ecosystems.” Sam Earnshaw is Central Coast regional coordinator of the Community Alliance with Family Farmers. Working with CAFF’s f...

Study on synthesis, application and mechanism of benzophenone/amine initiator

International Nuclear Information System (INIS)

Xiong Wei; Liu Jinshui; Wen Yinjun; Wan Qizhong; Zhou Xianyan; Xiao Hanling; Yang Jianwen

1999-01-01

Through Michael addition reaction of trimethylolpropane triacrylate (TMPTA) with diethylamine (DEA), a new kind of tertiary amine derivative was synthesized and its structure was identified by 'H-NMR. When used in combination with benzophenone, this amine presented excellent curing speed and could be a substitute for initiator Darocur R 1173, which is effective but expensive. If so, the cost of UV-curable coatings can descend apparently. The functioning mechanism of benzophenone/amine bimolecular initiator was studied

Reflections on Sam Harris' "Free Will"

Directory of Open Access Journals (Sweden)

Daniel C. Dennett

2017-12-01

Full Text Available In his book Free Will Sam Harris tries to persuade us to abandon the morally pernicious idea of free will. The following contribution articulates and defends a more sophisticated model of free will that is not only consistent with neuroscience and introspection but also grounds a variety of responsibility that justifies both praise and blame, reward and punishment. This begins with the long lasting parting of opinion between compatibilists (who argue that free will can live comfortably with determinism and incompatibilists (who deny this. While Harris dismisses compatibilism as a form of theology, this article aims at showing that Harris has underestimated and misinterpreted compatibilism and at defending a more sophisticated version of compatibilism that is imprevious to Harris’ criticism.

Intolerance to dietary biogenic amines: a review.

Science.gov (United States)

Jansen, Sophia C; van Dusseldorp, Marijke; Bottema, Kathelijne C; Dubois, Anthony E J

2003-09-01

To evaluate the scientific evidence for purported intolerance to dietary biogenic amines. MEDLINE was searched for articles in the English language published between January 1966 and August 2001. The keyword biogenic amin* was combined with hypersens*, allerg*, intoler*, and adverse. Additionally, the keywords histamine, tyramine, and phenylethylamine were combined with headache, migraine, urticaria, oral challenge, and oral provocation. Articles were also selected from references in relevant literature. Only oral challenge studies in susceptible patients were considered. Studies with positive results (ie, studies in which an effect was reported) were only eligible when a randomized, double-blind, placebo-controlled design was used. Eligible positive result studies were further evaluated according to a number of scientific criteria. Studies with negative results (ie, studies in which no effect was reported) were examined for factors in their design or methods that could be responsible for a false-negative outcome. Results of methodologically weak or flawed studies were considered inconclusive. A total of 13 oral challenge studies (5 with positive results and 8 with negative results) were found. Three of them (all with positive results) were considered ineligible. By further evaluation of the 10 eligible studies, 6 were considered inconclusive. The 4 conclusive studies all reported negative results. One conclusive study showed no relation between biogenic amines in red wine and wine intolerance. Two conclusive studies found no effect of tyramine on migraine. One conclusive study demonstrated no relation between the amount of phenylethylamine in chocolate and headache attacks in individuals with headache. The current scientific literature shows no relation between the oral ingestion of biogenic amines and food intolerance reactions. There is therefore no scientific basis for dietary recommendations concerning biogenic amines in such patients.

A Convenient Approach to Synthesizing Peptide C-Terminal N-Alkyl Amides

Science.gov (United States)

Fang, Wei-Jie; Yakovleva, Tatyana; Aldrich, Jane V.

2014-01-01

Peptide C-terminal N-alkyl amides have gained more attention over the past decade due to their biological properties, including improved pharmacokinetic and pharmacodynamic profiles. However, the synthesis of this type of peptide on solid phase by current available methods can be challenging. Here we report a convenient method to synthesize peptide C-terminal N-alkyl amides using the well-known Fukuyama N-alkylation reaction on a standard resin commonly used for the synthesis of peptide C-terminal primary amides, the PAL-PEG-PS (Peptide Amide Linker-polyethylene glycol-polystyrene) resin. The alkylation and oNBS deprotection were conducted under basic conditions and were therefore compatible with this acid labile resin. The alkylation reaction was very efficient on this resin with a number of different alkyl iodides or bromides, and the synthesis of model enkephalin N-alkyl amide analogs using this method gave consistently high yields and purities, demonstrating the applicability of this methodology. The synthesis of N-alkyl amides was more difficult on a Rink amide resin, especially the coupling of the first amino acid to the N-alkyl amine, resulting in lower yields for loading the first amino acid onto the resin. This method can be widely applied in the synthesis of peptide N-alkyl amides. PMID:22252422

Expanding Applications of SERS through Versatile Nanomaterials Engineering (Postprint)

Science.gov (United States)

2017-06-22

which form covalent metal–S bonds), amine, cyanide , and carboxylic acid functional groups; and their adsorption depends on solution pH and ionic...for some SERS sensing appli- cations, such as biosensing in complex biological fluids (where multiple molecules with primary amine and carboxylic acid...bonding interactions.33d,e Furthermore, mixed SAMs can take advantage of multiple types of interactions and build complexity into the surface chemistry

Determination of rate constants of N-alkylation of primary amines by 1H NMR spectroscopy.

Science.gov (United States)

Li, Chenghong

2013-09-05

Macromolecules containing N-diazeniumdiolates of secondary amines are proposed scaffolds for controlled nitrogen oxide (NO) release medical applications. Preparation of these compounds often involves converting primary amine groups to secondary amine groups through N-alkylation. However, N-alkylation results in not only secondary amines but tertiary amines as well. Only N-diazeniumdiolates of secondary amines are suitable for controlled NO release; therefore, the yield of secondary amines is crucial to the total NO load of the carrier. In this paper, (1)H NMR spectroscopy was used to estimate the rate constants for formation of secondary amine (k1) and tertiary amine (k2) for alkylation reagents such as propylene oxide (PO), methyl acrylate (MA), and acrylonitrile (ACN). At room temperature, the ratio of k2/k1 for the three reactions was found to be around 0.50, 0.026, and 0.0072.

Composition of amino acids and bioactive amines in common wines of Brazil

Directory of Open Access Journals (Sweden)

Bruna Carla Agustini

2014-10-01

Full Text Available Since most consumed wines in Brazil are common wines and since their representativeness is not accounted for in scientific research, current study quantifies bioactive amines and their precursors in Brazilian sweet and dry common wines, correlates the formation of amines with physical and chemical parameters and clusters studied areas by their amine and amino acid contents. Forty-seven wine samples varying in type, color and origin were analyzed simultaneously for seventeen amino acids, ammonium ion and five bioactive amines by reversed-phase high performance liquid chromatography and ultraviolet detection after the derivation phase. Physical and chemical analyses comprised titratable acidity, pH, organic acids, sugar and alcohol contents. Sweet wines had lower concentrations of amino acids and bioactive amines. Dry white wines had higher amino acid contents when compared to those in dry red wines. Since multivariate data analysis confirmed similarities between the studied regions, their unity as potential viniculture area was reinforced. Amine levels in Brazilian common wines were reported for the first time and results reinforced the importance of bioactive amines quantification and the use of suitable vinification practices to reduce their formation.

Conditions allowing the formation of biogenic amines in cheese

NARCIS (Netherlands)

Joosten, H.M.L.J.

1988-01-01

A study was undertaken to reveal the conditions that allow the formation of biogenic amines in cheese.

The starters most commonly used in the Dutch cheese industry do not have decarboxylative properties. Only if the milk or curd is contaminated with non-starter bacteria, amine

Methyl group balance in brain and liver: role of choline on increased S-adenosyl methionine (SAM) demand by chronic arsenic exposure.

Science.gov (United States)

Ríos, Rosalva; Santoyo, Martha E; Cruz, Daniela; Delgado, Juan Manuel; Zarazúa, Sergio; Jiménez-Capdeville, María E

2012-11-30

Arsenic toxicity has been related to its interference with one carbon metabolism, where a high demand of S-adenosylmethionine (SAM) for arsenic methylation as well as a failure of its regeneration would compromise the availability of methyl groups for diverse cellular functions. Since exposed animals show disturbances of methylated products such as methylated arginines, myelin and axon membranes, this work investigates whether alterations of SAM, choline and phosphatidylcholine (PC) in the brain of arsenic exposed rats are associated with myelin alterations and myelin basic protein (MBP) immunoreactivity. Also these metabolites, morphologic and biochemical markers of methyl group alterations were analyzed in the liver, the main site of arsenic methylation. In adult, life-long arsenic exposed rats through drinking water (3 ppm), no changes of SAM, choline and PC concentrations where found in the brain, but SAM and PC were severely decreased in liver accompanied by a significant increase of choline. These results suggest that choline plays an important role as methyl donor in arsenic exposure, which could underlie hepatic affections observed when arsenic exposure is combined with other environmental factors. Also, important myelin and nerve fiber alterations, accompanied by a 75% decrease of MBP immunoreactivity were not associated with a SAM deficit in the brain. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Blue Chitin columns for the extraction of heterocyclic amines from urine samples

DEFF Research Database (Denmark)

Bang, J.; Frandsen, Henrik Lauritz; Skog, K.

2004-01-01

During normal cooking of meat, a class of mutagenic/carcinogenic compounds called heterocyclic amines is formed. Heterocyclic amines are rapidly absorbed and metabolised in the human body, and for estimation of the intake of heterocyclic amines, it is useful to determinate their levels in the uri...

Thermal and Evolved Gas Analysis of Calcite Under Reduced Operating Pressures: Implications for the 2011 MSL Sample Analysis at Mars (SAM) Instrument

Science.gov (United States)

Lauer, H. V. Jr.; Ming, D. W.; Sutter, B.; Mahaffy, P. R.

2010-01-01

The Mars Science Laboratory (MSL) is scheduled for launch in 2011. The science objectives for MSL are to assess the past or present biological potential, to characterize the geology, and to investigate other planetary processes that influence habitability at the landing site. The Sample Analysis at Mars (SAM) is a key instrument on the MSL payload that will explore the potential habitability at the landing site [1]. In addition to searching for organic compounds, SAM will have the capability to characterized evolved gases as a function of increasing temperature and provide information on the mineralogy of volatile-bearing phases such as carbonates, sulfates, phyllosilicates, and Fe-oxyhydroxides. The operating conditions in SAM ovens will be maintained at 30 mb pressure with a He carrier gas flowing at 1 sccm. We have previously characterized the thermal and evolved gas behaviors of volatile-bearing species under reduced pressure conditions that simulated operating conditions of the Thermal and Evolved Gas Analyzer (TEGA) that was onboard the 2007 Mars Phoenix Scout Mission [e.g., 2-8]. TEGA ovens operated at 12 mb pressure with a N2 carrier gas flowing at 0.04 sccm. Another key difference between SAM and TEGA is that TEGA was able to perform differential scanning calorimetry whereas SAM only has a pyrolysis oven. The operating conditions for TEGA and SAM have several key parameter differences including operating pressure (12 vs 30 mb), carrier gas (N2 vs. He), and carrier gas flow rate (0.04 vs 1 sccm). The objectives of this study are to characterize the thermal and evolved gas analysis of calcite under SAM operating conditions and then compare it to calcite thermal and evolved gas analysis under TEGA operating conditions.

Analysis of Biogenic Amines by GC/FID and GC/MS

OpenAIRE

Nakovich, Laura

2003-01-01

Low levels of biogenic amines occur naturally, but high levels (FDA sets 50 ppm of histamine in fish as the maximum allowable level) can lead to scombroid poisoning. Amines in general are difficult to analyze by Gas Chromatography (GC) due to their lack of volatility and their interaction with the GC column, often leading to significant tailing and poor reproducibility. Biogenic amines need to be derivatized before both GC and HPLC analyses. The objective of this research was to devel...

Identification of amines in wintertime ambient particulate material using high resolution aerosol mass spectrometry

Science.gov (United States)

Bottenus, Courtney L. H.; Massoli, Paola; Sueper, Donna; Canagaratna, Manjula R.; VanderSchelden, Graham; Jobson, B. Thomas; VanReken, Timothy M.

2018-05-01

Significant amounts of amines were detected in fine particulate matter (PM) during ambient wintertime conditions in Yakima, WA, using a high resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS). Positive matrix factorization (PMF) of the organic aerosol (OA) signal resulted in a six-factor solution that included two previously unreported amine OA factors. The contributions of the amine factors were strongly episodic, but the concentration of the combined amine factors was as high as 10-15 μg m-3 (2-min average) during those episodes. In one occasion, the Amine-II component was 45% of total OA signal. The Amine-I factor was dominated by spectral peaks at m/z 86 (C5H12N+) and m/z 100 (C6H14N+), while the Amine-II factor was dominated by spectral peaks at m/z 58 (C3H8N+ and C2H6N2+) and m/z 72 (C4H10N+ and C3H8N2+). The ions dominating each amine factor showed distinct time traces, suggesting different sources or formation processes. Investigation into the chemistry of the amine factors suggests a correlation with inorganic anions for Amine-I, but no evidence that the Amine-II was being neutralized by the same inorganic ions. We also excluded the presence of organonitrates (ON) in the OA. The presence of C2H4O2+ at m/z 60 (a levoglucosan fragment) in the Amine-I spectrum suggests some influence of biomass burning emissions (more specifically residential wood combustion) in this PMF factor, but wind direction suggested that the most likely sources of these amines were agricultural activities and feedlots to the S-SW of the site.

iSAM: An iPhone Stealth Airborne Malware

OpenAIRE

Damopoulos , Dimitrios; Kambourakis , Georgios; Gritzalis , Stefanos

2011-01-01

Part 2: Malware, Information Flow and DoS Attacks; International audience; Modern and powerful mobile devices comprise an attractive target for any potential intruder or malicious code. The usual goal of an attack is to acquire users’ sensitive data or compromise the device so as to use it as a stepping stone (or bot) to unleash a number of attacks to other targets. In this paper, we focus on the popular iPhone device.We create a new stealth and airborne malware namely iSAM able to wirelessly...

Electrochemical degradation of aromatic amines on BDD electrodes

International Nuclear Information System (INIS)

Pacheco, M.J.; Santos, V.; Ciriaco, L.; Lopes, A.

2011-01-01

The electrochemical oxidation of four aromatic amines, with different substituent groups, 3-amino-4-hydroxy-5-nitrobenzenesulfonic acid (A1), 5-amino-2-methoxybenzenesulfonic acid (A2), 2,4-dihydroxyaniline hydrochloride (A3) and benzene-1,4-diamine (A4), was performed using as anode a boron-doped diamond electrode, commercially available at Adamant Technologies. Tests were run at room temperature with model solutions of the different amines, with concentrations of 200 ppm, using as electrolyte 0.035 M Na 2 SO 4 aqueous solutions, in a batch cell with recirculation, at different current densities (200 and 300 A m -2 ). The following analyses were performed with the samples collected during the assays: UV-Vis spectrophotometry, chemical oxygen demand (COD), total organic carbon (TOC), total Kjeldahl nitrogen, ammonia nitrogen, nitrates and HPLC. Results have shown a good electrodegradation of all the amines tested, with COD removals, after 6 h assays, higher than 90% and TOC removals between 60 and 80%. Combustion efficiency (η C ), which measures the tendency to convert organic carbon to CO 2 , was also determined for all the amines, being η CA1 CA2 CA3 CA4 = 0.99.

