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One Step (one + step)
Kinds of One Step Selected AbstractsMultifunctional Integrated Platforms: Fabrication of Advanced Functional Devices Combining Soft Chemistry with X-ray Lithography in One Step (Adv. Mater.ADVANCED MATERIALS, Issue 48 200948/2009) Combining bottom-up sol,gel assembly with micro- and nanofabrication offers a simple and fast route to develop multifunctional integrated platforms, from microfluidics to microarrays, allowing the chemistry and geometry to be tailored to the application, as reported by Paolo Falcaro, Plinio Innocenzi, and co-workers on p. 4932. The inside cover illustrates different patterns of functionalized surfaces. The background is an example of highly controlled microfluidic interface fabricated combining deep X-rays lithography with sol,gel syntheses. [source] Fabrication of Advanced Functional Devices Combining Soft Chemistry with X-ray Lithography in One StepADVANCED MATERIALS, Issue 48 2009Paolo Falcaro Deep X-ray lithography combined with sol,gel techniques offers facile fabrication of controlled patterned films. Using sol,gel, different functional properties can be induced; deep X-ray lithography alters the functionality in the exposed regions. Miniaturized devices based on local property changes are easily fabricated: this technique requires no resist, enabling direct patterning of films in a one-step lithographic process. [source] ChemInform Abstract: Construction of Three Contiguous Tertiary Stereocenters from Aziridines in One Step.CHEMINFORM, Issue 13 2008Evgeniy V. Blyumin Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] A Versatile Method for the Synthesis of Benzimidazoles from o-Nitroanilines and Aldehydes in One Step via a Reductive Cyclization.CHEMINFORM, Issue 21 2005Donglai Yang Abstract For Abstract see ChemInform Abstract in Full Text. [source] Use tests: ROAT (repeated open application test)/PUT (provocative use test): an overviewCONTACT DERMATITIS, Issue 1 2000Tokio Nakada As one step in defining the clinical relevance of exposure to an allergen identified with patch testing, use tests (provocative use test (PUT), and repeated open application test (ROAT)) have been used. In 1/2 of the cases of seemingly reliable patch tests, use tests are negative, suggesting that the patient's biologic threshold of response had not been reached with open application dosing. Dramatic differences exist in regional skin reactivity and percutaneous penetration. Negative results of use tests on normal skin may become positive on diseased skin. To refine this assay further, more controlled observations and analysis of reaction differences between normal and damaged skin, and among regional anatomic sites might be performed. In addition, we require a standardized measurement for the results. Use testing has significant potential in refinement of the evidence-based diagnosis of clinical relevance. However, for general validation, we should fill the deficiencies described above. [source] Focused proteomics: Monoclonal antibody-based isolation of the oxidative phosphorylation machinery and detection of phosphoproteins using a fluorescent phosphoprotein gel stainELECTROPHORESIS, Issue 15 2004James Murray Abstract We have raised monoclonal antibodies capable of immunocapturing all five complexes involved in oxidative phosphorylation for evaluating their post-translational modifications. Complex I (NADH dehydrogenase), complex II (succinate dehydrogenase), complex III (cytochrome c reductase), complex IV (cytochrome c oxidase), and complex V (F1F0 ATP synthase) from bovine heart mitochondria were obtained in good yield from small amounts of tissue in more than 90% purity in one step. The composition and purity of the complexes was evaluated by Western blotting using monoclonal antibodies against individual subunits of the five complexes. In this first study, the phosphorylation state of the proteins without inducing phosphorylation or dephosphorylation was identified by using the novel Pro-Q Diamond phosphoprotein gel stain. The major phosphorylated components were the same as described before in sucrose gradient enriched complexes. In addition a few additional potential phosphoproteins were observed. Since the described monoclonal antibodies show cross reactivity to human proteins, this procedure will be a fast and efficient way of studying post-translational modifications in control and patient samples using only small amounts of tissue. [source] Solvothermal Synthesis, Crystal Structures, and Properties of New Selenidoantimonates [Ln(en)4(SbSe4)] (Ln = La, Nd) and [Sm(en)4]SbSe4·0.5en: The First Example of an SbSe43, Anion Acting as a Ligand to a Lanthanide ComplexEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 14 2006Ding-Xian Jia Abstract Three new lanthanide selenidoantimonates [Ln(en)4(SbSe4)] [Ln = La (1), Nd (2)] and [Sm(en)4]SbSe4·0.5en (3) (en = ethylenediamine) were first synthesized by treating LnCl3, Sb, and Se in a stoichiometric ratio with en under mild solvothermal conditions. Compounds 1 and 2 are isostructural. The Ln3+ ion has a nine-coordinate environment involving eight N atoms from four en ligands and one Se atom from the SbSe43, anion forming a distorted bicapped pentagonal bipyramid. [La(en)4(SbSe4)] and [Nd(en)4(SbSe4)] are the first examples of solvothermally synthesized selenidoantimonates with an SbSe43, anion acting as a ligand in a lanthanide complex. The crystal structure of 3 contains an isolated bicapped trigonal-prismatic coordinated [Sm(en)4]3+ cation, a tetrahedral SbSe43, anion, and half a free en molecule in its asymmetric unit. The bandgaps of 2.22 eV for 1, 2.33 eV for 2, and 2.54 eV for 3 have been derived from optical absorption spectra. Compound 1 loses the en ligands in one step, whereas compound 2 loses them in two steps. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source] The RuO4 -Catalyzed Ketohydroxylation, Part II:A Regio-, Chemo- and Stereoselectivity StudyEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 9 2005Bernd Plietker Abstract The direct RuO4 -catalyzed ketohydroxylation of olefins is a new and convenient method for the preparation of a wide range of symmetrical and unsymmetrical ,-hydroxy ketones. Since reactions in which two different functional groups are introduced in one step always involve regio-, chemo- and stereoselectivity issues, this paper gives a full account of investigations of various selectivity aspects in the ketohydroxylation. Stereoselectivity issues were examined in the final part of the present report. The Kishi rules, known from OsO4 -catalyzed dihydroxylations, are found to be valid for the RuO4 -catalyzed ketohydroxylation and lead to moderate to good diastereomeric ratios in the oxidation of olefins possessing an allylic center of chirality. Furthermore, competition experiments between different substituted olefins led to a reactivity profile applicable to the prediction of which is the most reactive of different C=C double bonds present in a molecule. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005) [source] 3-Tocopherylisoxazolines by [2+3] CycloadditionEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 6 2004Thomas Rosenau Abstract New isoxazoline derivatives of ,-tocopherol (1), the main component of vitamin E, were synthesized in a facile, two-step sequence consisting of nitration followed by 1,3-dipolar cycloaddition. 5-Nitromethyl-,-tocopheryl acetate (3), obtained from the cheap ,-tocopheryl acetate (2) by direct nitration in one step, acted as the nitrile oxide precursor in the reaction with various alkenes. The facile conversion proceeded in the presence of equimolar amounts of PhNCO and catalytic amounts of triethylamine. The NMR spectra of the product isoxazolines 5,13, showing strongly temperature-dependent resonances of the 4,,-CH, 4-CH2 and the acetyl group, are discussed, and the crystal structures of model compounds containing a methyl group instead of the isoprenoid side chain are presented. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004) [source] Numerical modelling of fatigue crack initiation and growth of martensitic steelsFATIGUE & FRACTURE OF ENGINEERING MATERIALS AND STRUCTURES, Issue 11 2010N. JEZERNIK ABSTRACT This paper presents a numerical simulation of micro-crack initiation that is based on Tanaka-Mura micro-crack nucleation model. Three improvements were added to this model. First, multiple slip bands where micro-cracks may occur are used in each grain. Second improvement deals with micro-crack coalescence by extending existing micro-cracks along grain boundaries and connecting them into a macro-crack. The third improvement handles segmented micro-crack generation, where a micro-crack is not nucleated in one step like in Tanaka-Mura model, but is instead generated in multiple steps. High cycle fatigue testing was also performed and showed reasonably good correlation of proposed model to experimental results. Because numerical model was directed at simulating fatigue properties of thermally cut steel, edge properties of test specimens were additionally inspected in terms of surface roughness and micro-structural properties. [source] Enhancement of Interconnectivity in the Channels of Pentacene Thin-Film Transistors and Its Effect on Field-Effect Mobility,ADVANCED FUNCTIONAL MATERIALS, Issue 14 2006S. Lee Abstract With the aim of improving the field-effect mobility of transistors by promoting the interconnectivity of the grains in pentacene thin films, deposition conditions of the pentacene molecules using one-step (total thickness of layer 50,nm: 0.1,Å,s,1) and two-step (first layer 10,nm: 0.1,Å,s,1, second layer 40,nm: 4.0,Å,s,1) depositions are controlled. Significantly, it is found that the continuities of the pentacene thin