WorldWideScience

Sample records for monomers eligible candidates

  1. 28 CFR 105.12 - Notification for candidates eligible for expedited processing.

    Science.gov (United States)

    2010-07-01

    ... Department: (1) The full name of the candidate; (2) A unique student identification number created by the... electronic mail. Only notifications sent from an electronic mail address registered as a Provider will be... passport number. The Provider must be able to reference these records by the unique student...

  2. Recovery of olefin monomers

    Science.gov (United States)

    Golden, Timothy Christoph; Weist, Jr., Edward Landis; Johnson, Charles Henry

    2004-03-16

    In a process for the production of a polyolefin, an olefin monomer is polymerised said polyolefin and residual monomer is recovered. A gas stream comprising the monomer and nitrogen is subjected to a PSA process in which said monomer is adsorbed on a periodically regenerated silica gel or alumina adsorbent to recover a purified gas stream containing said olefin and a nitrogen rich stream containing no less than 99% nitrogen and containing no less than 50% of the nitrogen content of the gas feed to the PSA process.

  3. Ionic Liquid Epoxy Resin Monomers

    Science.gov (United States)

    Paley, Mark S. (Inventor)

    2013-01-01

    Ionic liquid epoxide monomers capable of reacting with cross-linking agents to form polymers with high tensile and adhesive strengths. Ionic liquid epoxide monomers comprising at least one bis(glycidyl) N-substituted nitrogen heterocyclic cation are made from nitrogen heterocycles corresponding to the bis(glycidyl) N-substituted nitrogen heterocyclic cations by a method involving a non-nucleophilic anion, an alkali metal cation, epichlorohydrin, and a strong base.

  4. Monomer Migration and Annihilation Processes

    Institute of Scientific and Technical Information of China (English)

    KE Jian-Hong; LIN Zhen-Quan; ZHUANG You-Yi

    2005-01-01

    We propose a two-species monomer migration-annihilation model, in which monomer migration reactions occur between any two aggregates of the same species and monomer annihilation reactions occur between two different species. Based on the mean-field rate equations, we investigate the evolution behaviors of the processes. For the case with an annihilation rate kernel proportional to the sizes of the reactants, the aggregation size distribution of either species approaches the modified scaling form in the symmetrical initial case, while for the asymmetrical initial case the heavy species with a large initial data scales according to the conventional form and the light one does not scale. Moreover,at most one species can survive finally. For the case with aconstant annihilation rate kernel, both species may scale according to the conventional scaling law in the symmetrical case and survive together at the end.

  5. Medicaid Eligibility

    Science.gov (United States)

    ... Limits HCV Communication Medicaid Drug Rebate Program Pharmacy Pricing Program Releases State Drug Utilization Data State Prescription ... to determine financial eligibility for Medicaid, CHIP, and premium tax credits and cost sharing reductions available through ...

  6. GENERAL: Cluster Growth Through Monomer Adsorption Processes

    Science.gov (United States)

    Ke, Jian-Hong; Lin, Zhen-Quan; Chen, Xiao-Shuang

    2010-02-01

    We propose a monomer adsorption model, in which only the monomers are allowed to diffuse and adsorb onto other clusters. By means of the generalized rate equation we investigate the kinetic behavior of the system with a special rate kernel. For the system without monomer input, the concentration aj(t) of the Aj clusters (j > 1) asymptotically retains a nonzero quantity, while for the system with monomer input, it decays with time and vanishes finally. We also investigate the kinetics of an interesting model with fixed-rate monomer adsorption. For the case without monomer source, the evolution of the system will halt at a finite time; while the system evolves infinitely in time in the case with monomer source. Finally, we also suggest a connection between the fixed-rate monomer adsorption systems and growing networks.

  7. 42 CFR 21.27 - Eligibility; senior assistant grade.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Eligibility; senior assistant grade. 21.27 Section... COMMISSIONED OFFICERS Appointment § 21.27 Eligibility; senior assistant grade. Every candidate for examination for appointment in the grade of senior assistant shall meet the requirements for eligibility for...