Control of Biogenic Amines in Fermented Sausages: Role of Starter Cultures

Science.gov (United States)

Latorre-Moratalla, M.L.; Bover-Cid, Sara; Veciana-Nogués, M.T.; Vidal-Carou, M.C.

2012-01-01

Biogenic amines show biological activity and exert undesirable physiological effects when absorbed at high concentrations. Biogenic amines are mainly formed by microbial decarboxylation of amino acids and thus are usually present in a wide range of foods, fermented sausages being one of the major biogenic amine sources. The use of selected starter cultures is one of the best technological measures to control aminogenesis during meat fermentation. Although with variable effectiveness, several works show the ability of some starters to render biogenic amine-free sausages. In this paper, the effect of different starter culture is reviewed and the factors determining their performance discussed. PMID:22586423

Control of biogenic amines in fermented sausages: role of starter cultures

Directory of Open Access Journals (Sweden)

Mariluz eLatorre-Moratalla

2012-05-01

Full Text Available Biogenic amines show biological activity and exert undesirable physiological effects when absorbed at high concentrations. Biogenic amines are mainly formed by microbial decarboxylation of amino acids and thus are usually present in a wide range of foods, fermented sausages being one of the major biogenic amine sources. The use of selected starter cultures is one of the best technological measures to control aminogenesis during meat fermentation. Although with variable effectiveness, several works show the ability of some starters to render biogenic amine-free sausages. In this paper, the effect of different starter culture is reviewed and the factors determining their performance discussed.

Stealing the gold a celebration of the pioneering physics of Sam Edwards

CERN Document Server

Goldenfeld, Nigel; Sherrington, D C; Edwards, S F

2004-01-01

This title presents a survey of some of the most exciting topics in condensed matter physics today, from the perspective of the pioneering work of Sam Edwards. Original articles from leaders in the field highlight the historical development as well as new and emerging areas.

Amine oxidases as important agents of pathological processes of rhabdomyolysis in rats.

Science.gov (United States)

Gudkova, O O; Latyshko, N V; Shandrenko, S G

2016-01-01

In this study we have tested an idea on the important role of amine oxidases (semicarbazide-sensitive amine oxidase, diamine oxidase, polyamine oxidase) as an additional source of oxidative/carbonyl stress under glycerol-induced rhabdomyolysis, since the enhanced formation of reactive oxygen species and reactive carbonyl species in a variety of tissues is linked to various diseases. In our experiments we used the sensitive fluorescent method devised for estimation of amine oxidases activity in the rat kidney and thymus as targeted organs under rhabdomyolysis. We have found in vivo the multiple rises in activity of semicarbazide-sensitive amine oxidase, diamine oxidase, polyamine oxidase (2-4.5 times) in the corresponding cell fractions, whole cells or their lysates at the 3-6th day after glycerol injection. Aberrant antioxidant activities depended on rhabdomyolysis stage and had organ specificity. Additional treatment of animals with metal chelator ‘Unithiol’ adjusted only the activity of antioxidant enzymes but not amine oxidases in both organs. Furthermore the in vitro experiment showed that Fenton reaction (hydrogen peroxide in the presence of iron) products alone had no effect on semicarbazide-sensitive amine oxidase activity in rat liver cell fraction whereas supplementation with methylglyoxal resulted in its significant 2.5-fold enhancement. Combined action of the both agents had additive effect on semicarbazide-sensitive amine oxidase activity. We can assume that biogenic amine and polyamine catabolism by amine oxidases is upregulated by oxidative and carbonyl stress factors directly under rhabdomyolysis progression, and the increase in catabolic products concentration contributes to tissue damage in glycerol-induced acute renal failure and apoptosis stimulation in thymus.

Evolved Gas Analyses of Sedimentary Materials in Gale Crater, Mars: Results of the Curiosity Rover's Sample Analysis at Mars (SAM) Instrument from Yellowknife Bay to the Stimson Formation

Science.gov (United States)

Sutter, B.; McAdam, A. C.; Rampe, E. B.; Ming, D. W.; Mahaffy, P. R.; Navarro-Gonzalez, R.; Stern, J. C.; Eigenbrode, J. L.; Archer, P. D.

2016-01-01

The Sample Analysis at Mars (SAM) instrument aboard the Mars Science Laboratory rover has analyzed 10 samples from Gale Crater. All SAM evolved gas analyses have yielded a multitude of volatiles (e.g, H2O, SO2, H2S, CO2, CO, NO, O2, HC1). The objectives of this work are to 1) Characterize the evolved H2O, SO2, CO2, and O2 gas traces of sediments analyzed by SAM through sol 1178, 2) Constrain sediment mineralogy/composition based on SAM evolved gas analysis (SAM-EGA), and 3) Discuss the implications of these results releative to understanding the geochemical history of Gale Crater.

Radical SAM Enzymes in the Biosynthesis of Ribosomally Synthesized and Post-translationally Modified Peptides (RiPPs

Directory of Open Access Journals (Sweden)

Alhosna Benjdia

2017-11-01

Full Text Available Ribosomally-synthesized and post-translationally modified peptides (RiPPs are a large and diverse family of natural products. They possess interesting biological properties such as antibiotic or anticancer activities, making them attractive for therapeutic applications. In contrast to polyketides and non-ribosomal peptides, RiPPs derive from ribosomal peptides and are post-translationally modified by diverse enzyme families. Among them, the emerging superfamily of radical SAM enzymes has been shown to play a major role. These enzymes catalyze the formation of a wide range of post-translational modifications some of them having no counterparts in living systems or synthetic chemistry. The investigation of radical SAM enzymes has not only illuminated unprecedented strategies used by living systems to tailor peptides into complex natural products but has also allowed to uncover novel RiPP families. In this review, we summarize the current knowledge on radical SAM enzymes catalyzing RiPP post-translational modifications and discuss their mechanisms and growing importance notably in the context of the human microbiota.

Enrichment Mechanism of Semiconducting Single-walled Carbon Nanotubes by Surfactant Amines

Science.gov (United States)

Ju, Sang-Yong; Utz, Marcel; Papadimitrakopoulos, Fotios

2009-01-01

Utilization of single-walled carbon nanotubes (SWNTs) in high-end applications hinges on separating metallic (met-) from semiconducting (sem-) SWNTs. Surfactant amines, like octadecylamine (ODA) have proven instrumental for the selective extraction of sem-SWNTs from tetrahydrofuran (THF) nanotube suspensions. The chemical shift differences along the tail of an asymmetric, diacetylenic surfactant amine were used to probe the molecular dynamics in the presence and absence of nanotubes via NMR. The results suggest that the surfactant amine head is firmly immobilized onto the nanotube surface together with acidic water, while the aliphatic tail progressively gains larger mobility as it gets farther from the SWNT. X-ray and high-resolution TEM studies indicate that the sem-enriched sample is populated mainly by small nanotube bundles containing ca. three SWNTs. Molecular simulations in conjunction with previously determined HNO3/H2SO4 oxidation depths for met- and sem-SWNTs indicate that the strong pinning of the amine surfactants on the sem-enriched SWNTs bundles is a result of a well-ordered arrangement of nitrate/amine salts separated with a monomolecular layer of H2O. Such continuous 2D arrangement of nitrate/amine salts shields the local environment adjacent to sem-enriched SWNTs bundles and maintains an acidic pH that preserves nanotube oxidation (i.e. SWNTn+). This, in turn, results in strong interactions with charge-balancing NO3- counter ions that through their association with neutralized surfactant amines provide effective THF dispersion and consequent sem-enrichment. PMID:19397291

Long-chain amine-templated synthesis of gallium sulfide and gallium selenide nanotubes

Science.gov (United States)

Seral-Ascaso, A.; Metel, S.; Pokle, A.; Backes, C.; Zhang, C. J.; Nerl, H. C.; Rode, K.; Berner, N. C.; Downing, C.; McEvoy, N.; Muñoz, E.; Harvey, A.; Gholamvand, Z.; Duesberg, G. S.; Coleman, J. N.; Nicolosi, V.

2016-06-01

We describe the soft chemistry synthesis of amine-templated gallium chalcogenide nanotubes through the reaction of gallium(iii) acetylacetonate and the chalcogen (sulfur, selenium) using a mixture of long-chain amines (hexadecylamine and dodecylamine) as a solvent. Beyond their role as solvent, the amines also act as a template, directing the growth of discrete units with a one-dimensional multilayer tubular nanostructure. These new materials, which broaden the family of amine-stabilized gallium chalcogenides, can be tentatively classified as direct large band gap semiconductors. Their preliminary performance as active material for electrodes in lithium ion batteries has also been tested, demonstrating great potential in energy storage field even without optimization.We describe the soft chemistry synthesis of amine-templated gallium chalcogenide nanotubes through the reaction of gallium(iii) acetylacetonate and the chalcogen (sulfur, selenium) using a mixture of long-chain amines (hexadecylamine and dodecylamine) as a solvent. Beyond their role as solvent, the amines also act as a template, directing the growth of discrete units with a one-dimensional multilayer tubular nanostructure. These new materials, which broaden the family of amine-stabilized gallium chalcogenides, can be tentatively classified as direct large band gap semiconductors. Their preliminary performance as active material for electrodes in lithium ion batteries has also been tested, demonstrating great potential in energy storage field even without optimization. Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr01663d

Bifunctional (cyclopentadienone)iron-tricarbonyl complexes: Synthesis, computational studies and application in reductive amination

KAUST Repository

Moulin, Solenne; Dentel, Hé lè ne; Pagnoux-Ozherelyeva, Anastassiya; Gaillard, Sylvain; Poater, Albert; Cavallo, Luigi; Lohier, Jean Franç ois; Renaud, Jean Luc

2013-01-01

. Festival of amination: Two series of modified Knölker's complexes were synthesised and applied in the reductive amination of various carbonyl derivatives with primary or secondary amines (see scheme, TIPS = triisopropylsilyl). For a mechanistic insight

Clustering of amines and hydrazines in atmospheric nucleation

Science.gov (United States)

Li, Siyang; Qu, Kun; Zhao, Hailiang; Ding, Lei; Du, Lin

2016-06-01

It has been proved that the presence of amines in the atmosphere can enhance aerosol formation. Hydrazine (HD) and its substituted derivatives, monomethylhydrazine (MMH) and unsymmetrical dimethylhydrazine (UDMH), which are organic derivatives of amine and ammonia, are common trace atmospheric species that may contribute to the growth of nucleation clusters. The structures of the hydrazine and amine clusters containing one or two common nucleation molecules (ammonia, water, methanol and sulfuric acid) have been optimized using density functional theory (DFT) methods. The clusters growth mechanism has been explored from the thermochemistry by calculating the Gibbs free energies of adding an ammonia, water, methanol or sulfuric acid molecule step by step at room temperature, respectively. The results show that hydrazine and its derivatives could enhance heteromolecular homogeneous nucleation in the earth's atmosphere.

Devulcanization of Waste Tire Rubber Using Amine Based Solvents and Ultrasonic Energy

Directory of Open Access Journals (Sweden)

Walvekar Rashmi

2018-01-01

Full Text Available This research project focuses on an alternative pathway of devulcanizing waste tire rubber by using amine based chemicals. Waste tire rubbers are known to be as toxic, non-degradable material due to their vulcanized crosslink carbon structure, and disposing of such waste could impose hazardous impacts on the environment. The current rubber recycling methods that are practiced today are rather uneconomical, non-environmentally friendly, and also producing recycled rubber with low quality due to the alteration in the main polymeric chains of waste rubber. This project aims to answer the question of whether the usage of amine can produce high quality rubber, where the properties of recycled rubber is almost the same as new/virgin rubber. With known potential of amine, it is a challenge for the chemical to selectively cleave the sulfur bonds without affecting the main carbon backbone chain in the rubber structure and diminishing much of the rubber properties. To study this research, amine-treated rubber must undergo devulcanisation process by applying heat and sonication energy. Then, the properties of the amine-treated rubber were determined through a set of characterization tests and analysis which are: gel content test to determine the weight of rubber before and after devulcanization, the thermogravimetric analysis (TGA to determine the thermal degradation and stability of rubber, and Fourier Transform Infrared Spectroscopy (FTIR to determine any structural change of the rubber. In this research so far, the first two preliminary analysis tests have been performed. The gel content test has shown that tertiary amine samples possessed a lower gel content (% of (77 – 63 %, compared to primary amine samples (falls within the range of 80%, as well as the TGA test in which tertiary amine samples degrade faster than primary amine samples (suggesting a higher degree of rubber structure breakdown. For each type of amine, the concertation of amine did

Uranium diphosphonates templated by interlayer organic amines

Energy Technology Data Exchange (ETDEWEB)

Nelson, Anna-Gay D., E-mail: nelsoa@umich.edu [Department of Civil Engineering and Geological Sciences, University of Notre Dame, IN 46556 (United States); Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI 48109-1005 (United States); Alekseev, Evgeny V. [Institute of Energy and Climate Research (IEK-6), Forschungszentrum Juelich Wilhelm-Johnen-Strasse, 52428 Juelich (Germany); Institut fuer Kristallographie, RWTH Aachen University, D-52066 Aachen (Germany); Albrecht-Schmitt, Thomas E. [Department of Civil Engineering and Geological Sciences, University of Notre Dame, IN 46556 (United States); Department of Chemistry and Biochemistry, University of Notre Dame, IN 46556 (United States); Ewing, Rodney C. [Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI 48109-1005 (United States)

2013-02-15

The hydrothermal treatment of uranium trioxide and methylenediphosphonic acid with a variety of amines (2,2-dipyridyl, triethylenediamine, ethylenediamine, and 1,10-phenanthroline) at 200 Degree-Sign C results in the crystallization of a series of layered uranium diphosphonate compounds, [C{sub 10}H{sub 9}N{sub 2}]{l_brace}UO{sub 2}(H{sub 2}O)[CH{sub 2}(PO{sub 3})(PO{sub 3}H)]{r_brace} (Ubip2), [C{sub 6}H{sub 14}N{sub 2}]{l_brace}(UO{sub 2}){sub 2}[CH{sub 2}(PO{sub 3})(PO{sub 3}H)]{sub 2}{center_dot}2H{sub 2}O{r_brace} (UDAB), [C{sub 2}H{sub 10}N{sub 2}]{sub 2}{l_brace}(UO{sub 2}){sub 2}(H{sub 2}O){sub 2}[CH{sub 2}(PO{sub 3}){sub 2}]{sub 2}{center_dot}0.5H{sub 2}O{r_brace} (Uethyl), and [C{sub 12}H{sub 9}N{sub 2}]{l_brace}UO{sub 2}(H{sub 2}O)[CH{sub 2}(PO{sub 3})(PO{sub 3}H)]{r_brace} (Uphen). The crystal structures of the compounds are based on UO{sub 7} units linked by methylenediphosphonate molecules to form two-dimensional anionic sheets in Ubip2 and UDAB, and one-dimensional anionic chains in Uethyl and Uphen, which are charge balanced by protonated amine molecules. Interaction of the amine molecules with phosphonate oxygens and water molecules results in extensive hydrogen bonding in the interlayer. These amine molecules serve both as structure-directing agents and charge-balancing cations for the anionic uranium phosphonate sheets and chains in the formation of the different coordination geometries and topologies of each structure. Reported herein are the syntheses, structural and spectroscopic characterization of the synthesized compounds. - Graphical abstract: The Raman spectra of the synthesized compounds and an illustration of the stacking of the layers with the diprotonated triethylenediamine molecules in [C{sub 6}H{sub 14}N{sub 2}]{l_brace}(UO{sub 2}){sub 2}[CH{sub 2}(PO{sub 3})(PO{sub 3}H)]{sub 2}{center_dot}2H{sub 2}O{r_brace} UDAB. Solvent water molecules are removed for clarity. The corresponding Raman spectra for the complexes synthesized is also

Factors influencing the regioselectivity of the oxidation of asymmetric secondary amines with singlet oxygen.