films vary with the deposition conditions of the pentacene molecules. Specifically, a smaller number of voids is observed at the interface for the two-step deposition, which results in field-effect mobilities as high as 1.2,cm2,V,1,s,1; these are higher by more than a factor of two than those of the pentacene films deposited in one step. This remarkable increase in field-effect mobility is due in particular to the interconnectivity of the pentacene grains near the insulator substrate. [source] Executive functioning by 18-24-month-old children: effects of inhibition, working memory demands and narrative in a novel detour-reaching taskINFANT AND CHILD DEVELOPMENT, Issue 5 2006Nicola McGuigan Abstract Infants can inhibit a prepotent but wrong action towards a goal in order to perform a causal means-action. It is not clear, however, whether infants can perform an arbitrary means-action while inhibiting a prepotent response. In four experiments, we explore this executive functioning in 18,24-month-old children. The working memory and inhibition demands in a novel means-end problem were systematically varied in terms of the type and combination of means-action(s) (causal or arbitrary) contained within the task, the number of means-actions (1 or 2), the goal visual availability and whether the task was accompanied by a narrative. Experiments 1 and 2 showed that children performed tasks that contained causal as opposed to arbitrary information more accurately; accuracy was also higher in tasks containing only one step. Experiment 2 also demonstrated that performance in the arbitrary task improved significantly when all sources of prepotency were removed. In Experiment 3, task performance improved when the two means-actions were intelligibly linked to the task goal. Experiment 4 demonstrated that the use of a narrative that provided a meaningful (non-causal) link between the two means-actions also improved children's performance by assisting their working memory in the generation of a rationale. Findings provide an initial account of executive functioning in the months that bring the end of infancy. Copyright © 2006 John Wiley & Sons, Ltd. [source] Large-scale topology optimization using preconditioned Krylov subspace methods with recyclingINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 12 2007Shun Wang Abstract The computational bottleneck of topology optimization is the solution of a large number of linear systems arising in the finite element analysis. We propose fast iterative solvers for large three-dimensional topology optimization problems to address this problem. Since the linear systems in the sequence of optimization steps change slowly from one step to the next, we can significantly reduce the number of iterations and the runtime of the linear solver by recycling selected search spaces from previous linear systems. In addition, we introduce a MINRES (minimum residual method) version with recycling (and a short-term recurrence) to make recycling more efficient for symmetric problems. Furthermore, we discuss preconditioning to ensure fast convergence. We show that a proper rescaling of the linear systems reduces the huge condition numbers that typically occur in topology optimization to roughly those arising for a problem with constant density. We demonstrate the effectiveness of our solvers by solving a topology optimization problem with more than a million unknowns on a fast PC. Copyright © 2006 John Wiley & Sons, Ltd. [source] Kinetics of base hydrolysis of ,-amino acid esters catalyzed by the copper(II) complex of N,N,N,,N,-tetramethylethylenediamine (Me4en)INTERNATIONAL JOURNAL OF CHEMICAL KINETICS, Issue 12 2006Mahmoud M. A. Mohamed The kinetics of base hydrolysis of glycine-, histidine-, and methionine methyl esters in the presence of [Cu-Me4en]2+ complex is studied in aqueous solutions and in dioxane,water solutions of different compositions at T = 25°C and I = 0.1 mol dm,1. The kinetics of base hydrolysis of glycine and methionine methyl esters is studied at different temperatures. The kinetic data fits assuming that the hydrolysis proceeds in one step. The activation parameters for the base hydrolysis of the complexes are evaluated. © 2006 Wiley Periodicals, Inc. Int J Chem Kinet 38: 737,745, 2006 [source] Petri net model of protocol conversion for CTF service: its universal coupling criteria and property analysisINTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 5 2007Xiaomin Zhu Abstract Protocol conversion is a critical issue requiring much research attention. In this paper, the protocol conversion methodology proposed originally by Green is extended with the Petri nets theory to study application layer protocol conversion among more than two interfaces. The click-to-fax (CTF) service based on the Internet intelligent network (IIN) model is taken as an example to illustrate the extended part. A two-step Petri