  8. 42 CFR 21.26 - Eligibility; assistant grade.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Eligibility; assistant grade. 21.26 Section 21.26... OFFICERS Appointment § 21.26 Eligibility; assistant grade. (a) Requirements; all candidates. Except as otherwise provided in this section every candidate for examination for appointment in the grade of assistant...

  9. Surface active monomers synthesis, properties, and application

    CERN Document Server

    Borzenkov, Mykola

    2014-01-01

    This brief includes information on the background?of and development of synthesis of various types of surface active monomers. The authors explain the importance of utilization of surface active monomers for creation of surface active polymers? and the various biomedical applications of such compounds . This brief introduces techniques for the synthesis of novel types of surface active monomers, their colloidal and polymerizable properties and application for needs of medicine and biology.

  10. Cutin and suberin monomers are membrane perturbants.

    Science.gov (United States)

    Douliez, Jean-Paul

    2004-03-15

    The interaction between cutin and suberin monomers, i.e., omega -hydroxylpalmitic acid, alpha, omega -hexadecanedioic acid, alpha, omega --hexadecanediol, 12-hydroxylstearic acid, and phospholipid vesicles biomimicking the lipid structure of plant cell membranes has been studied by optical and transmission electron microscopy, quasielastic light scattering, differential scanning calorimetry, and (31)P solid-state NMR. Monomers were shown to penetrate model membranes until a molar ratio of 30%, modulating their gel to fluid-phase transition, after which monomer crystals also formed in solution. These monomers induced a decrease of the phospholipid vesicle size from several micrometers to about 300 nm. The biological implications of these findings are discussed.

  11. Polyelectrolyte properties of proteoglycan monomers

    Science.gov (United States)

    Li, Xiao; Reed, Wayne F.

    1991-03-01

    Light scattering measurements were made on proteoglycan monomers (PGM) over a wide range of ionic strengths Cs, and proteoglycan concentrations [PG]. At low Cs there were clear peaks in the angular scattering intensity curve I(q), which moved towards higher scattering wave numbers q, as [PG]1/3. This differs from the square root dependence of scattering peaks found by neutron scattering from more concentrated polyelectrolyte solutions. The peaks remained roughly fixed as Cs increased, but diminished in height, and superposed I(q) curves yielded a sort of isosbestic point. Under certain assumptions the static structure factor S(q) could be extracted from the measured I(q), and was found to retain a peak. A simple hypothesis concerning coexisting disordered and liquidlike correlated states is presented, which qualitatively accounts for the most salient features of the peaks. There was evidence of a double component scattering autocorrelation decay at low Cs, which, when resolved into two apparent diffusion coefficients, gave the appearance of simultaneous ``ordinary'' and ``extraordinary'' phases. The extraordinary phase was ``removable,'' however, by filtering. At higher Cs the proteoglycans appear to behave as random nonfree draining polyelectrolyte coils, with a near constant ratio of 0.67 between hydrodynamic radius and radius of gyration. The apparent persistence length varied as roughly the -0.50 power of ionic strength, similar to various linear synthetic and biological polyelectrolytes. Electrostatic excluded volume theory accounted well for the dependence of A2 on Cs.

  12. Controlling monomer-sequence using supramolecular templates

    OpenAIRE

    ten Brummelhuis, Niels

    2014-01-01

    The transcription and translation of information contained in nucleic acids that has been perfected by nature serves as inspiration for chemists to devise strategies for the creation of polymers with welldefined monomer sequences. In this review the various approaches in which templates (either biopolymers or synthetic ones) are used to influence the monomer-sequence are discussed.