Science.gov (United States)

Ushakov, Dmitry B; Plutschack, Matthew B; Gilmore, Kerry; Seeberger, Peter H

2015-04-20

Aerobic amine oxidation is an attractive and elegant process for the α functionalization of amines. However, there are still several mechanistic uncertainties, particularly the factors governing the regioselectivity of the oxidation of asymmetric secondary amines and the oxidation rates of mixed primary amines. Herein, it is reported that singlet-oxygen-mediated oxidation of 1° and 2° amines is sensitive to the strength of the α-C-H bond and steric factors. Estimation of the relative bond dissociation energy by natural bond order analysis or by means of one-bond C-H coupling constants allowed the regioselectivity of secondary amine oxidations to be explained and predicted. In addition, the findings were utilized to synthesize highly regioselective substrates and perform selective amine cross-couplings to produce imines. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Chemical and Molecular Descriptors for the Reactivity of Amines with CO{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Lee, Anita S.; Kitchin, John R.

2012-10-24

Amine-based solvents are likely to play an important role in CO{sub 2} capture applications in the future, and the identification of amines with superior performance will facilitate their use in CO{sub 2} capture. While some improvements in performance will be achieved through process modifications, modifying the CO{sub 2} capture performance of an amine also implies in part an ability to modify the reactions between the amine and CO{sub 2} through development of new functionalized amines. We present a computational study of trends in the reactions between CO{sub 2} and functionalized amines with a focus on identifying molecular descriptors that determine trends in reactivity. We examine the formation of bicarbonate and carbamate species on three classes of functionalized amines: alkylamines, alkanolamines, and fluorinated alkylamines including primary, secondary and tertiary amines in each class. These functional groups span electron-withdrawing to donating behavior, hydrogen-bonding, extent of functionalization, and proximity effects of the functional groups. Electron withdrawing groups tend to destabilize CO{sub 2} reaction products, whereas electron-donating groups tend to stabilize CO{sub 2} reaction products. Hydrogen bonding stabilizes CO{sub 2} reaction products. Electronic structure descriptors based on electronegativity were found to describe trends in the bicarbonate formation energy. A chemical correlation was observed between the carbamate formation energy and the carbamic acid formation energy. The local softness on the reacting N in the amine was found to partially explain trends carbamic acid formation energy.

International ISOE Workshop - Direction Forward for the Finalization of the EG-SAM Report

International Nuclear Information System (INIS)

Okyar, H. Burcin

2014-01-01

The objective of the ISOE Expert Group on Occupational Radiation Protection in Severe Accident Management and Post-accident Recovery (EG-SAM) is to develop a report on best radiation protection management procedures for proper radiation protection job coverage during severe accident initial response and recovery efforts to identify good radiation protection practices and to organise and communicate radiation protection lessons learned from previous reactor accidents. The outcome of the work will be a new ISOE publication on Occupational Radiation Protection in severe accident management that will find broad use within the NPP radiation protection community. The EG-SAM has finalized an interim report which was presented at the Washington workshop. The interim report covered the following topics: RP Management and Organisation; RP Training and Exercises related to Severe Accident Management; Facility Configuration and Readiness; Overall Approach for Worker Protection; Monitoring and Managing the Radioactive Releases and Contamination; Key Lessons Learned from Past Accidents; Conclusions. Utilities and Regulatory Authorities have identified the factors and aspects which play key roles in achieving good practices on occupational radiation protection in severe accident management and post-accident recovery: knowledge, experience, technology, regulatory requirements and guidance, worker involvement, information exchange, training aspects, etc. They have analysed and quantified their impact on worker doses, and submitted recommendations for further work. The next step will be a final meeting of the EG-SAM for the finalization of the report with workshop inputs before its submission for approval

Analysis of amines by pH-Metrie in organic media

International Nuclear Information System (INIS)

Hamidi, A.; Elias, Abdelhamid; Achache, M.; Didi, M.

1999-01-01

Amines with long hydro carbonic strength and principally Trioclkylamines, are characterised by an important complexation mechanism for certain metals. This is the case for trioctylamine (TOA) which is very used in purification and uranium recovery from certain ores (1,2). This substance is generally found mixed with mono and di-octyl amines in commercial products and in synthesis mixtures. The purpose of this work is to develop a pH titration method in an organic media for a mixture consisted of mono, di and tri octyl amines (MOA, DOA et TOA). Adequate operating analysis condition have been proposed, based on intrinsic chemical properties for each precipitated substances (3,4). The obtained results show that this technique is recommended for qualitative and quantitative analysis of precipitated amines mixtures. The method is reproducible and the detection limit can reach 0,0001 molar

SAM - Sistema Automatizado del Método MECAP para Especificar Casos de Prueba

Directory of Open Access Journals (Sweden)

Kenyer Domínguez

2010-12-01

Full Text Available Existen cuatro elementos que son relevantes al momento de definir las pruebas: Confiabilidad, Costo, Tiempo y Calidad. El tiempo de desarrollo y el costo del producto se incrementan cuando se desean pruebas confiables y un software de calidad. Pero ¿qué se puede hacer para que los involucrados comprendan que las pruebas deben ser vistas como una red de seguridad? Si la calidad no se contempla antes de comenzar las pruebas, entonces ella no estará cuando se éstas terminen. El objetivo de este artículo es presentar la herramienta, SAM – Sistema Automatizado del Método MECAP que permite especificar Casos de Prueba a partir de Casos de Uso incorporando elementos que promueven la verificación y validación de la trazabilidad entre la Gestión de Requerimientos, el Análisis y Diseño y las Pruebas. SAM soporta el proceso de pruebas de forma automatizada, mejorando la confiabilidad de las mismas

Progress in the development of a reactivity capability in the SAM-CE system for validating fuel management codes. Interim report

International Nuclear Information System (INIS)

Lichtenstein, H.; Steinberg, H.; Troubetzkoy, E.; Cohen, M.O.; Chui, C.

1978-02-01

The SAM-CE Monte Carlo system (for three dimensional neutron, gamma ray and electron transport) has been expanded to include a reactivity capability. The implemented code modifications have effected the following improvements: (a) Doppler broadening of ENDF/B-IV based nuclear data (including fission); (b) probability table representation for the unresolved resonance range; (c) utilization of thermal scattering law data for the moderator; (d) free gas model in the absence of thermal scattering law data; (e) generalization of the nuclear element data tape structure to facilitate data management; (f) generalization of data management routines; (g) extension of the SAM-CE Complex Combinatorial Geometry capability to facilitate treatment of hexagonal lattices; (h) simultaneous use of 4 different eigenvalue estimators; (i) estimation of the eigenfunction in user prescribed spatial domains; and (j) variance reduction via stratification of source (position, energy, direction) and absorption (based on a quota sampling technique), as well as optional suppression of absorption. The new coding has undergone extensive testing, both specific (via drivers and idealized data) and integral (via comparison with previous computations). Base data have been examined for internal consistency and checked for reasonableness. A documented TRX-1 benchmark calculation has been performed. Agreement with other calculations, as well as with experiment, has served to validate the reactivity mode of SAM-CE. Further refinement of the cross section data processing component of SAM-CE (i.e., SAM-X) is suggested

Detection of Reduced Nitrogen Compounds at Rocknest Using the Sample Analysis At Mars (SAM) Instrument on the Mars Science Laboratory (MSL)

Science.gov (United States)

Stern, J. C.; Steele, A.; Brunner, A.; Coll, P.; Eigenbrode, J.; Franz, H. B.; Freissinet, C.; Glavin, D.; Jones, J. H.; Navarro-Gonzalez, R.;

Theorizing the place of evil within Sam Ukala's Radical Theatre: A ...

African Journals Online (AJOL)

The perspectives of evil in this essay will be drawn mainly from the works of such thinkers as Paul Ricoeur, St Augustine, and Friedrich Nietzsche, yet not excluding occasional insights from thinkers like Immanuel Kant, Richard B. Sewall, and so on. Sam Ukala's Akpakaland, Break a Boil and Odour of Justice are the plays to ...

Selective fluorescence quenching of nitrogen-containing polycyclic aromatic hydrocarbons by aliphatic amines

International Nuclear Information System (INIS)

Li Xiaoping; McGuffin, Victoria L.

2004-01-01

In this investigation, primary, secondary, and tertiary amines are evaluated for their efficiency and selectivity as fluorescence quenchers for polycyclic aromatic hydrocarbons (PAHs) and nitrogen-containing polycyclic aromatic hydrocarbons (N-PAHs). In general, the quenching efficiency tends to increase from primary to tertiary amine due to a greater number of alkyl groups that increase the electron-donating ability. However, the selectivity decreases from primary to tertiary amine. The effect of low concentrations of water is also examined. Because water can form hydrogen bonds with amines, the nonbonding electron pair is not available for interaction with the fluorophore, thus the quenching constant is decreased. These aliphatic amines are then applied to PAHs and N-PAHs and some interesting trends are observed. Whereas amino-PAHs remain virtually unquenched by different amines, aza-PAHs are all quenched well. The selectivity between aza-PAHs and amino-PAHs is as high as several hundred. This trend provides an easy and effective method to discriminate between these classes of N-PAHs. Moreover, the alternant aza-PAHs are quenched more than their corresponding alternant PAHs

Dosimetric comparison of the specific anthropomorphic mannequin (SAM) to 14 anatomical head models using a novel definition for the mobile phone positioning

International Nuclear Information System (INIS)

Kainz, Wolfgang; Christ, Andreas; Kellom, Tocher; Seidman, Seth; Nikoloski, Neviana; Beard, Brian; Kuster, Niels

2005-01-01

This paper presents new definitions for obtaining reproducible results in numerical phone dosimetry. Numerous numerical dosimetric studies have been published about the exposure of mobile phone users which concluded with conflicting results. However, many of these studies lack reproducibility due to shortcomings in the description of the phone positioning. The new approach was tested by two groups applying two different numerical program packages to compare the specific anthropomorphic mannequin (SAM) to 14 anatomically correct head models. A novel definition for the positioning of mobile phones next to anatomically correct head models is given along with other essential parameters to be reported. The definition is solely based on anatomical characteristics of the head. A simple up-to-date phone model was used to determine the peak spatial specific absorption rate (SAR) of mobile phones in SAM and in the anatomically correct head models. The results were validated by measurements. The study clearly shows that SAM gives a conservative estimate of the exposure in anatomically correct head models for head only tissue. Depending on frequency, phone position and head size the numerically calculated 10 g averaged SAR in the pinna can be up to 2.1 times greater than the peak spatial SAR in SAM. Measurements in small structures, such as the pinna, will significantly increase the uncertainty; therefore SAM was designed for SAR assessment in the head only. Whether SAM will provide a conservative value for the pinna depends on the pinna SAR limit of the safety standard considered

Early Post-Irradiation Changes in the Metabolism of Biogenic Amines; Les Changements Precoces du Metabolisme des Amines Biogenes apres Irradiation

Energy Technology Data Exchange (ETDEWEB)

Deanovic, Z [Institut Rudjer Boskovic, Zagreb, Yugoslavia (Croatia)

1971-03-15

There is accumulating evidence for the radiation-induced release of biogenic amines from their body stores. Having in mind the high patho-physiological activity of these ''local'' hormones and ''neuro-hormones'', it is reasonable to assume that they play an important role in the pathogenesis of the acute radiation syndrome. Under these pathological conditions the possible synergic and antagonistic effects of biogenic amines due to their complex interactions must be taken into consideration. The extent and dose-dependence of post-irradiation changes in the metabolism of histamine, serotonin, catecholamines and acetylcholine will be examined regarding particularly the search for biochemical indicators of radiation injury. The determination of bio-amines and their metabolites in urine seems to be a suitable method for following up those metabolic changes which could be of a biodosimetrical and/or prognostical value. Data published on this subject, obtained in experimental animals as well as in man, have been reviewed and the applicability of these tests is discussed. (author) [French] Des preuves se sont accumulees, qui demontrent que les amines biogenes sont liberees de leurs depots sous l'effet des rayonnements ionisants. Etant donne la grande activite pathophysiologique de ces hormones 'locales' et 'neurohormones', il est raisonnable de considerer que ces substances biogenes jouent un role important dans la pathogenese du syndrome aigu d'irradiation. Dans ces conditions pathologiques il faut tenir compte des effets synergiques et antagonistes des bio-amines, lies a des interactions compliquees. Les changements metaboliques en fonction de la dose recue font l'objet d'un examen qui englobe les alterations quantitatives de .'histamine, de la serotonine, des catecholamines et de l'acetylcholine et dont l'objectif est la recherche sur des indicateurs biochimiques de la lesion provoquee par l'irradiation. L'analyse des bio-amines et de leurs metabolites dans les urines

Elp3 and RlmN: A tale of two mitochondrial tail-anchored radical SAM enzymes in Toxoplasma gondii.

Science.gov (United States)

Padgett, Leah R; Lentini, Jenna M; Holmes, Michael J; Stilger, Krista L; Fu, Dragony; Sullivan, William J

2018-01-01

Radical S-adenosylmethionine (rSAM) enzymes use a 5'-deoxyadensyl 5'-radical to methylate a wide array of diverse substrates including proteins, lipids and nucleic acids. One such enzyme, Elongator protein-3 (TgElp3), is an essential protein in Toxoplasma gondii, a protozoan parasite that can cause life-threatening opportunistic disease. Unlike Elp3 homologues which are present in all domains of life, TgElp3 localizes to the outer mitochondrial membrane (OMM) via a tail-anchored trafficking mechanism in Toxoplasma. Intriguingly, we identified a second tail-anchored rSAM domain containing protein (TgRlmN) that also localizes to the OMM. The transmembrane domain (TMD) on Toxoplasma Elp3 and RlmN homologues is required for OMM localization and has not been seen beyond the chromalveolates. Both TgElp3 and TgRlmN contain the canonical rSAM amino acid sequence motif (CxxxCxxC) necessary to form the 4Fe-4S cluster required for tRNA modifications. In E. coli, RlmN is responsible for the 2-methlyadenosine (m2A) synthesis at purine 37 in tRNA while in S. cerevisiae, Elp3 is necessary for the formation of 5-methoxycarbonylmethyl-2-thiouridine (mcm5s2U) at the wobble tRNA position. To investigate why these two rSAM enzymes localize to the mitochondrion in Toxoplasma, and whether or not TgRlmN and TgElp3 possess tRNA methyltransferase activity, a series of mutational and biochemical studies were performed. Overexpression of either TgElp3 or TgRlmN resulted in a significant parasite replication defect, but overexpression was tolerated if either the TMD or rSAM domain was mutated. Furthermore, we show the first evidence that Toxoplasma tRNAGlu contains the mcm5s2U modification, which is the putative downstream product generated by TgElp3 activity.