net modelling method is proposed, which is easier compared to constructing the overall model directly in just one step. Universal coupling criteria of Petri net model of protocol conversion (PNPC) are abstracted. The PNPC of CTF service is analysed using analytical techniques of Petri nets, which are proved to be effective in finding and eliminating potential bugs. The necessity of the concept of service layer is also emphasized. Copyright © 2006 John Wiley & Sons, Ltd. [source] Use of image analysis techniques for objective quantification of the efficacy of different hair removal methodsINTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Issue 2 2007S. Bielfeldt In the field of consumer-used cosmetics for hair removal and hair growth reduction, there is a need for improved quantitative methods to enable the evaluation of efficacy and claim support. Optimized study designs and investigated endpoints are lacking to compare the efficacy of standard methods, like shaving or plucking, with new methods and products, such as depilating instruments or hair-growth-reducing cosmetics. Non-invasive image analysis, using a high-performance microscope combined with an optimized image analysis tool, was investigated to assess hair growth. In one step, high-resolution macrophotographs of the legs of female volunteers after shaving and plucking with cold wax were compared to observe short-term hair regrowth. In a second step, images obtained after plucking with cold wax were taken over a long-term period to assess the time, after which depilated hairs reappeared on the skin surface. Using image analysis, parameters like hair length, hair width, and hair projection area were investigated. The projection area was found to be the parameter most independent of possible image artifacts such as irregularities in skin or low contrast due to hair color. Therefore, the hair projection area was the most appropriate parameter to determine the time of hair regrowth. This point of time is suitable to assess the efficacy of different hair removal methods or hair growth reduction treatments by comparing the endpoint after use of the hair removal method to be investigated to the endpoint after simple shaving. The closeness of hair removal and visible signs of skin irritation can be assessed as additional quantitative parameters from the same images. Discomfort and pain rating by the volunteers complete the set of parameters, which are required to benchmark a new hair removal method or hair-growth-reduction treatment. Image analysis combined with high-resolution imaging techniques is a powerful tool to objectively assess parameters like hair length, hair width, and projection area. To achieve reliable data and to reduce well known image-analysis artifacts, it was important to optimize the technical equipment for use on human skin and to improve image analysis by adaptation of the image-processing procedure to the different skin characteristics of individuals, like skin color, hair color, and skin structure. [source] Observation of Field-Effect Transistor Behavior at Self-Organized Interfaces,ADVANCED MATERIALS, Issue 18 2004L.-L. Chua Ultrathin, conformal semiconductor, dielectric bilayers can be fabricated in one step by self-organization (see Figure), without exposing the critical interface to ambient contamination. Low-voltage polymer field-effect transistors using a fluorene,triarylamine copolymer as the p-channel semiconductor and 40,60 nm thick crosslinked bisbenzocyclobutene derivative as the gate dielectric are shown to be robust and reproducible. [source] Second Generation CaSH (Camphor Sulfonyl Hydrazine) Organocatalysis.ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 13 2010Alder Reactions, Asymmetric Diels, Isolation of the Catalytic Intermediate Abstract In one step, the well known chiral auxiliary, Oppolzer's camphor sultam, is turned into the new generation camphor sulfonyl hydrazine (CaSH II) organocatalyst. With the primary hydrazine functionality external to the tricyclic structure, CaSH II is active towards ketone substrates in asymmetric Diels,Alder reactions. The iminium intermediate of the catalytic cycle was isolated. When it was put back into the solution reaction system, the same level of yield and stereoselectivity was observed. Based on these observations, we argue that organocatlyst is actually an in situ chiral auxiliary. [source] Action-oriented representation of peripersonal and extrapersonal space: Insights from manual and locomotor actions1JAPANESE PSYCHOLOGICAL RESEARCH, Issue 3 2006TAKAHIRO HIGUCHI Abstract:, This paper reviews behavioral evidence demonstrating that space is accurately represented in the brain in relation to action capabilities. We initially review intriguing neuropsychological findings that show that space is differentially represented depending on whether the area is in reach of the hand (peripersonal