  13. Novel fluoro-carbon functional monomer for dental bonding.

    Science.gov (United States)

    Yoshihara, K; Yoshida, Y; Hayakawa, S; Nagaoka, N; Kamenoue, S; Okihara, T; Ogawa, T; Nakamura, M; Osaka, A; Van Meerbeek, B

    2014-02-01

    Among several functional monomers, 10-methacryloxydecyl dihydrogen phosphate (10-MDP) bonded most effectively to hydroxyapatite (HAp). However, more hydrolysis-resistant functional monomers are needed to improve bond durability. Here, we investigated the adhesive potential of the novel fluoro-carbon functional monomer 6-methacryloxy-2,2,3,3,4,4,5,5-octafluorohexyl dihydrogen phosphate (MF8P; Kuraray Noritake Dental Inc., Tokyo, Japan) by studying its molecular interaction with powder HAp using solid-state nuclear magnetic resonance ((1)H MAS NMR) and with dentin using x-ray diffraction (XRD) and by characterizing its interface ultrastructure at dentin using transmission electron microscopy (TEM). We further determined the dissolution rate of the MF8P_Ca salt, the hydrophobicity of MF8P, and the bond strength of an experimental MF8P-based adhesive to dentin. NMR confirmed chemical adsorption of MF8P onto HAp. XRD and TEM revealed MF8P_Ca salt formation and nano-layering at dentin. The MF8P_Ca salt was as stable as that of 10-MDP; MF8P was as hydrophobic as 10-MDP; a significantly higher bond strength was recorded for MF8P than for 10-MDP. In conclusion, MF8P chemically bonded to HAp. Despite its shorter size, MF8P possesses characteristics similar to those of 10-MDP, most likely to be associated with the strong chemical bond between fluorine and carbon. Since favorable bond strength to dentin was recorded, MF8P can be considered a good candidate functional monomer for bonding.

  14. Cyclic Polymer with Alternating Monomer Sequence.

    Science.gov (United States)

    Zhu, Wen; Li, Zi; Zhao, Youliang; Zhang, Ke

    2015-11-01

    Cyclic polymers with alternating monomer sequence are synthesized for the first time based on the ring-closure strategy. Well-defined telechelic alternating polymers are synthesized by reversible addition-fragmentation chain transfer polymerization by copolymerizing the electron acceptor monomer of N-benzylmaleimide and donor monomer of styrene with a feed ratio of 1 between them. The corresponding cyclic alternating polymers are then produced by the UV-induced Diels-Alder click reaction to ring-close the linear alternating polymer precursors under highly diluted reaction solution.

  15. Local and systemic effects of unpolymerised monomers

    Directory of Open Access Journals (Sweden)

    Sulekha Siddharth Gosavi

    2010-01-01

    Full Text Available Methyl methacrylate (MMA, a widely used monomer in dentistry and medicine has been reported to cause abnormalities or lesions in several organs. Experimental and clinical studies have documented that monomers may cause a wide range of adverse health effects such as irritation to skin, eyes, and mucous membranes, allergic dermatitis, stomatitis, asthma, neuropathy, disturbances of the central nervous system, liver toxicity, and fertility disturbances.

  16. Synthesis of the diazonium (perfluoroalkyl) benzenesulfonimide monomer from Nafion monomer for proton exchange membrane fuel cells

    Science.gov (United States)

    Mei, Hua; D'Andrea, Dan; Nguyen, Tuyet-Trinh; Nworie, Chima

    2014-02-01

    One diazonium (perfluoroalkyl) benzenesulfonimide monomer, perfluoro-3, 6-dioxa-4-methyl-7-octene benzenesulfonyl imide, has been synthesized from Nafion monomer for the first time. With trifluorovinyl ether and diazonium precursors, the partially-fluorinated diazonium PFSI monomer can be polymerized and will provide chemically bonding with carbon electrode in proton exchange membrane fuel cells. A systematic study of the synthesis and characterization of this diazonium PFSI monomer has been conducted by varying reaction conditions. The optimized synthesis method has been established in the lab.

  17. 42 CFR 21.25 - Eligibility; junior assistant grade.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Eligibility; junior assistant grade. 21.25 Section... COMMISSIONED OFFICERS Appointment § 21.25 Eligibility; junior assistant grade. (a) Requirements; all candidates... for appointment in the grade of junior assistant: (1) Shall be a citizen of the United States; (2...