Extraction of uranyl sulfate with primary amine

International Nuclear Information System (INIS)

Mrnka, M.; Bizek, V.; Nekovar, P.; Cizevska, S.; Schroetterova, D.

1984-01-01

PRIMENE JM-T was used for extraction. Its composition was found to approach the general formula C 21 H 43 NH 2 . It was found that the extraction of uranyl sulfate is lower in case of a higher steady-state concentration of sulfuric acid in the aqueous phase. Extraction is accompanied with coextraction of water. The results obtained showed that uranyl sulfate passes into the organic phase by two mechanisms: extraction with amine sulfate and extraction with free amine. A mathematical description of the process was made based on the obtained results. (E.S.)

Poly(Amido Amine)s containing agmatine and butanol side chains as efficient gene carriers

NARCIS (Netherlands)

Won, Young-Wook; Ankone, Martinus J.K.; Engbersen, Johannes F.J.; Feijen, Jan; Kim, S.W.

2016-01-01

A new type of bioreducible poly(amido amine) copolymer is synthesized by the Michael addition polymerization of cystamine bisacrylamide (CBA) with 4-aminobutylguanidine (agmatine, AGM) and 4-aminobutanol (ABOL). Since the positively charged guanidinium groups of AGM and the hydroxybutyl groups of

Comparative study of the conformational lock, dissociative thermal inactivation and stability of euphorbia latex and lentil seedling amine oxidases.

Science.gov (United States)

Amani, M; Moosavi-Movahedi, A A; Floris, G; Longu, S; Mura, A; Moosavi-Nejad, S Z; Saboury, A A; Ahmad, F

2005-04-01

The thermal stability of copper/quinone containing amine oxidases from Euphorbia characias latex (ELAO) and lentil seedlings (LSAO) was measured in 100 mM potassium phosphate buffer (pH 7.0) following changes in absorbance at 292 nm. ELAO was shown to be about 10 degrees C more stable than LSAO. The dissociative thermal inactivation of ELAO was studied using putrescine as substrate at different temperatures in the range 47-70 degrees C, and a "conformational lock" was developed using the theory pertaining to oligomeric enzyme. Moreover ELAO was shown to be more stable towards denaturants than LSAO, as confirmed by dodecyl trimethylammonium bromide denaturation curves. A comparison of the numbers of contact sites in inter-subunits of ELAO relative to LSAO led us to conclude that the higher stability of ELAO to temperature and towards denaturants was due to the presence of larger number of contact sites in the conformational lock of the enzyme. This study also gives a putative common mechanism for thermal inactivation of amine oxidases and explains the importance of C-terminal conserved amino acids residues in this class of enzymes.

Multi-Objective Optimization for Solid Amine CO2 Removal Assembly in Manned Spacecraft

Directory of Open Access Journals (Sweden)

Rong A

2017-07-01

Full Text Available Carbon Dioxide Removal Assembly (CDRA is one of the most important systems in the Environmental Control and Life Support System (ECLSS for a manned spacecraft. With the development of adsorbent and CDRA technology, solid amine is increasingly paid attention due to its obvious advantages. However, a manned spacecraft is launched far from the Earth, and its resources and energy are restricted seriously. These limitations increase the design difficulty of solid amine CDRA. The purpose of this paper is to seek optimal design parameters for the solid amine CDRA. Based on a preliminary structure of solid amine CDRA, its heat and mass transfer models are built to reflect some features of the special solid amine adsorbent, Polyethylenepolyamine adsorbent. A multi-objective optimization for the design of solid amine CDRA is discussed further in this paper. In this study, the cabin CO2 concentration, system power consumption and entropy production are chosen as the optimization objectives. The optimization variables consist of adsorption cycle time, solid amine loading mass, adsorption bed length, power consumption and system entropy production. The Improved Non-dominated Sorting Genetic Algorithm (NSGA-II is used to solve this multi-objective optimization and to obtain optimal solution set. A design example of solid amine CDRA in a manned space station is used to show the optimal procedure. The optimal combinations of design parameters can be located on the Pareto Optimal Front (POF. Finally, Design 971 is selected as the best combination of design parameters. The optimal results indicate that the multi-objective optimization plays a significant role in the design of solid amine CDRA. The final optimal design parameters for the solid amine CDRA can guarantee the cabin CO2 concentration within the specified range, and also satisfy the requirements of lightweight and minimum energy consumption.

Effect of foamability index of short chain alkyl amines on flotation of quartz

Directory of Open Access Journals (Sweden)

Szczerkowska Sabina

2016-01-01

Full Text Available Amines can be used for flotation of various minerals, especially quartz. The flotation efficiency of quartz depends on the amine type and dose. It was proved that the shorter alkyl amine, higher amine concentration has to be used to recover quartz at the same level. In flotation amines play a role of both collectors and frothers. The ability of a amine to collect particles can be expressed in the form of contact angle, while the foaming properties by different parameters including dynamic foamability index (DFI and critical coalescence concentration (CCC. Determination of DFI and CCC requires advanced techniques and methods. Therefore, in this paper a rapid and facile method for determination of foaming properties of amines and also other surfactants was used. It was based on measuring the initial foam and froth heights in a conventional flotation machine at different concentrations of surfactants. The foam height-concentration curve was described by utilizing an empirical equation which was based on one-adjustable parameter called the foamability index (FI. In this work the foamability index was determined for butylamine (ButNH2, hexylamine (HexNH2 and octylamine (OctNH2 as examples of short chain alkyl amines. The determined foamability indices were 92, 12 and 4 mg/dm3 for ButNH2, HexNH2 and OctNH2, respectively. It was shown that when the flotation results of quartz were presented in the form of recovery versus normalized amine concentration in relation to the foamability index (c/FI, all the experimental data points converged to one curve. It indicates that amines act similarly but at different concentrations expressed as FI. The foamability index seems to be a useful parameter for characterizing any flotation frother.

Factors influencing phase-disengagement rates in solvent-extraction systems employing tertiary amine extractants

International Nuclear Information System (INIS)

Moyer, B.A.; McDowell, W.J.

1981-01-01

The primary purpose of the present investigation was to examine the effects of amine size and structure on phase disengagement. Nine commercial tertiary amines were tested together with four laboratory-quality amines for uranium extraction and both organic-continuous (OC) and aqueous-continuous (AC) phase disengagement under Amex-type conditions. Synthetic acid sulfate solutions with and without added colloidal silica and actual ore leach solutions were used as the aqueous phases. Phase disengagement results were correlated with amine size and branching and solution wetting behavior on a silicate (glass) surface. The results suggest that the performance of some Amex systems may be improved by using branched chain tertiary amine extractants of higher molecular weight than are now normally used

Facile and Green Synthesis of Saturated Cyclic Amines

Directory of Open Access Journals (Sweden)

Arruje Hameed

2017-10-01

Full Text Available Single-nitrogen containing saturated cyclic amines are an important part of both natural and synthetic bioactive compounds. A number of methodologies have been developed for the synthesis of aziridines, azetidines, pyrrolidines, piperidines, azepanes and azocanes. This review highlights some facile and green synthetic routes for the synthesis of unsubstituted, multisubstituted and highly functionalized saturated cyclic amines including one-pot, microwave assisted, metal-free, solvent-free and in aqueous media.

Calcium(ii)-catalyzed enantioselective conjugate additions of amines.

Science.gov (United States)

Uno, Brice E; Dicken, Rachel D; Redfern, Louis R; Stern, Charlotte M; Krzywicki, Greg G; Scheidt, Karl A

2018-02-14

The direct enantioselective chiral calcium(ii)·phosphate complex (Ca[CPA] 2 )-catalyzed conjugate addition of unprotected alkyl amines to maleimides was developed. This mild catalytic system represents a significant advance towards the general convergent asymmetric amination of α,β-unsaturated electrophiles, providing medicinally relevant chiral aminosuccinimide products in high yields and enantioselectivities. Furthermore, the catalyst can be reused directly from a previously chromatographed reaction and still maintain both high yield and selectivity.

Deposition of phospholipid layers on SiO{sub 2} surface modified by alkyl-SAM islands

Energy Technology Data Exchange (ETDEWEB)

Tero, R.; Takizawa, M.; Li, Y.J.; Yamazaki, M.; Urisu, T

2004-11-15

Formation of the supported planar bilayer of dipalmitoylphosphatidylcholine (DPPC) on SiO{sub 2} surfaces modified with the self-assembled monolayer (SAM) of octadecyltrichlorosilane (OTS) has been investigated by atomic force microscopy (AFM). DPPC was deposited by the fusion of vesicles on SiO{sub 2} surfaces with OTS-SAM islands of different sizes and densities. The DPPC bilayer membrane formed self-organizingly on the SiO{sub 2} surface with small and sparse OTS islands, while did not when the OTS islands were larger and denser. The relative size between the vesicles and the SiO{sub 2} regions is the critical factor for the formation of the DPPC bilayer membrane.

Biogenic Amines in Insect Antennae

Directory of Open Access Journals (Sweden)

Marianna I. Zhukovskaya

2017-06-01

Full Text Available Insect antenna is a multisensory organ, each modality of which can be modulated by biogenic amines. Octopamine (OA and its metabolic precursor tyramine (TA affect activity of antennal olfactory receptor neurons. There is some evidence that dopamine (DA modulates gustatory neurons. Serotonin can serve as a neurotransmitter in some afferent mechanosensory neurons and both as a neurotransmitter and neurohormone in efferent fibers targeted at the antennal vessel and mechanosensory organs. As a neurohormone, serotonin affects the generation of the transepithelial potential by sensillar accessory cells. Other possible targets of biogenic amines in insect antennae are hygro- and thermosensory neurons and epithelial cells. We suggest that the insect antenna is partially autonomous in the sense that biologically active substances entering its hemolymph may exert their effects and be cleared from this compartment without affecting other body parts.

Poly(amido)amine (PAMAM) dendrimer-cisplatin complexes for chemotherapy of cisplatin-resistant ovarian cancer cells

Science.gov (United States)

Yellepeddi, Venkata Kashyap; Vangara, Kiran Kumar; Palakurthi, Srinath

2013-09-01

Dendrimer-cisplatin complexes were prepared using PAMAM dendrimers with terminal -NH2 and -COOH groups as well as biotin-conjugated dendrimers. Preformulation parameters of dendrimer-cisplatin complexes were studied using differential scanning calorimetry (DSC) and inductively coupled plasma-mass spectrometry (ICP-MS). Cytotoxicity and mechanism of cytotoxicity of dendrimer-cisplatin complexes was investigated in OVCAR-3, SKOV, A2780 and cisplatin-resistant CP70 human ovarian cancer cell lines. The loading of cisplatin in dendrimers was 11 % (w/w). PAMAM G4 dendrimers with amine surface groups (biotinylated and native) have shown 2.5- to 3.0-fold reduction in IC50 values in ovarian cancer cells when compared with carboxylate surface dendrimers ( p cisplatin complexes resulted in a 7.0-fold increase ( p cisplatin chemotherapy of ovarian cancer.

Effect of amine uptake inhibitors on the uptake of 14C-bretylium in intact and degenerating sympathetic nerves of the rat

International Nuclear Information System (INIS)

Almgren, O.

1981-01-01

The effect of different amine uptake inhibitors on the accumulation of 14 C-bretylium in sympathetically denervated or decentralized salivary glands were studied in vivo in rats 11-14 hours after the surgical intervention. The time period chosen is known to be critical for the delaying effect of bretylium on the degeneration transmitter release in sympathetically innervated organs. Cocaine, desmethylimipramine (DMI), protriptyline or reserpine all depressed the uptake of 14 C-bretylium in both denervated and decentralized salivary glands, cocaine being the most efficient one. DMI and protriptyline, but not cocaine inhibit the degeneration delaying effect of bretylium, while all three agents inhibit amine uptake at level of the nerve cell membrane. Apparently, bretylium reaches the critical sites of its degeneration delaying action by the axonal amine pump but only a small fraction of the drug entering the degenerating adrenergic nerve terminal is needed at the critical sites to interact with the degeneration processes. The difference between the tricyclic antidepressants on one hand and cocaine on the other with respect to the effect on the degeneration delaying action of bretylium, must depend on some action different from the axonal membrane uptake inhibition. Reserpine which is known not to interfere with the delaying effect of bretylium on the denervation degeneration did reduce the uptake of 14 C-bretylium. This fact seems to indicate that the site of action of bretylium is located outside the adrenergic nerve granules. (author)

Role of amine structure on carbon dioxide adsorption from ultradilute gas streams such as ambient air.

Science.gov (United States)

Didas, Stephanie A; Kulkarni, Ambarish R; Sholl, David S; Jones, Christopher W

2012-10-01

A fundamental study on the adsorption properties of primary, secondary, and tertiary amine materials is used to evaluate what amine type(s) are best suited for ultradilute CO(2) capture applications. A series of comparable materials comprised of primary, secondary, or tertiary amines ligated to a mesoporous silica support via a propyl linker are used to systematically assess the role of amine type. Both CO(2) and water adsorption isotherms are presented for these materials in the range relevant to CO(2) capture from ambient air and it is demonstrated that primary amines are the best candidates for CO(2) capture from air. Primary amines possess both the highest amine efficiency for CO(2) adsorption as well as enhanced water affinity compared to other amine types or the bare silica support. The results suggest that the rational design of amine adsorbents for the extraction of CO(2) from ambient air should focus on adsorbents rich in primary amines. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Copper(II)-catalyzed electrophilic amination of quinoline N-oxides with O-benzoyl hydroxylamines.

Science.gov (United States)

Li, Gang; Jia, Chunqi; Sun, Kai; Lv, Yunhe; Zhao, Feng; Zhou, Kexiao; Wu, Hankui

2015-03-21

Copper acetate-catalyzed C-H bond functionalization amination of quinoline N-oxides was achieved using O-benzoyl hydroxylamine as an electrophilic amination reagent, thereby affording the desired products in moderate to excellent yields. Electrophilic amination can also be performed in good yield on a gram scale.