space) or out of reach of the hand (extrapersonal space). We then review the literature on the characteristics of locomotor actions for avoiding obstacles to show that the relative dimensions of obstacles to relevant body parts are accurately represented at least one step before the obstacles are reached, i.e., while the obstacles are present in the extrapersonal space. The findings obtained from a number of studies on manual and locomotor actions will yield tentative conclusions: (a) the representation of one's body (body schema) is deeply involved in one's representation of space; (b) the representation of space is modified in response to alteration of action capabilities, although this is likely to occur only for well-learned actions, irrespective of the type; and (c) representation of space centered on the hand somewhat differs from that centered on the whole body. [source] Novel [Ruthenium(substituted-tetramethylcyclopentadiene) (2-quinolinecarboxylato)(allyl)] Hexafluorophosphate Complexes as Efficient Catalysts for Highly Regioselective Nucleophilic Substitution of Aliphatic Allylic SubstratesADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 10 2008Hui-Jun Zhang Abstract Stable [ruthenium(R-substituted-tetramethylcyclopentadiene)(2-quinolinecarboxylato)(1-R,-substituted-allyl) hexafluorophosphate (R=Me, R,=H, Me, n- Pr, Ph; R=t- Bu, R,=Me) and [ruthenium(pentamethylcyclopentadiene)(2-quinolinecarboxylato)(1- n -propylallyl)] tetrafluoroborate (4,a), as allylruthenium(IV) complexes, have been synthesized in one step, starting from [ruthenium(R-substituted-tetramethylcyclopentadiene)tris(acetonitrile) hexafluorophosphate or tetrafluoroborate complexes, quinaldic acid, and allylic alcohols. Single stereoisomers are obtained and the X-ray single crystal structure determinations of 3b (R=t- Bu, R,=Me) and 4,a allow one to specify the preferred arrangement. Complexes 3a (R=R,=Me) and 3b are involved as precatalysts favoring the formation of branched products in regioselective nucleophilic allylic substitution reactions, starting from ethyl 2- (E) -hexen-1-yl carbonate and chlorohexene as unsymmetrical aliphatic allylic substrates. Phenols, dimethyl malonate, and primary (aniline) and secondary (pyrrolidine, piperidine) amines have been used as nucleophiles under mild basic conditions. For the first time, the regioselectivity in favor of the branched product obtained from purely aliphatic allylic substrates is close to the high regioselectivity previously reached starting from cinnamyl-type substrates in the presence of ruthenium catalysts. [source] Stabilization of penicillin V acylase from Streptomyces lavendulae by covalent immobilizationJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 5 2001Jesús Torres-Bacete Abstract Penicillin,V acylase from the actinomycete Streptomyces lavendulae ATCC 13664 has been immobilized to epoxy-activated acrylic beads (Eupergit C®) by covalent binding. Further linkage of bovine serum albumin after enzyme immobilization was carried out in order to remove the remaining oxirane groups of the support. The obtained immobilized biocatalyst displayed double exponential deactivation kinetics at temperatures below 55,°C, while the native enzyme followed single exponential decay at the same temperatures. We concluded that soluble penicillin acylase was deactivated in one step, whereas the immobilized enzyme showed an enzymatic intermediate state which is highly thermostable. As a consequence of the immobilization process, the enzyme displayed a 10-fold increase in its half-life at 40,°C. At this temperature, the enzymatic intermediate state was progressively destabilized as the pH of the medium was increased. Thus, the optimum pH range for the immobilized enzyme preparation was established as being from 7.0 to 8.0. Higher pH values led to quicker enzyme deactivation. © 2001 Society of Chemical Industry [source] A convenient route to synthesize 1,2,4-triazolo[1,5- a]pyrimidine derivatives and their one and two-photon absorption spectral propertiesJOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 5 2007Hongli Wang A convenient method for synthesizing ,-(1,2,4-triazolo[1,5- a]pyrimidine-2-sulfonyl)methane derivatives, 3 and 4, by the well known Knoevenagel reaction, in one step, is described. The two chromophores are stilbene-type chromophores containing the same D-,-A structures and end-capped with aromatic group as their donors. Measured with femtosecond multipass Ti:sapphire amplifier as irradiation source (pumped by the laser at 800 nm), the two chromophores show efficient two-photon induced orange red fluorescence emission. The experimental results indicate that the numbers of branches of the two chromophores affect their one-photon properties and two-photon up-conversion emission behaviors, and with the increasing numbers of branches, their wavelengths of ,absmax, ,spfmax and ,tpfmax exhibit