  18. Cationically polymerizable monomers derived from renewable sources

    Energy Technology Data Exchange (ETDEWEB)

    Crivello, J.V.

    1992-10-01

    The objectives of this project are to design and synthesize novel monomers which orginate from renewable biological sources and to carry out their rapid, efficient, pollution-free and energy efficient cationic polymerization to useful products under the influence of ultraviolet light or heat. A summary of the results of the past year's research on cationically polymerizable monomers derived from renewable sources is presented. Three major areas of investigation corresponding to the different classes of naturally occurring starting materials were investigated; epoxidized terpenes and natural rubber and vinyl ethers from alcohols and carbohydrates.

  19. Cationically polymerizable monomers derived from renewable sources

    Energy Technology Data Exchange (ETDEWEB)

    Crivello, J.V.

    1992-10-01

    The objectives of this project are to design and synthesize novel monomers which orginate from renewable biological sources and to carry out their rapid, efficient, pollution-free and energy efficient cationic polymerization to useful products under the influence of ultraviolet light or heat. A summary of the results of the past year's research on cationically polymerizable monomers derived from renewable sources is presented. Three major areas of investigation corresponding to the different classes of naturally occurring starting materials were investigated; epoxidized terpenes and natural rubber and vinyl ethers from alcohols and carbohydrates.

  20. Softening and elution of monomers in ethanol

    DEFF Research Database (Denmark)

    Benetti, Ana Raquel; Asmussen, Erik; Munksgaard, E Christian;

    2009-01-01

    The purpose of this study was to investigate the effect of light-curing protocol on softening and elution of monomers in ethanol as measured on a model polymer. It was a further aim to correlate the measured values with previously reported data on degree of conversion and glass transition tempera...

  1. Producing monomers and polymers from plant oils

    Science.gov (United States)

    The integration of biobased industrial products into existing markets, where petrochemically-derived materials currently dominate, is a worthy objective. This chapter reviews some technologies that have been developed including olefins of various chain lengths, photo-curable polymers, vinyl monomers...

  2. Release of monomers from composite dust.

    Science.gov (United States)

    Cokic, S M; Duca, R C; Godderis, L; Hoet, P H; Seo, J W; Van Meerbeek, B; Van Landuyt, K L

    2017-05-01

    Dental personnel are more at risk to develop asthmatic disease, but the exact reason is so far unknown. During abrasive procedures, dental personnel are exposed to nano-sized dust particles released from dental composite. The aim of this study was to investigate whether respirable composite dust may also release monomers. Respirable (composite dust was collected and the release of methacrylate monomers and Bisphenol A (BPA) in water and ethanol was evaluated by liquid chromatography/mass spectroscopy (LC-MS/MS). The dust was ultra-morphologically and chemically analyzed by transmission electron microscopy and energy-dispersive X-ray spectroscopy (TEM-EDS). LC-MS/MS analysis revealed that, irrespective of the type of composite, the respirable fraction of composite dust may release relatively high concentrations of unpolymerized methacrylate monomers, both in water and ethanol. Higher release was observed in ethanol. The endocrine disruptor BPA also emanated from the composite dust particles. TEM showed that most particles were nano-sized, although particle size ranged between 6nm and 5μm with a mode value between 12 and 39nm. Most particles consisted of several filler particles in resin matrix, although single nano-filler particles could also be observed. Elemental analysis by TEM-EDS proved that the particles collected on the filters originated from the dental composites. Theoretically, composite dust may function as a vehicle to transport monomers deeply into the respiratory system. The results of this study may shed another light on the increasing incidence of respiratory disease among dental personnel, and more care should be taken to prevent inhalation of composite dust. Special care should be taken to prevent inhalation of composite dust, as the dust particles may release methacrylate monomers. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Photokopolimerisasi monomer akrilat degan kulit kras sapi

    Directory of Open Access Journals (Sweden)