Wide Range Vacuum Pumps for the SAM Instrument on the MSL Curiosity Rover

Science.gov (United States)

Sorensen, Paul; Kline-Schoder, Robert; Farley, Rodger

2014-01-01

Creare Incorporated and NASA Goddard Space Flight Center developed and space qualified two wide range pumps (WRPs) that were included in the Sample Analysis at Mars (SAM) instrument. This instrument was subsequently integrated into the Mars Science Laboratory (MSL) "Curiosity Rover," launched aboard an Atlas V rocket in 2011, and landed on August 6, 2012, in the Gale Crater on Mars. The pumps have now operated for more than 18 months in the Gale Crater and have been evacuating the key components of the SAM instrument: a quadrupole mass spectrometer, a tunable laser spectrometer, and six gas chromatograph columns. In this paper, we describe the main design challenges and the ways in which they were solved. This includes the custom design of a miniaturized, high-speed motor to drive the turbo drag pump rotor, analysis of rotor dynamics for super critical operation, and bearing/lubricant design/selection.

Catalyst Deactivation Reactions : The Role of Tertiary Amines Revisited

NARCIS (Netherlands)

Novarino, Elena; Rios, Itzel Guerrero; van der Veer, Siebe; Meetsma, Auke; Hessen, Bart; Bouwkamp, Marco W.

2011-01-01

Decamethylzirconocene cation [Cp*2ZrMe](+) (2) decomposes in bromobenzene-d(5) solution to generate sigma-aryl species [Cp*Zr-2(2-C6H4Br-kappa Br,C)][B(C6F5)(4)] (3). This a-bond metathesis reaction is catalyzed by tertiary amines via a two-step mechanism, in which the amine acts as a proton relay.

Functional expression of amine oxidase from Aspergillus niger (AO-I) in Saccharomyces cerevisiae.

Science.gov (United States)

Kolaríková, Katerina; Galuszka, Petr; Sedlárová, Iva; Sebela, Marek; Frébort, Ivo

2009-01-01

The aim of this work was to prepare recombinant amine oxidase from Aspergillus niger after overexpressing in yeast. The yeast expression vector pDR197 that includes a constitutive PMA1 promoter was used for the expression in Saccharomyces cerevisiae. Recombinant amine oxidase was extracted from the growth medium of the yeast, purified to homogeneity and identified by activity assay and MALDI-TOF peptide mass fingerprinting. Similarity search in the newly published A. niger genome identified six genes coding for copper amine oxidase, two of them corresponding to the previously described enzymes AO-I a methylamine oxidase and three other genes coding for FAD amine oxidases. Thus, A. niger possesses an enormous metabolic gear to grow on amine compounds and thus support its saprophytic lifestyle.

Enzymatic network for production of ether amines from alcohols

DEFF Research Database (Denmark)

Palacio, Cyntia M.; Crismaru, Ciprian G.; Bartsch, Sebastian

2016-01-01

We constructed an enzymatic network composed of three different enzymes for the synthesis of valuable ether amines. The enzymatic reactions are interconnected to catalyze the oxidation and subsequent transamination of the substrate and to provide cofactor recycling. This allows production...... of the desired ether amines from the corresponding ether alcohols with inorganic ammonium as the only additional substrate. To examine conversion, individual and overall reaction equilibria were established. Using these data, it was found that the experimentally observed conversions of up to 60% observed...... for reactions containing 10mM alcohol and up to 280mM ammonia corresponded well to predicted conversions. The results indicate that efficient amination can be driven by high concentrations of ammonia and may require improving enzyme robustness for scale-up....

Ultrafast relaxation dynamics of amine-substituted bipyridyl ruthenium(II) complexes

Science.gov (United States)

Song, Hongwei; Wang, Xian; Yang, WenWen; He, Guiying; Kuang, Zhuoran; Li, Yang; Xia, Andong; Zhong, Yu-Wu; Kong, Fan'ao

2017-09-01

The excited state properties of a series of ruthenium(II) amine-substituted bipyridyl complexes, [Ru(bpy)n(NNbpy)3-n]2+, were investigated by steady-state and transient absorption spectroscopy, as well as quantum chemical calculations. The steady-state absorption spectra of these complexes in CH3CN show a distinct red-shift of the 1MLCT absorption with increasing numbers of amine substituent, whereas the emission spectra indicate an energy gap order of [Ru(bpy)3]2+ > [Ru(bpy)2(NNbpy)]2+ > [Ru(NNbpy)3]2+ > [Ru(bpy)(NNbpy)2]2+. Nanosecond, femtosecond transient absorption and electrochemical measurements suggest that NNbpy ligand has a strong influence on the electronic and emission properties of these complexes, due to electron-rich amine substituent. We illustrate how the numbers of amine substituent modulate the spectroscopic properties of transition metal complexes, which is related to the design of new electro-active systems with novel photoelectrochemical properties.

Nano ZnO/amine composites antimicrobial additives to acrylic paints

Directory of Open Access Journals (Sweden)

H.B. Kamal

2015-12-01

Full Text Available Nano ZnO has been widely used as an antimicrobial agent not only for food packaging purposes but also in many coating processes. The present work is meant to enhance such functions through the preparation of sustainable and safe conduct of nano ZnO composites with amine derivatives that are characterized by their antimicrobial and anti-fouling functional activities. The results obtained revealed a more comprehensive approach to the antimicrobial function based on the reported active oxide species role. The oxide/amine composites and the acrylic emulsion paint were characterized chemically and structurally through FT-IR, TGA and TEM supported by biological assessment of each ZnO/amine composite action. Results of the study concluded that equilibrium between the nano ZnO particles size, their dispersion form, and amine ability to stabilize the actively produced oxygen species responsible for the antimicrobial function, should all be accounted for when persistence of antimicrobial agent efficiency is regarded.

Alkylselenite-catalyzed Oxidative Carbonylation of Amines: Density Functional Theory Study

Energy Technology Data Exchange (ETDEWEB)

Hwang, Sun; Kim, Hoon Sik; Cheong, Minserk [Kyung Hee Univ., Seoul (Korea, Republic of)

2012-11-15

Ureas and carbamates have been conventionally produced by the reaction of amines with phosgene. However, phosgenation processes raise severe environmental concerns, which are attributed to the toxicity of phosgene and the formation of corrosive hydrogen chloride as a co-product. The considerable industrial interest in replacing current phosgene-based processes prompted several methods using non-phosgene routes including carbonylation of amines or nitro compounds and carbomethoxylation of amines with dialkylcarbonates. Among these, catalytic oxidative carbonylation of an amine in the presence of alcohol has been studied most extensively. Catalytic systems based on precious metals such as Rh and Pd are commonly used for this purpose, but most of these catalytic systems suffer from either low reactivity or severe reaction conditions such as high temperature and pressures. In conclusion, the facile change of selenium oxidation state by CO and O{sub 2} might be the main reason for the activity of the selenium catalyst for this reaction.

Alkylselenite-catalyzed Oxidative Carbonylation of Amines: Density Functional Theory Study

International Nuclear Information System (INIS)

Hwang, Sun; Kim, Hoon Sik; Cheong, Minserk

2012-01-01

Ureas and carbamates have been conventionally produced by the reaction of amines with phosgene. However, phosgenation processes raise severe environmental concerns, which are attributed to the toxicity of phosgene and the formation of corrosive hydrogen chloride as a co-product. The considerable industrial interest in replacing current phosgene-based processes prompted several methods using non-phosgene routes including carbonylation of amines or nitro compounds and carbomethoxylation of amines with dialkylcarbonates. Among these, catalytic oxidative carbonylation of an amine in the presence of alcohol has been studied most extensively. Catalytic systems based on precious metals such as Rh and Pd are commonly used for this purpose, but most of these catalytic systems suffer from either low reactivity or severe reaction conditions such as high temperature and pressures. In conclusion, the facile change of selenium oxidation state by CO and O 2 might be the main reason for the activity of the selenium catalyst for this reaction

From caffeine to fish waste: amine compounds present in food and drugs and their interactions with primary amine oxidase.

LENUS (Irish Health Repository)

Olivieri, Aldo

2011-07-01

Tissue bound primary amine oxidase (PrAO) and its circulating plasma-soluble form are involved, through their catalytic activity, in important cellular roles, including the adhesion of lymphocytes to endothelial cells during various inflammatory conditions, the regulation of cell growth and maturation, extracellular matrix deposition and maturation and glucose transport. PrAO catalyses the oxidative deamination of several xenobiotics and has been linked to vascular toxicity, due to the generation of cytotoxic aldehydes. In this study, a series of amines and aldehydes contained in food and drugs were tested via a high-throughput assay as potential substrates or inhibitors of bovine plasma PrAO. Although none of the compounds analyzed were found to be substrates for the enzyme, a series of molecules, including caffeine, the antidiabetics phenformin and tolbutamide and the antimicrobial pentamidine, were identified as PrAO inhibitors. Although the inhibition observed was in the millimolar and micromolar range, these data show that further work will be necessary to elucidate whether the interaction of ingested biogenic or xenobiotic amines with PrAO might adversely affect its biological roles.

Metal Monolithic Amine-grafted Zeolite for CO{sub 2} Capture

Energy Technology Data Exchange (ETDEWEB)

Chuang, Steven

2011-03-31

The solid amine sorbent for CO{sub 2} capture process has advantages of simplicity and low operating cost compared to the MEA (monoethanolamine) process. Solid amine sorbents reported so far suffered from either low CO{sub 2} capture capacity or low stability. The solid amine sorbent developed in this project exhibited more than 3.2 mmol/g and degraded less than 10% even after 500 cycles of heating and cooling in absence of steam. The presence of steam further enhanced CO{sub 2} capture capacity. The cost of the sorbent is estimated to be less than $7.00/lb. This sorbent was developed using the results of in situ infrared spectroscopic study. Infrared results showed that CO{sub 2} adsorbs on TEPA (tetraethylenepentamine)/PEG (polyethylene glycol) as carbamates and bicarbonates. The CO{sub 2} adsorption capacity and oxidation resistance of the amine sorbent can be enhanced by the interactions between NH{sub 2} of TEPA molecules with the OH group of PEG molecules. PEG was also found to be effectively disperse and immobilize the aromatic amines for SO{sub 2} adsorption. The infrared study also showed that SiO{sub 2} is a significantly better support than zeolites due to its proper hydrophobicity. The results of this study led to the development of a high performance solid amine sorbent under simulated gas flow condition in a fixed bed, a fluidized bed, and a metal monolith unit. This study showed heat transfer could become a major technical issue in scaling up a fixed bed adsorber. The use of the fluidized bed and metal monoliths can alleviate the heat transfer issue. The metal monolith could be suitable for small scale applications due to the high cost of manufacturing; the fluidized bed mode would be most suitable for large scale applications. Preliminary economic analysis suggested that the Akron solid amine process would cost 45% less than that of MEA process.

Concentration, size distribution and dry deposition of amines in atmospheric particles of urban Guangzhou, China

Science.gov (United States)

Liu, Fengxian; Bi, Xinhui; Zhang, Guohua; Peng, Long; Lian, Xiufeng; Lu, Huiying; Fu, Yuzhen; Wang, Xinming; Peng, Ping'an; Sheng, Guoying

2017-12-01

Size-segregated PM10 samples were collected in Guangzhou, China during autumn of 2014. Nine amines, including seven aliphatic amines and two heterocyclic amines, were detected using a gas chromatography-mass spectrometer after derivatization by benzenesulfonyl chloride. The total concentration of the nine amines (Ʃamines) was 79.6-140.9 ng m-3 in PM10. The most abundant species was methylamine (MA), which had a concentration of 29.2-70.1 ng m-3. MA, dimethylamine (DMA), diethylamine (DEA) and dibutylamine (DBA) were the predominant amines in the samples and accounted for approximately 80% of Ʃamines in each size segment. Two heterocyclic amines, pyrrolidine (PYR) and morpholine (MOR), were detected in all samples and had average concentrations of 1.14 ± 0.37 and 1.89 ± 0.64 ng m-3, respectively, in particles with aerodynamic diameters ammonium ranged from 0.0068 to 0.0107 in particles with diameters <1.5 μm, and the maximum ratio occurred in the smallest particles (diameter< 0.49 μm). The average dry deposition flux and velocity of Ʃamines in PM10 were 7.9 ± 1.6 μg m-2 d-1 and 0.084 ± 0.0021 cm s-1, respectively. The results of this study provide essential information on the contribution of amines to secondary organic aerosols and dry removal mechanisms in urban areas.

Nucleophilic addition of amines to the activated ethylene bond in non-aqueous media

International Nuclear Information System (INIS)

Perepichka, Igor F.; Popov, Anatolii F.

1995-01-01

The kinetics of addition of a number of primary and secondary aliphatic amines to trans-(2-furyl) nitro ethylene (1) has been studied in solvents of various polarities (from acetonitrile, ε 37.5, to heptane, ε 1.89). It has been shown that the reaction is catalysed both by the amine reagent and by tertiary amines. On the basis of analyzing the observed kinetic regularities a stepwise reaction mechanism has been proposed which involves formation of zwitterionic intermediate (3) at the first equilibrium step (k 1 , K 1 ) which is then converted into the reaction product by means of proton transfer in parallel routes, the non-catalytic one (k 2 ) and that catalysed by the initial (K 3 ) or tertiary (K 4 ) amine. The observed high values of the deuterium isotope effects in the reaction (K H /K D ∼ 2.3 - 8.9) confirm that proton transfer occurs in the rate-limiting step of the reaction (primary kinetic isotope effect). The third order by amine kinetic route is observed in low polar media which is due to participation of amine dimers (R 2 NH HNR 2 ) in the reaction. The observed kinetic regularities are compared with those for the nucleophilic aromatic substitution reactions in low-polar media, and the conclusion has been made that the reaction route of the third order by amine proceeds as reversible nucleophilic attack by amine dimer and following base-catalysed transformation of the intermediate into the product. (author)

Corrosion inhibition of brass by aliphatic amines

International Nuclear Information System (INIS)

Taha, K. K.; Sheshadri, B. S; Ahmed, M. F.

2005-01-01

Aliphatic amines hexylamine (HCA), octylamine (OCA) and decylamine (DCA) have been used as corrosion inhibitors for (70/30) brass in 0.I M HCIO 4 . The inhibitor efficiency (%P) calculated using weight loss, Tafel extrapolation, linear polarization and impedance methods was found to be in the order DCA> OCA> HCA. These adsorb on brass surface following bockris-swinkels' isotherm. DCA, OCA and HCA displaced 4, 3 and 2 molecules of water from interface respectively. Displacement of water molecules brought a great reorganization of double layer at the interface. These amines during corrosion form complexes with dissolved zinc and copper ions.(Author)

Franchising as a Potential Growth Strategy for a Small Business : A Case of Sam-Chi Fast Food Restaurant

OpenAIRE

Odunsi, Sadiq

2015-01-01

The purpose of this study was to find out whether Sam-Chi fast food restaurant can grow through franchising as well as to give the owners recommendations on how to effectively adopt the franchising business model as a means to grow their business. Sam-Chi restaurant is situated in Lagos, Nigeria and the restaurant is owned and operated by Samuel Okore and his wife Chichi Okore. The theoretical framework of this research is separated into two sections. The first section covers the growth of a ...