bathochromic shifts. [source] Synthesis of models of metabolites: Oxidation of variously substituted chromenes including acronycine, by a porphyrin catalytic systemJOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 7 2005Bernardin Akagah The influence of chemical neighbouring on oxidation of substituted 2,2-dimethylchromenes derivatives 5-8 by a biomimetic catalytic system was first studied. It was then applied to acronycine an anti-cancer drug in order to obtain in one single step oxidized products resulting from the reactivity of the 1,2-double bond in the pyranic D-ring. These 2,2-dimethylchromenes constitute the structural moiety responsible for the activity of acronycine. This oxidation showed the sensitivity of the ethylenic bond, leading to the formation of the corresponding epoxides, diols and/or ketoalcohol. In the case of 5-dimethylamino-2,2-dimethylchromene 8, the double bond was not sensitive to oxidation, but the N -methyl groups reacted to lead to the formamide derivative 16 and an imino-alcohol 17. This methodology applied to acronycine molecule 1, allowed to obtain in one step, two oxidized compounds, a trans -diol 3 and a ketoalcohol 4 under preparative conditions. [source] Syntheses of [14C]BAY 59-7939 and its radiolabeled metabolite M-4JOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 11 2006U. Pleiss Abstract BAY 59-7939 is a novel, oral, direct Factor Xa inhibitor in clinical development for the prevention and treatment of thromboembolic diseases. Radiolabeled BAY 59-7939 was required for drug absorption, distribution, metabolism and excretion (ADME studies). The BAY 59-7939 was labeled with carbon-14 in the carboxamide group in one step in an overall radiochemical yield of 85% starting from 4-{4-[(5S)-5-(aminomethyl)-2-oxo-1,3-oxazolidin-3-yl]phenyl}mor-pholin-3-one and 5-chlorothiophene-2-[14C]carboxylic acid. The radiolabeled metabolite M-4 was prepared in 77% yield starting from [1- 14C]glycine and 5-chlorothiophene-5-carboxylic acid. Copyright © 2006 John Wiley & Sons, Ltd. [source] Syntheses of [2H3, 15N], [14C]NexavarÔ and its labeled metabolitesJOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 7 2006U. Pleiss Abstract NexavarÔ, Sorafenib tosylate (BAY 43-9006 tosylate) is a potent small molecule Raf kinase inhibitor for the treatment of hyperproliferative disorders such as cancer. Both radiolabeled and stable isotope labeled compounds were required for drug absorption, distribution, metabolism and excretion (ADME) and quantitative mass spectrometry bio-analytical studies. NexavarÔ labeled with carbon-14 in the carboxamide group was prepared in two steps in an overall radiochemical yield of 42% starting from 4-chloro- N -methyl-2-pyridine-[14C]carboxamide. The [2H3,15N] version of NexavarÔ was prepared in 75% yield based on 4-chloro- N -[2H3]methyl-2-pyridine-[15N]carboxamide. The pyridine N -oxide metabolite labeled with carbon-14 as well as with deuterium and nitrogen-15 and was synthesized by oxidation in yields of 59% and 87%, respectively. Starting from [2H2, 13C]formaldehyde the N -hydroxymethyl metabolite was labeled with carbon-13 and deuterium in one step in a 45% overall yield. Copyright © 2006 John Wiley & Sons, Ltd. [source] Synthesis of 13C-labelled cinnamonitrileJOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 2 2002Elizabeth M. Zippi Abstract 13C-labelled cinnamonitrile, a compound that possesses both the aromatic functionality of styrene and the nitrile functionality of acrylonitrile has been synthesized in one step using , -bromostyrene and potassium [13C]cyanide. The preparation of a target material using 13C -labelled cinnamonitrile may provide a cost-effective method for producing nitrogen-13 via proton irradiation for Positron Emission Tomography. Copyright © 2002 John Wiley & Sons, Ltd. [source] Ultrathin polymeric interpenetration network with separation performance approaching ceramic membranes for biofuelAICHE JOURNAL, Issue 1 2009Lan Ying Jiang Abstract Biofuel has emerged as one of the most strategically important sustainable fuel sources. The success of biofuel development is not only dependent on the advances in genetic transformation of biomass into biofuel, but also on the breakthroughs in separation of biofuel from biomass. The "separation" alone currently accounts for 60,80% of the biofuel production cost. Ceramic membranes made of sophisticated processes have shown separation performance far superior to polymeric membranes, but suffers fragility and high fabrication cost. We report the discovery of novel molecular engineering and membrane fabrication that can synergistically produce polymeric membranes exhibiting separation performance approaching ceramic membranes. The newly discovered Polysulfone/Matrimid composite membranes are fabricated by dual-layer coextrusion technology in just one step through phase inversion. An ultrathin dense-selective layer