    Dwi Wahini Nurhajati

    1997-06-01

    Full Text Available The research on photocopolymerization of acrylate monomer with cow crust hide had object to observe the resulted copolymer onto cow crust hide. Crust hides, saturated with aqueous emulsions containing 25 wt % of n-butyl acrylate (n-BA or tripropylene glycol diacrylate (TPGDA were irradiated by cobalt – 60 gamma rays with doses ranges from 5 to 25 kGy. The irradiated hides were washed with water, dried in air and extracted in soxhlet apparatus for 48 hours to remove homopolymer. The highest yield of photocopolymerization of n – butyl acrylate monomer with crust hides was found 17,7878% at dose 25 kGy, and for photocopolymerization of tripropylene glycol diacrylate with crust hides was found 39,4245% at dose 20 kGy.

  4. Functionalization of nanodiamond with epoxy monomer

    Institute of Scientific and Technical Information of China (English)

    Huan Huan Zhang; Ya Ting Liu; Rong Wang; Xiao Yan Yu; Xiong Wei Qu; Qing Xin Zhang

    2011-01-01

    A novel nanodiamond-epoxy derivative (ND-EP) was synthesized by grafting epoxy monomers onto the surface of nanodiamond (ND), and characterized by FTIR and TGA. The ratio of grafted epoxy groups was determined to be 32.5 wt% by TGA. The developed methodology provides an efficient method for the functionalization of nanodiamond material, which enables a variety of advanced engineering and biomedical applications of ND.

  5. 21 CFR 888.4220 - Cement monomer vapor evacuator.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cement monomer vapor evacuator. 888.4220 Section... (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Surgical Devices § 888.4220 Cement monomer vapor evacuator. (a) Identification. A cement monomer vapor evacuator is a device intended for use during surgery to contain or...

  6. Kinetics of monomer biodegradation in soil.

    Science.gov (United States)

    Siotto, Michela; Sezenna, Elena; Saponaro, Sabrina; Innocenti, Francesco Degli; Tosin, Maurizio; Bonomo, Luca; Mezzanotte, Valeria

    2012-01-01

    In modern intensive agriculture, plastics are used in several applications (i.e. mulch films, drip irrigation tubes, string, clips, pots, etc.). Interest towards applying biodegradable plastics to replace the conventional plastics is promising. Ten monomers, which can be applied in the synthesis of potentially biodegradable polyesters, were tested according to ASTM 5988-96 (standard respirometric test to evaluate aerobic biodegradation in soil by measuring the carbon dioxide evolution): adipic acid, azelaic acid, 1,4-butanediol, 1,2-ethanediol, 1,6-hexanediol, lactic acid, glucose, sebacic acid, succinic acid and terephthalic acid. Eight replicates were carried out for each monomer for 27-45 days. The numerical code AQUASIM was applied to process the CO₂ experimental data in order to estimate values for the parameters describing the different mechanisms occurring to the monomers in soil: i) the first order solubilization kinetic constant, K(sol) (d⁻¹); ii) the first order biodegradation kinetic constant, K(b) (d⁻¹); iii) the lag time in biodegradation, t(lag) (d); and iv) the carbon fraction biodegraded but not transformed into CO₂, Y (-). The following range of values were obtained: [0.006 d⁻¹, 6.9 d⁻¹] for K(sol), [0.1 d⁻¹, 1.2 d⁻¹] for K(b), and [0.32-0.58] for Y; t(lag) was observed for azelaic acid, 1,2-ethanediol, and terephthalic acid, with estimated values between 3.0 e 4.9 d. Copyright © 2011 Elsevier Ltd. All rights reserved.