A one-pot chemoselective synthesis of secondary amines by using a biomimetic electrocatalytic system

International Nuclear Information System (INIS)

Largeron, Martine

2009-01-01

A one-pot electrochemically induced oxidation-imine formation-reduction route to secondary amines is described in detail. The key step of the process consists of the o-iminoquinone-mediated chemoselective catalytic oxidation of a primary aliphatic amine substrate, in the presence of a second amine used as the alkylating agent. Through the examination of the scope of the reaction by systematically varying both amine substrate and amine alkylating agent, it can be shown that this reaction sequence, leaving ammonia as the sole by-product, allows the rapid synthesis of various secondary amines in moderate to good yields. This process, that highlights the pre-eminent green advantages of electrochemical synthesis, especially the utilization of electricity as energy instead of chemical reagents, high atom economy as well as ambient temperature and pressure, could be a mild alternative to already reported synthetic methods.

A one-pot chemoselective synthesis of secondary amines by using a biomimetic electrocatalytic system

Energy Technology Data Exchange (ETDEWEB)

Largeron, Martine [UMR CNRS 8638, Synthese et Structure de Molecules d' nteret Pharmacologique, Universite Paris Descartes, Faculte des Sciences Pharmaceutiques et Biologiques, 4 Avenue de l' Observatoire, 75270 Paris Cedex 06 (France)], E-mail: martine.largeron@parisdescartes.fr

2009-09-01

A one-pot electrochemically induced oxidation-imine formation-reduction route to secondary amines is described in detail. The key step of the process consists of the o-iminoquinone-mediated chemoselective catalytic oxidation of a primary aliphatic amine substrate, in the presence of a second amine used as the alkylating agent. Through the examination of the scope of the reaction by systematically varying both amine substrate and amine alkylating agent, it can be shown that this reaction sequence, leaving ammonia as the sole by-product, allows the rapid synthesis of various secondary amines in moderate to good yields. This process, that highlights the pre-eminent green advantages of electrochemical synthesis, especially the utilization of electricity as energy instead of chemical reagents, high atom economy as well as ambient temperature and pressure, could be a mild alternative to already reported synthetic methods.

In Situ Preparation of Polyether Amine Functionalized MWCNT Nanofiller as Reinforcing Agents

Directory of Open Access Journals (Sweden)

Ayber Yıldrım

2014-01-01

Full Text Available In situ preparation of polyether amine functionalized cross-linked multiwalled carbon nanotube (MWCNT nanofillers may improve the thermal and mechanical properties of the composites in which they are used as reinforcing agents. The reduction and functionalization of MWCNT using ethylenediamine in the presence of polyether amine produced stitched MWCNT's due to the presence of two amine (–NH2 functionalities on both sides of the polymer. Polyether amine was chosen to polymerize the carboxylated MWCNT due to its potential to form bonds with the amino groups and carboxyl groups of MWCNT which produces a resin used as polymeric matrix for nanocomposite materials. The attachment of the polyether amine (Jeffamine groups was verified by TGA, FT-IR, XRD, SEM, and Raman spectroscopy. The temperature at which the curing enthalpy is maximum, observed by DSC, was shifted to higher values by adding functionalized MWCNT. SEM images show the polymer formation between MWCNT sheets.

A practical and catalyst-free trifluoroethylation reaction of amines using trifluoroacetic acid

Science.gov (United States)

Andrews, Keith G.; Faizova, Radmila; Denton, Ross M.

2017-06-01

Amines are a fundamentally important class of biologically active compounds and the ability to manipulate their physicochemical properties through the introduction of fluorine is of paramount importance in medicinal chemistry. Current synthesis methods for the construction of fluorinated amines rely on air and moisture sensitive reagents that require special handling or harsh reductants that limit functionality. Here we report practical, catalyst-free, reductive trifluoroethylation reactions of free amines exhibiting remarkable functional group tolerance. The reactions proceed in conventional glassware without rigorous exclusion of either moisture or oxygen, and use trifluoroacetic acid as a stable and inexpensive fluorine source. The new methods provide access to a wide range of medicinally relevant functionalized tertiary β-fluoroalkylamine cores, either through direct trifluoroethylation of secondary amines or via a three-component coupling of primary amines, aldehydes and trifluoroacetic acid. A reduction of in situ-generated silyl ester species is proposed to account for the reductive selectivity observed.

Severe accident management (SAM), operator training and instrumentation capabilities - Summary and conclusions

International Nuclear Information System (INIS)

2002-01-01

The Workshop on Operator Training for Severe Accident Management (SAM) and Instrumentation Capabilities During Severe Accidents was organised in collaboration with Electricite de France (Service Etudes et Projets Thermiques et Nucleaires). There were 34 participants, representing thirteen OECD Member countries, the Russian Federation and the OECD/NEA. Almost half the participants represented utilities. The second largest group was regulatory authorities and their technical support organisations. Basically, the Workshop was a follow-up to the 1997 Second Specialist Meeting on Operator Aids for Severe Accident Management (SAMOA-2) [Reports NEA/CSNI/R(97)10 and 27] and to the 1992 Specialist Meeting on Instrumentation to Manage Severe Accidents [Reports NEA/CSNI/R(92)11 and (93)3]. It was aimed at sharing and comparing progress made and experience gained from these two meetings, emphasizing practical lessons learnt during training or incidents as well as feedback from instrumentation capability assessment. The objectives of the Workshop were therefore: - to exchange information on recent and current activities in the area of operator training for SAM, and lessons learnt during the management of real incidents ('operator' is defined hear as all personnel involved in SAM); - to compare capabilities and use of instrumentation available during severe accidents; - to monitor progress made; - to identify and discuss differences between approaches relevant to reactor safety; - and to make recommendations to the Working Group on the Analysis and Management of Accidents and the CSNI (GAMA). The Workshop was organised into five sessions: - 1: Introduction; - 2: Tools and Methods; - 3: Training Programmes and Experience; - 4: SAM Organisation Efficiency; - 5: Instrumentation Capabilities. It was concluded by a Panel and General Discussion. This report presents the summary and conclusions: the meeting confirmed that only limited information is needed for making required decisions

New procedure of selected biogenic amines determination in wine samples by HPLC

Energy Technology Data Exchange (ETDEWEB)

Piasta, Anna M.; Jastrzębska, Aneta, E-mail: aj@chem.uni.torun.pl; Krzemiński, Marek P.; Muzioł, Tadeusz M.; Szłyk, Edward

2014-06-27

Highlights: • We proposed new procedure for derivatization of biogenic amines. • The NMR and XRD analysis confirmed the purity and uniqueness of derivatives. • Concentration of biogenic amines in wine samples were analyzed by RP-HPLC. • Sample contamination and derivatization reactions interferences were minimized. - Abstract: A new procedure for determination of biogenic amines (BA): histamine, phenethylamine, tyramine and tryptamine, based on the derivatization reaction with 2-chloro-1,3-dinitro-5-(trifluoromethyl)-benzene (CNBF), is proposed. The amines derivatives with CNBF were isolated and characterized by X-ray crystallography and {sup 1}H, {sup 13}C, {sup 19}F NMR spectroscopy in solution. The novelty of the procedure is based on the pure and well-characterized products of the amines derivatization reaction. The method was applied for the simultaneous analysis of the above mentioned biogenic amines in wine samples by the reversed phase-high performance liquid chromatography. The procedure revealed correlation coefficients (R{sup 2}) between 0.9997 and 0.9999, and linear range: 0.10–9.00 mg L{sup −1} (histamine); 0.10–9.36 mg L{sup -1} (tyramine); 0.09–8.64 mg L{sup −1} (tryptamine) and 0.10–8.64 mg L{sup −1} (phenethylamine), whereas accuracy was 97%–102% (recovery test). Detection limit of biogenic amines in wine samples was 0.02–0.03 mg L{sup −1}, whereas quantification limit ranged 0.05–0.10 mg L{sup −1}. The variation coefficients for the analyzed amines ranged between 0.49% and 3.92%. Obtained BA derivatives enhanced separation the analytes on chromatograms due to the inhibition of hydrolysis reaction and the reduction of by-products formation.

Amine oxidase from lentil seedlings: energetic domains and effect of temperature on activity.

Science.gov (United States)

Moosavi-Nejad, S Z; Rezaei-Tavirani, M; Padiglia, A; Floris, G; Moosavi-Movahedi, A A

2001-07-01

Copper/TPQ amine oxidases from mammalian and plant sources have shown many differences in substrate specificity and molecular properties. In this work the activity of lentil seedling amine oxidase was followed at various temperatures in 100 mM potassium phosphate buffer, pH 7, using benzylamine as substrate. The discontinuous Arrhenius plot of lentil amine oxidase showed two distinct phases with a jump between them. Thermal denaturation of the enzyme, using differential scanning calorimetry under the same experimental conditions, showed a transition at the same temperature ranges in the absence of substrate, indicating the occurrence of conformational changes, with an enthalpy change of about 175.9 kJ/mole. The temperature-induced changes of the activity of lentil amine oxidase are compared with those of bovine serum amine oxidase (taken from the literature).

Deuterium exchange between hydrofluorocarbons and amines

International Nuclear Information System (INIS)

Hammond, W.B.; Bigeleisen, J.; Tuccio, S.A.

1983-01-01

The invention consists of a process for obtaining a compound enriched in deuterium which comprises the known method of exposing a gaseous hydrofluorocarbon to infrared laser radiation of a predetermined frequency to selectively cause a chemical reaction involving hydrofluorocarbon molecules containing deuterium without substantially affecting hydrofluorocarbon molecules not containing deuterium, thereby producing, as reaction products, a compound enriched in deuterium and hydrofluorocarbon depleted in deuterium; combined with a new method, which comprises enriching the deuterium content of the depleted hydrofluorocarbon by contacting the depleted hydrofluorocarbon with an alkali metal amide and an amine having a concentration of deuterium at least that which will yield an increase in deuterium concentration of the hydrofluorocarbon upon equilibration, whereby the amine becomes depleted in deuterium

Ruthenium-Catalyzed Aerobic Oxidation of Amines.

Science.gov (United States)

Ray, Ritwika; Hazari, Arijit Singha; Lahiri, Goutam Kumar; Maiti, Debabrata

2018-01-18

Amine oxidation is one of the fundamental reactions in organic synthesis as it leads to a variety of value-added products such as oximes, nitriles, imines, and amides among many others. These products comprise the key N-containing building blocks in the modern chemical industry, and such transformations, when achieved in the presence of molecular oxygen without using stoichiometric oxidants, are much preferred as they circumvent the production of unwanted wastes. In parallel, the versatility of ruthenium catalysts in various oxidative transformations is well-documented. Herein, this review focuses on aerobic oxidation of amines specifically by using ruthenium catalysts and highlights the major achievements in this direction and challenges that still need to be addressed. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Controlling noncovalent interactions between a lysine-rich α-helical peptide and self-assembled monolayers of alkanethiols on Au through functional group diversity

Energy Technology Data Exchange (ETDEWEB)

Raigoza, Annette F.; Onyirioha, Kristeen; Webb, Lauren J., E-mail: lwebb@cm.utexas.edu

2017-02-28

Highlights: • Functional variety in SAMs control covalent binding of proteins to surfaces. • Peptide density on Au(111) surfaces controlled by SAM functional groups. • Affinity between biomolecule and SAM surface follows a Langmuir isotherm. • Surface chemistry can mimic functional group diversity in proteins and peptides. - Abstract: Reliably attaching a structured biomolecule to an inorganic substrate would enable the preparation of surfaces that incorporate both biological and inorganic functions and structures. To this end, we have previously developed a procedure using the copper(I)-catalyzed click reaction to tether synthetic α-helical peptides carrying two alkyne groups to well-ordered alkanethiol self-assembled monolayers (SAM) on a Au(111) surface, in which the SAM is composed of a mixture of methyl and azide termination. Proteins, however, are composed of many diverse functional groups, and this composition directly effects protein structure, interactions, and reactivity. Here, we explore the utility of mixed SAMs with alternative terminating functional groups to tune and direct the reactivity of the surface through noncovalent peptide-surface interactions. We study both polar surfaces (OH-terminated) and charged surfaces (COOH- and NH{sub 3}-terminated, which are negatively and positively charged, respectively, under our reaction conditions). Surfaces were functionalized with a bipolar peptide composed of Lys and Leu residues that could express different interactions through either hydrophilic and/or charge (Lys) or hydrophobic (Leu) influences. X-ray photoelectron spectroscopy (XPS) and surface infrared spectroscopy were used to characterize surfaces at all stages of the peptide functionalization procedure. This strategy resulted in a high density of surface-bound α-helices without aggregation. Mixed SAMs that included a positively charged alkanethiol along with the azide-terminated thiol resulted in a more efficient reaction and better

Controlling noncovalent interactions between a lysine-rich α-helical peptide and self-assembled monolayers of alkanethiols on Au through functional group diversity

International Nuclear Information System (INIS)

Raigoza, Annette F.; Onyirioha, Kristeen; Webb, Lauren J.

2017-01-01

Highlights: • Functional variety in SAMs control covalent binding of proteins to surfaces. • Peptide density on Au(111) surfaces controlled by SAM functional groups. • Affinity between biomolecule and SAM surface follows a Langmuir isotherm. • Surface chemistry can mimic functional group diversity in proteins and peptides. - Abstract: Reliably attaching a structured biomolecule to an inorganic substrate would enable the preparation of surfaces that incorporate both biological and inorganic functions and structures. To this end, we have previously developed a procedure using the copper(I)-catalyzed click reaction to tether synthetic α-helical peptides carrying two alkyne groups to well-ordered alkanethiol self-assembled monolayers (SAM) on a Au(111) surface, in which the SAM is composed of a mixture of methyl and azide termination. Proteins, however, are composed of many diverse functional groups, and this composition directly effects protein structure, interactions, and reactivity. Here, we explore the utility of mixed SAMs with alternative terminating functional groups to tune and direct the reactivity of the surface through noncovalent peptide-surface interactions. We study both polar surfaces (OH-terminated) and charged surfaces (COOH- and NH_3-terminated, which are negatively and positively charged, respectively, under our reaction conditions). Surfaces were functionalized with a bipolar peptide composed of Lys and Leu residues that could express different interactions through either hydrophilic and/or charge (Lys) or hydrophobic (Leu) influences. X-ray photoelectron spectroscopy (XPS) and surface infrared spectroscopy were used to characterize surfaces at all stages of the peptide functionalization procedure. This strategy resulted in a high density of surface-bound α-helices without aggregation. Mixed SAMs that included a positively charged alkanethiol along with the azide-terminated thiol resulted in a more efficient reaction and better alignment

A Bioinspired Organocatalytic Cascade for the Selective Oxidation of Amines under Air.

Science.gov (United States)

Largeron, Martine; Fleury, Maurice-Bernard

2017-05-17

A bioinspired organocatalytic cascade reaction for the selective aerobic oxidative cross-coupling of primary amines to imines is described. This approach takes advantages of commercially available pyrogallol monomeric precursor to deliver low loadings of natural purpurogallin in situ, under air. This is further engaged in a catalytic process with the amine substrate affording, under single turnover, the active biomimetic quinonoid organocatalyst and the homocoupled imine intermediate, which is then converted into cross-coupled imine after dynamic transimination. This organocatalytic cascade inspired by both purpurogallin biosynthesis and copper amine oxidases allows the aerobic oxidation of non-activated primary amines that non-enzymatic organocatalysts were not able to accomplish alone. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

A rapid detection method for policy-sensitive amines real-time supervision.