made of an interpenetration network of the two materials with a targeted and stable interstitial space is formed at the interface of two layers for biofuel separation. The combined molecular engineering and membrane fabrication approach may revolutionize future membrane research and development for purification and separation in energy, environment, and pharmaceuticals. © 2008 American Institute of Chemical Engineers AIChE J, 2009 [source] Room-temperature RAFT copolymerization of 2-chloroallyl azide with methyl acrylate and versatile applications of the azide copolymersJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 6 2010Guang Li Abstract A new vinyl azide monomer, 2-chlorallyl azide (CAA), has been synthesized from commercially available reagent in one step. The reversible addition fragmentation chain transfer (RAFT) copolymerization of CAA with methyl acrylate (MA) was carried out at room temperature using a redox initiator, benzoyl peroxide (BPO)/N,N -dimethylaniline (DMA), in the presence of benzyl 1H -imidazole-1-carbodithioate (BICDT). The polymerization results showed that the process bears the characteristics of controlled/living radical polymerizations, such as the molecular weight increasing linearly with the monomer conversion, the molecular weight distribution being narrow, and a linear relationship existing between ln([M]0/[M]) and the polymerization time. Chain extension polymerization was performed successfully to prepare block copolymer. Furthermore, the azide copolymers were functionalized by CuI -catalyzed "click" reaction with alkyne-containing poly(ethylene glycol) (PEG) to yield graft copolymers with hydrophilic PEG side chains. Surface modification of the glass sheet was successfully achieved via the crosslinking reaction of the azide copolymer under UV irradiation at ambient temperature. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1348,1356, 2010 [source] Emulsion synthesis of nanoparticles containing PEDOT using conducting polymeric surfactant: Synergy for colloid stability and intercalation dopingJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 7 2008Chi-an Dai Abstract Poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS) is a widely used conductive aqueous dispersion synthesized by using emulsion polymerization method. To further enhance its solution processability and conductivity of PEDOT derivatives, we proposed to replace the nonconductive PSS with conductive poly[2-(3thienyl)-ethoxy-4-butylsulfonate] (PTEB) as surfactant for the emulsion polymerization of PEDOT. The reaction involved colloid stabilization and doping in one step, and yielded PEDOT:PTEB composite nanoparticles with high electrical conductivity. Contrary to its counterpart containing nonconductive surfactant, PEDOT: PTEB showed increasing film conductivity with increasing PTEB concentration. The result demonstrates the formation of efficient electrical conduction network formed by the fully conductive latex nanoparticles. The addition of PTEB for EDOT polymerization significantly reduced the size of composite particles, formed stable spherical particles, enhanced thermal stability, crystallinity, and conductivity of PEDOT:PTEB composite. Evidence from UV,VIS and FTIR measurement showed that strong molecular interaction between PTEB and PEDOT resulted in the doping of PEDOT chains. X-ray analysis further demonstrated that PTEB chains were intercalated in the layered crystal structure of PEDOT. The emulsion polymerization of EDOT using conducting surfactant, PTEB demonstrated the synergistic effect of PTEB on colloid stability and intercalation doping of PEDOT during polymerization resulting in significant conductivity improvement of PEDOT composite nanoparticles. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 2536,2548, 2008 [source] Liquid-crystalline thermosets by the curing of dimeric liquid-crystalline epoxyimine monomers with 2,4-toluene diisocyanateJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 16 2003David Ribera Abstract We studied the curing processes of several series of dimeric liquid-crystalline epoxyimine monomers with 2,4-toluene diisocyanate (TDI) alone or with added catalytic proportions of 4-(N,N -dimethylamino)pyridine. We obtained isotropic materials or liquid-crystalline thermosets with different degrees of order, which depended on the structures of the monomers. To fix ordered networks, we had to do the curing in two steps when TDI was used alone as the curing agent. However, when a tertiary amine was added in catalytic proportions, the ordered networks were fixed in just one step. In this way, we were able to fix both nematic and smectic mesophases. The significance of the polarization of the mesogen for obtaining liquid-crystalline thermosets was demonstrated. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 2521,2530, 2003 [source] | |||||||||||||||||||||||||||||||||||||||||||