Science.gov (United States)

Zhang, Haixu; Shu, Jinian; Yang, Bo; Zhang, Peng; Ma, Pengkun

2018-02-01

Many organic amines that comprise a benzene ring are policy-sensitive because of their toxicity and links to social harm. However, to date, detection of such compounds mainly relies on offline methods. This study proposes an online pptv (parts per trillion by volume) level of detection method for amines, using the recently-built vacuum ultraviolet photoionization mass spectrometer (VUV-PIMS) combined with a new doping technique. Thus, the dichloromethane doping-assisted photoionization mass spectra of aniline, benzylamine, phenethylamine, amphetamine, and their structural isomers were recorded. The dominant characteristic mass peaks for all amines are those afforded by protonated amines and the amino radical-loss. The signal intensities of the amines were enhanced by 60-130 times compared to those recorded without doping assistance. Under 10s detection time, the sensitivities of aniline and benzylamine in the gas phase were determined as 4.0 and 2.7 countspptv -1 , with limits of detection (LODs) of 36 and 22 pptv, respectively. Notably, the detection efficiency of this method can be tenfold better in future applications since the ion transmission efficiency of the mass spectrometer was intentionally reduced to ~ 10% in this study. Therefore, dichloromethane doping-assisted photoionization mass spectrometry has proven to be a highly promising on-line approach to amine detection in environmental and judicial supervision and shows great potential for application in the biological field. Copyright © 2017 Elsevier B.V. All rights reserved.

Dynamics of CO 2 Adsorption on Amine Adsorbents. 2. Insights Into Adsorbent Design

KAUST Repository

Bollini, Praveen

2012-11-21

Packed bed breakthrough experiments are reported for commercial zeolite 13X and 3-aminopropyl-functionalized SBA-15 silica materials with three different amine loadings. Mass and heat transfer dynamics for all four materials are modeled successfully. Amine adsorbents with open pores are found to exhibit faster mass diffusion rates compared to zeolite 13X. When amine loading is increased by coupling aminopropyl groups, premature breakthrough combined with a long tail is observed. Contrary to conventional physisorbants, finite heat losses to the column wall do not explain the long breakthrough tail. A rate model that accounts for heterogeneity in diffusion was found to accurately capture the breakthrough shape of the high loading material. Batch uptake measurements support the hypothesis that slow diffusion through the polymer phase is what hampers adsorption kinetics in the high amine loading adsorbent. The results emphasize the importance of designing materials that are not overloaded with amine sites, as excessive amine loadings can lead to depressed adsorption kinetics and premature column breakthrough. © 2012 American Chemical Society.

Reducing the energy penalty costs of postcombustion CCS systems with amine-storage.

Science.gov (United States)

Patiño-Echeverri, Dalia; Hoppock, David C

2012-01-17

Carbon capture and storage (CCS) can significantly reduce the amount of CO(2) emitted from coal-fired power plants but its operation significantly reduces the plant's net electrical output and decreases profits, especially during times of high electricity prices. An amine-based CCS system can be modified adding amine-storage to allow postponing 92% of all its energy consumption to times of lower electricity prices, and in this way has the potential to effectively reduce the cost of CO(2) capture by reducing the costs of the forgone electricity sales. However adding amine-storage to a CCS system implies a significant capital cost that will be outweighed by the price-arbitrage revenue only if the difference between low and high electricity prices is substantial. In this paper we find a threshold for the variability in electricity prices that make the benefits from electricity price arbitrage outweigh the capital costs of amine-storage. We then look at wholesale electricity markets in the Eastern Interconnect of the United States to determine profitability of amine-storage systems in this region. Using hourly electricity price data from years 2007 and 2008 we find that amine storage may be cost-effective in areas with high price variability.

Necrosis-Driven Systemic Immune Response Alters SAM Metabolism through the FOXO-GNMT Axis

Directory of Open Access Journals (Sweden)

Fumiaki Obata

2014-05-01

Full Text Available Sterile inflammation triggered by endogenous factors is thought to contribute to the pathogenesis of acute and chronic inflammatory diseases. Here, we demonstrate that apoptosis-deficient mutants spontaneously develop a necrosis-driven systemic immune response in Drosophila and provide an in vivo model for studying the organismal response to sterile inflammation. Metabolomic analysis of hemolymph from apoptosis-deficient mutants revealed increased sarcosine and reduced S-adenosyl-methionine (SAM levels due to glycine N-methyltransferase (Gnmt upregulation. We showed that Gnmt was elevated in response to Toll activation induced by the local necrosis of wing epidermal cells. Necrosis-driven inflammatory conditions induced dFoxO hyperactivation, leading to an energy-wasting phenotype. Gnmt was cell-autonomously upregulated by dFoxO in the fat body as a possible rheostat for controlling energy loss, which functioned during fasting as well as inflammatory conditions. We propose that the dFoxO-Gnmt axis is essential for the maintenance of organismal SAM metabolism and energy homeostasis.

ISOE EG-SAM interim report - Report on behalf of the Sub expert Group

International Nuclear Information System (INIS)

Harris, Willie; Miller, David W.; Djeffal, Salah; Anderson, Ellen; Couasnon, Olivier; Hagemeyer, Derek; Sovijarvi, Jukka; Amaral, Marcos A.; Tarzia, J.P.; Schmidt, Claudia; Fritioff, Karin; Kaulard, Joerg; Lance, Benoit; Fritioff, Karin; Schieber, Caroline; Hayashida, Yoshihisa; Doty, Rick

2014-01-01

During its November 2012 meeting, the expert group decided to develop an interim (preliminary) report before the end of 2013 (with a general perspective and discussion of specific severe accident management worker dose issues), and to finalize the report by organizing the international workshop of 2014 to address national experiences, which will be incorporated to the report. The work of the EG-SAM focuses on radiation protection management and organization, radiation protection training and exercises related to severe accident management, facility configuration and readiness, worker protection, radioactive materials, contamination controls and logistics and key lessons learned especially from the TMI, Chernobyl and Fukushima Dai-ichi accidents. This interim report was completed through intensive work of all Group members nominated by the ISOE, and was accomplished during EG-SAM meetings through 2012-2013. This document gathers the different presentations given by the sub expert groups in charge of each chapter of the report

Electrochemical characterization of a 1,8-octanedithiol self-assembled monolayer (ODT-SAM) on a Au(111) single crystal electrode

Energy Technology Data Exchange (ETDEWEB)

Garcia-Raya, Daniel; Madueno, Rafael; Sevilla, Jose Manuel; Blazquez, Manuel; Pineda, Teresa [Departamento de Quimica Fisica y Termodinamica Aplicada, Universidad de Cordoba, Campus de Rabanales, Cordoba (Spain)

2008-11-15

Recently, it has becoming increasingly important to control the organization of self-assembled monolayers (SAMs) of {omega}-functionalized thiols for its potential applications in the construction of more complex molecular architectures. In this paper, we report on the spontaneous formation of a SAM of octanedithiol (ODT) as a function of the modification time. Electrochemical techniques such as cyclic voltammetry, double layer capacitance and electrochemical impedance spectroscopy are used for the characterization of this monolayer. The increase in modification time brings about changes in the octanedithiol self-assembled monolayer (ODT-SAM) reductive desorption voltammograms that indicate an evolution toward a more ordered and compact monolayer. This trend has also been found by following the changes in the electron transfer processes of the redox probe K{sub 3}Fe(CN){sub 6}. In fact, the ODT-SAM formed at low-modification time does not significantly perturb the electrochemical response as it is typical of either a low coverage or of the presence of large defects in the layer. Upon increasing the modification time, the voltammograms of the redox probe adopt a sigmoidal shape indicating the existence of pinholes in the monolayer distributed as an array of microelectrodes. The surface coverage as well as the size and distribution of these pinholes have been determined by the impedance technique that gives a more reliable evaluation of these monolayer structural parameters. (author)

Tertiary-amine-containing thermo- and pH-sensitive hydrophilic ABA triblock copolymers: effect of different tertiary amines on thermally induced sol-gel transitions.

Science.gov (United States)

Henn, Daniel M; Wright, Roger A E; Woodcock, Jeremiah W; Hu, Bin; Zhao, Bin

2014-03-11

This Article reports on the synthesis of a series of well-defined, tertiary-amine-containing ABA triblock copolymers, composed of a poly(ethylene oxide) (PEO) central block and thermo- and pH-sensitive outer blocks, and the study of the effect of different tertiary amines on thermally induced sol-gel transition temperatures (T(sol-gel)) of their 10 wt % aqueous solutions. The doubly responsive ABA triblock copolymers were prepared from a difunctional PEO macroinitiator by atom transfer radical polymerization of methoxydi(ethylene glycol) methacrylate and ethoxydi(ethylene glycol) methacrylate at a feed molar ratio of 30:70 with ∼5 mol % of either N,N-diethylaminoethyl methacrylate (DEAEMA), N,N-diisopropylaminoethyl methacrylate, or N,N-di(n-butyl)aminoethyl methacrylate. The chain lengths of thermosensitive outer blocks and the molar contents of tertiary amines were very similar for all copolymers. Using rheological measurements, we determined the pH dependences of T(sol-gel) of 10 wt % aqueous solutions of these copolymers in a phosphate buffer. The T(sol-gel) versus pH curves of all polymers exhibited a sigmoidal shape. The T(sol-gel) increased with decreasing pH; the changes were small on both high and low pH sides. At a specific pH, the T(sol-gel) decreased with increasing the hydrophobicity of the tertiary amine, and upon decreasing pH the onset pH value for the T(sol-gel) to begin to increase noticeably was lower for the more hydrophobic tertiary amine-containing copolymer. In addition, we studied the effect of different tertiary amines on the release behavior of FITC-dextran from 10 wt % micellar gels in an acidic medium at 37 and 27 °C. The release profiles for three studied hydrogels at 37 °C were essentially the same, suggesting that the release was dominated by the diffusion of FITC-dextran. At 27 °C, the release was significantly faster for the DEAEMA-containing copolymer, indicating that both diffusion and gel dissolution contributed to the

The captain class : the hidden force that creates the world's greatest teams / Sam Walker

Trove (Australia)

Walker, Sam

2017-01-01

... it is. It's not the coach. It's not the star. It's not chemistry. It's not a strategy. It's something else entirely. Several years ago, Sam Walker set out to answer one of the most hotly debated questions in sports ...

Local coordination of Eu(III) in organic/inorganic amine functionalized hybrids

International Nuclear Information System (INIS)

Carlos, L.D.; Sa Ferreira, R.A.; Goncalves, M.C.; Zea Bermudez, V. de

2004-01-01

The sol-gel method was used to prepare two families of organic/inorganic hybrids incorporating europium triflate, classed as di-urethanesils and aminosils. A siliceous network to which short polyether chains are covalently bonded through urethane linkages, composes the di-urethanesil host. A siliceous network containing pendant amine terminated propyl chains, forms the aminosils. The xerogels were investigated by photoluminescence, particularly the local interaction between the Eu 3+ ions and the host matrix. The Eu 3+ local coordination was modelled in terms of a local-field perturbation representing the ion's nearest ligands interaction potential. While for the aminosils the Eu 3+ ions occupy one low-symmetry local site--crystal-field strength of ca. 760.5 cm -1 and 5 D 0 lifetime of 0.6-0.7 ms--two local Eu 3+ environments with distinct point symmetry group, 5 D 0 lifetimes (ca. 0.2-0.3 and 1.4-1.8 ms, respectively) and covalent nature--crystal-field strengths of ca. 540 and 740-780 cm -1 , respectively--were identified in the di-urethanesils

Mesoporous amine-bridged polysilsesquioxane for CO2 capture

KAUST Repository

Qi, Genggeng

2011-01-01

A novel class of amine-supported sorbents based on amine-bridged mesoporous polysilsesquioxane was developed via a simple one-pot sol-gel process. The new sorbent allows the incorporation of a large amount of active groups without sacrificing surface area or pore volume available for CO2 capture, leading to a CO2 capture capacity of 3.2 mmol g−1 under simulated flue gas conditions. The sorbent is readily regenerated at 100°C and exhibits good stability over repetitive adsorption-desorption cycling.

Biogenic Amines as Quality Marker in Organic and Fair-Trade Cocoa-Based Products

Directory of Open Access Journals (Sweden)

Donatella Restuccia

2016-08-01

Full Text Available In this study, the quantitative determination of eight biogenic amines (cadaverine, serotonin, histamine, spermidine, spermine, tyramine, putrescine and β-phenylethylamine by an liquid chromatography method with evaporative light scattering detection was performed. The analysis of several samples of conventional, organic and fair trade cocoa-derivatives showed that organic and fair trade samples always contain much lower amine concentrations in comparison with their conventional counterparts, supporting the idea that biogenic amines can be regarded as cocoa quality markers. Irrespective of the kind of sample, results also showed that the most abundant amines were histamine, tyramine, spermidine, putrescine and spermine while β-phenylethylamine, cadaverine and serotonine have been found more rarely, all the amines never reaching dangerous amounts for consumer health. With the aim to confirm the experimental results, clustering analysis was performed on samples and instrumental results using principal component analysis.

Efficient degradation of sulfamethazine in simulated and real wastewater at slightly basic pH values using Co-SAM-SCS /H2O2 Fenton-like system.

Science.gov (United States)

Cheng, Min; Zeng, Guangming; Huang, Danlian; Lai, Cui; Liu, Yang; Zhang, Chen; Wan, Jia; Hu, Liang; Zhou, Chengyun; Xiong, Weiping

2018-07-01

The presence of antibiotics in aquatic environments has attracted global concern. Fenton process is an attractive yet challenging method for antibiotics degradation, especially when such a reaction can be conducted at neutral pH values. In this study, a novel composite Fe/Co catalyst was synthesized via the modification of steel converter slag (SCS) by salicylic acid-methanol (SAM) and cobalt nitrate (Co(NO 3 ) 2 ). The catalysts were characterized by N 2 -Brunauer-Emmett-Teller (BET), X-ray diffraction (XRD), Fourier transform infrared (FT-IR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). The results indicated that the Co-SAM-SCS/H 2 O 2 Fenton-like system was very effective for sulfamethazine (SMZ) degradation at a wide pH range. At initial pH of 7.0, the degradation rate of SMZ in Co-SAM-SCS/H 2 O 2 system was 2.48, 3.20, 6.18, and 16.21 times of that in Fe-SAM-SCS/H 2 O 2 , SAM-SCS/H 2 O 2 , Co(NO 3 ) 2 /H 2 O 2 and SCS/H 2 O 2 system, respectively. The preliminary analysis suggested that high surface area of Co-SAM-SCS sample and synergistic effect between introduced Co and SAM-SCS are responsible for the efficient catalytic activity. During the degradation, three main intermediates were identified by high performance liquid chromatography-mass spectrometry (HPLC-MS) analysis. Based on this, a possible degradation pathway was proposed. The SEM images, XRD patterns and XPS spectra before and after the reactions demonstrate that the crystal and chemical structure of Co-SAM-SCS after five cycles are almost unchanged. Besides, the Co-SAM-SCS presented low iron and cobalt leaching (0.17 mg/L and 2.36 mg/L, respectively). The studied Fenton-like process also showed high degradation of SMZ in river water and municipal wastewater. The progress will bring valuable insights to develop high-performance heterogeneous Fenton-like catalysts for environmental remediation. Copyright © 2018

Molecular Evolution and Functional Divergence of Trace Amine-Associated Receptors.

Directory of Open Access Journals (Sweden)

Seong-Il Eyun

Full Text Available Trace amine-associated receptors (TAARs are a member of the G-protein-coupled receptor superfamily and are known to be expressed in olfactory sensory neurons. A limited number of molecular evolutionary studies have been done for TAARs so far. To elucidate how lineage-specific evolution contributed to their functional divergence, we examined 30 metazoan genomes. In total, 493 TAAR gene candidates (including 84 pseudogenes were identified from 26 vertebrate genomes. TAARs were not identified from non-vertebrate genomes. An ancestral-type TAAR-like gene appeared to have emerged in lamprey. We found four therian-specific TAAR subfamilies (one eutherian-specific and three metatherian-specific in addition to previously known nine subfamilies. Many species-specific TAAR gene duplications and losses contributed to a large variation of TAAR gene numbers among mammals, ranging from 0 in dolphin to 26 in flying fox. TAARs are classified into two groups based on binding preferences for primary or tertiary amines as well as their sequence similarities. Primary amine-detecting TAARs (TAAR1-4 have emerged earlier, generally have single-copy orthologs (very few duplication or loss, and have evolved under strong functional constraints. In contrast, tertiary amine-detecting TAARs (TAAR5-9 have emerged more recently and the majority of them experienced higher rates of gene duplications. Protein members that belong to the tertiary amine-detecting TAAR group also showed the patterns of positive selection especially in the area surrounding the ligand-binding pocket, which could have affected ligand-binding activities and specificities. Expansions of the tertiary amine-detecting TAAR gene family may have played important roles in terrestrial adaptations of therian mammals. Molecular evolution of the TAAR gene family appears to be governed by a complex, species-specific, interplay between environmental and evolutionary factors.

The distribution and adsorption behavior of aliphatic amines in marine and lacustrine sediments

Science.gov (United States)

Wang, Xu-chen; Lee, Cindy

1990-10-01

The methylated amines—monomethyl-, dimethyl-, and trimethyl amine (MMA, DMA, TMA)—are commonly found in aquatic environments, apparently as a result of decomposition processes. Adsorption of these amines to clay minerals and organic matter significantly influences their distribution in sediments. Laboratory measurements using 14C-radiolabelled amines and application of a linear partitioning model resulted in calculated adsorption coefficients of 2.4-4.7 (MMA), 3.3 (DMA), and 3.3-4.1 (TMA). Further studies showed that adsorption of amines is influenced by salinity of the porewaters, and clay mineral and organic matter content of the sediment solid phase. Concentrations of monomethyl- and dimethyl amine were measured in the porewaters and the solid phase of sediment samples collected from Flax Pond and Lake Ronkonkoma (NY), Long Island Sound, and the coastal Peru upwelling area. These two amines were present in all sediments investigated. A clear seasonal increase in the solid-phase concentration of MMA and DMA in Flax Pond sediments was likely related to the annual senescence of salt marsh grasses, either directly as a source of these compounds or indirectly by providing additional exchange capacity to the sediments. The distribution of amines in the solid and dissolved phases observed in all sediments investigated suggests that the distribution of these compounds results from a balance among production, decomposition, and adsorption processes.

A protocol for amide bond formation with electron deficient amines and sterically hindered substrates

DEFF Research Database (Denmark)

Due-Hansen, Maria E; Pandey, Sunil K; Christiansen, Elisabeth

2016-01-01

A protocol for amide coupling by in situ formation of acyl fluorides and reaction with amines at elevated temperature has been developed and found to be efficient for coupling of sterically hindered substrates and electron deficient amines where standard methods failed.......A protocol for amide coupling by in situ formation of acyl fluorides and reaction with amines at elevated temperature has been developed and found to be efficient for coupling of sterically hindered substrates and electron deficient amines where standard methods failed....

In Situ Analysis of Martian Regolith with the SAM Experiment During the First Mars Year of the MSL Mission: Identification of Organic Molecules by Gas Chromatography from Laboratory Measurements

Science.gov (United States)

Millan, M.; Szopa, C.; Buch, A.; Coll, P.; Glavin, D. P.; Freissinet, C.; Navarro-Gonzalez, R.; Francois, P.; Coscia, D.; Bonnet, J. Y.;

Amine metabolism in the human brain : evaluation of the probenecid test

NARCIS (Netherlands)

Korf, Jacob

1971-01-01

There are indirect indications, that biogenic amines in the brain are concerned with pathological states such as depression (serotonin, 5HT and noradrenaline, NA) and Parkonsonism (dopamine, DA). These indications were obtained from measurements of amines and their metabolites in pe - ripheral

CO_2 capture by amine-functionalized nanoporous materials: A review

International Nuclear Information System (INIS)

Chen, Chao; Kim, Jun; Ahn, Wha-Seung

2014-01-01

Amine-functionalized nanoporous materials can be prepared by the incorporation of diverse organic amine moieties into the pore structures of a range of support materials, such as mesoporous silica and alumina, zeolite, carbon and metal organic frameworks (MOFs), either by direct functionalization or post-synthesis through physical impregnation or grafting. These hybrid materials have great potential for practical applications, such as dry adsorbents for postcombustion CO_2 capture, owing to their high CO_2 capture capacity, high capture selectivity towards CO_2 compared to other gases, and excellent stability. This paper summarizes the preparation methods and CO_2 capture performance based on the equilibrium CO_2 uptake of a range of amine-functionalized nanoporous materials

Vapour pressure and enthalpy of vaporization of aliphatic poly-amines

International Nuclear Information System (INIS)

Efimova, Anastasia A.; Emel'yanenko, Vladimir N.; Verevkin, Sergey P.; Chernyak, Yury

2010-01-01

Molar enthalpies of vaporization of aliphatic poly-amines: 1,4-dimethylpiperazine [106-58-1], 1-(2-aminoethyl)-piperazine, [140-31-8], 1-(2-aminoethyl)-4-methyl-piperazine [934-98-5], and triethylenetetramine [112-24-3] were obtained from the temperature dependence of the vapour pressure measured by the transpiration method. A large number of the primary experimental results on temperature dependences of vapour pressures of the parent compounds have been collected from the literature and have been treated uniformly in order to derive vaporization enthalpies of poly-amines at the reference temperature 298.15 K. An internal consistency check was performed on enthalpy of vaporization values for poly-amines studied in this work.

Effect of immobilized amine density on cadmium(II) adsorption capacities for ethanediamine-modified magnetic poly-(glycidyl methacrylate) microspheres

Energy Technology Data Exchange (ETDEWEB)

Dong, Tingting [Key Laboratory of Green Process and Engineering, State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Yang, Liangrong, E-mail: lryang@ipe.ac.cn [Key Laboratory of Green Process and Engineering, State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190 (China); Pan, Feng; Xing, Huifang; Wang, Li; Yu, Jiemiao [Key Laboratory of Green Process and Engineering, State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190 (China); Qu, Hongnan [Key Laboratory of Green Process and Engineering, State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101 (China); Rong, Meng [Key Laboratory of Green Process and Engineering, State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Liu, Huizhou, E-mail: hzliu@ipe.ac.cn [Key Laboratory of Green Process and Engineering, State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190 (China)

2017-04-01

A series of ethanediamine (EDA) – modified magnetic poly-(glycidyl methacrylate) (m-PGMA-EDA)microspheres with different amine density were synthesized and their cadmium saturation adsorption capacities were examined. The results showed that the cadmium saturation adsorption capacity increased with the immobilized amine density. However, they did not show strong positive linear correlation in the whole range of amine density examined. The molar ratio of amine groups to the adsorbed cadmium decreased with the increase of amine density and eventually reached a minimum value about 4. It suggested that low immobilized amine density led to low coordination efficiency of the amine. It is hypothesized that the immobilized amine groups needed to be physically close enough to form stable amine-metal complex. When the amine density reached to a critical value 1.25 m mol m{sup −2}, stable amine-cadmium complex (4:1 N/Cd) was proposed to form. To illustrate the coordination mechanism (structure and number) of amine and Cd, FT-IR spectra of m-PGMA-EDA and m-PGMA-EDA-Cd , and X-ray photoelectron spectroscopy (XPS) of PGMA–EDA and PGMA-EDA-Cd were examined and analyzed. - Highlights: • A series of magnetic poly-(glycidyl methacrylate) (m-PGMA-EDA)microspheres with different amine density were synthesized and their cadmium saturation adsorption capacities were examined. • The molar ratio of amine groups to adsorbed cadmium decreased with the increase of amine density and eventually reached a minimum value about 4. • when the amine density reached high enough, 4:1 N/Cd complex was proposed to form, and the hydroxyl also participated in the chelating with Cd.

Homologation of methanol catalyzed by transition metal complexes in the presence of tertiary amines

Energy Technology Data Exchange (ETDEWEB)

Tanaka, Masato; Ogata, Ikuei

1987-12-18

This paper describes the homologation of methanol by transition metal carbonyl catalysts in the presence of tertiary amines. Methanol was reacted with amine using a catalyst at 180/sup 0/C under 100 atm in the atmosphere of CO and H/sub 2/ mixed at the ratio of 4 in an autoclave. The reaction activities and selectivities of ethanol using iron carbonyl and Co carbonyl catalysts are superior. Only the iron catalyst was used hereafter because phosphine is required for the latter catalyst. N-methyl- piperidine, a cyclic amine, is superior to the other amines. The selectivity of ethanol is higher under higher partial pressure of H/sub 2/ and lower partial pressure of CO. The conversion rate is optimum at 180/sup 0/ and it goes down with increasing the temperature from it. Since the selectivity is markedly decreased with increasing amine, the reaction activity must be balanced with the amount of amine. The presence of solvent affects it. (3 figs, 6 tabs, 15 refs)

A Study to Evaluate the Organization and the Operating Procedures of the Patient Assistance Function at Brooke Army Medical Center, Fort Sam Houston, Texas

Science.gov (United States)

1979-08-01

15 March 1979. 59Interview with Wendy L. Farace , Head Nurse, Obstetrics/Gynecology Clinic, Brooke Army Medical Center, Fort Sam Houston, Texas, 8...6 February 1979. Farace , Wendy L. Head Nurse, Obstetrica/Gynecology Clinic, Brooke Army Medical Center, Fort Sam Houston, Texas. Interview, 8 January

Effect of aromatic SAMs molecules on graphene/silicon schottky diode performance

OpenAIRE

Yağmurcukardeş, Nesli; Aydın, Hasan; Can, Mustafa; Yanılmaz, Alper; Mermer, Ömer; Okur, Salih; Selamet, Yusuf

2016-01-01

Au/n-Si/Graphene/Au Schottky diodes were fabricated by transferring atmospheric pressure chemical vapor deposited (APCVD) graphene on silicon substrates. Graphene/n-Si interface properties were improved by using 5-[(3-methylphenyl)(phenyl) amino]isophthalic acid (MePIFA) and 5-(diphenyl)amino]isophthalic acid (DPIFA) aromatic self-assembled monolayer (SAM) molecules. The surface morphologies of modified and non-modified films were investigated by atomic force microscopy and scanning electron ...

Inhibitory Effects of Spices on Biogenic Amine Accumulation during Fish Sauce Fermentation.

Science.gov (United States)

Zhou, Xuxia; Qiu, Mengting; Zhao, Dandan; Lu, Fei; Ding, Yuting

2016-04-01

The presence of high levels of biogenic amines is detrimental to the quality and safety of fish sauce. This study investigated the effects of ethanol extracts of spices, including garlic, ginger, cinnamon, and star anise extracts, in reducing the accumulation of biogenic amines during fish sauce fermentation. The concentrations of biogenic amines, which include histamine, putrescine, tyramine, and spermidine, all increased during fish sauce fermentation. When compared with the samples without spices, the garlic and star anise extracts significantly reduced these increases. The greatest inhibitory effect was observed for the garlic ethanolic extracts. When compared with controls, the histamine, putrescine, tyramine, and spermidine contents and the overall biogenic amine levels of the garlic extract-treated samples were reduced by 30.49%, 17.65%, 26.03%, 37.20%, and 27.17%, respectively. The garlic, cinnamon, and star anise extracts showed significant inhibitory effects on aerobic bacteria counts. Furthermore, the garlic and star anise extracts showed antimicrobial activity against amine producers. These findings may be helpful for enhancing the safety of fish sauce. © 2016 Institute of Food Technologists®

Environmentally friendly chemoselective oxidation of primary aliphatic amines by using a biomimetic electrocatalytic system.

Science.gov (United States)

Largeron, Martine; Chiaroni, Angèle; Fleury, Maurice-Bernard

2008-01-01

Environmentally friendly oxidation of primary aliphatic amines to imines has been successfully achieved, under metal-free conditions, by the use of diverse electrogenerated o-azaquinone mediators. High catalytic performance, together with high chemoselectivity, were observed with electron-poor o-azaquinone catalysts generated from 2-aminoresorcinol derivatives. Similar to copper amine oxidase enzymes, these mediators exhibited lower reactivity toward alpha-branched primary amines and no reactivity toward secondary amines. In the case of 3,4-aminophenol derivatives lacking a 2-hydroxy group, the generated o-azaquinone species failed to catalyze the oxidation of the amine to the corresponding imine. Further mechanistic considerations allowed a rationalization of the crucial role of the 2-hydroxy group in converting a catalytically inert species into a highly effective biomimetic catalyst.

Structure-Activity Relationships for Rates of Aromatic Amine Oxidation by Manganese Dioxide.

Science.gov (United States)

Salter-Blanc, Alexandra J; Bylaska, Eric J; Lyon, Molly A; Ness, Stuart C; Tratnyek, Paul G

2016-05-17

New energetic compounds are designed to minimize their potential environmental impacts, which includes their transformation and the fate and effects of their transformation products. The nitro groups of energetic compounds are readily reduced to amines, and the resulting aromatic amines are subject to oxidation and coupling reactions. Manganese dioxide (MnO2) is a common environmental oxidant and model system for kinetic studies of aromatic amine oxidation. In this study, a training set of new and previously reported kinetic data for the oxidation of model and energetic-derived aromatic amines was assembled and subjected to correlation analysis against descriptor variables that ranged from general purpose [Hammett σ constants (σ(-)), pKas of the amines, and energies of the highest occupied molecular orbital (EHOMO)] to specific for the likely rate-limiting step [one-electron oxidation potentials (Eox)]. The selection of calculated descriptors (pKa, EHOMO, and Eox) was based on validation with experimental data. All of the correlations gave satisfactory quantitative structure-activity relationships (QSARs), but they improved with the specificity of the descriptor. The scope of correlation analysis was extended beyond MnO2 to include literature data on aromatic amine oxidation by other environmentally relevant oxidants (ozone, chlorine dioxide, and phosphate and carbonate radicals) by correlating relative rate constants (normalized to 4-chloroaniline) to EHOMO (calculated with a modest level of theory).