  7. Static and dynamical critical behavior of the monomer-monomer reaction model with desorption

    Science.gov (United States)

    da Costa, E. C.; Rusch, Flávio Roberto

    2016-06-01

    We studied in this work the monomer-monomer reaction model on a linear chain. The model is described by the following reaction: A + B → AB, where A and B are two monomers that arrive at the surface with probabilities yA and yB, respectively, and we have considered desorption of the monomer B with probability α. The model is studied in the adsorption controlled limit where the reaction rate is infinitely larger than the adsorption rate. We employ site and pair mean-field approximations as well as static and dynamical Monte Carlo simulations. We show that the model exhibits a continuous phase transition between an active steady state and an A-absorbing state, when the parameter yA is varied through a critical value, which depends on the value of α. Monte Carlo simulations and finite-size scaling analysis near the critical point are used to determine the static critical exponents β and ν⊥ and the dynamical critical exponents ν∥ and z. The results found for the monomer-monomer reaction model with B desorption, in the linear chain, are different from those found by E. V. Albano (Albano, 1992) and are in accordance with the values obtained by Jun Zhuo and Sidney Redner (Zhuo and Redner, 1993), and endorse the conjecture of Grassberger, which states that any system undergoing a continuous phase transition from an active steady state to a single absorbing state, exhibits the same critical behavior of the directed percolation universality class.

  8. Copolymerization of Carbon–carbon Double-bond Monomer (Styrene with Cyclic Monomer (Tetrahydrofuran

    Directory of Open Access Journals (Sweden)

    Sari Fouad

    2012-12-01

    Full Text Available We reported in this work that the cationic copolymerization in one step takes place between carbon–carbon double-bond monomer styrene with cyclic monomer tetrahydrofuran. The comonomers studied belong to different families: vinylic and cyclic ether. The reaction is initiated with maghnite-H+ an acid exchanged montmorillonite as acid solid ecocatalyst. Maghnite-H+ is already used as catalyst for polymerization of many vinylic and heterocyclic monomers. The oxonium ion of tetrahydrofuran and carbonium ion of styrene propagated the reaction of copolymerization. The acetic anhydride is essential for the maintenance of the ring opening of tetrahydrofuran and the entry in copolymerization. The temperature was kept constant at 40°C in oil bath heating for 6 hours. A typical reaction product was analyzed by 1H-NMR, 13C-NMR and IR and the formation of the copolymer was confirmed. The reaction was proved by matched with analysis. The maghnite-H+ allowed us to obtain extremely pure copolymer in good yield by following a simples operational conditions. Copyright © 2012 by BCREC UNDIP. All rights reservedReceived: 29th October 2012; Revised: 29th November 2012; Accepted: 29th November 2012[How to Cite: S. Fouad, M.I. Ferrahi, M. Belbachir. (2012. Copolymerization of Carbon–carbon Double-bond Monomer (Styrene with Cyclic Monomer (Tetrahydrofuran. Bulletin of Chemical Reaction Engineering & Catalysis, 7(2: 165-171. (doi:10.9767/bcrec.7.2.4074.165-171][How to Link / DOI: http://dx.doi.org/10.9767/bcrec.7.2.4074.165-171 ] | View in 

  9. Computational screening of oxetane monomers for novel hydroxy terminated polyethers.

    Science.gov (United States)

    Sarangapani, Radhakrishnan; Ghule, Vikas D; Sikder, Arun K

    2014-06-01

    Energetic hydroxy terminated polyether prepolymers find paramount importance in search of energetic binders for propellant applications. In the present study, density functional theory (DFT) has been employed to screen the various novel energetic oxetane derivatives, which usually construct the backbone for these energetic polymers. Molecular structures were investigated at the B3LYP/6-31G* level, and isodesmic reactions were designed for calculating the gas phase heats of formation. The condensed phase heats of formation for designed compounds were calculated by the Politzer approach using heats of sublimation. Among the designed oxetane derivatives, T4 and T5 possess condensed phase heat of formation above 210 kJ mol(-1). The crystal packing density of the designed oxetane derivatives varied from 1.2 to 1.6 g/cm(3). The detonation velocities and pressures were evaluated using the Kamlet-Jacobs equations, utilizing the predicted densities and HOFCond. It was found that most of the designed oxetane derivatives have detonation performance comparable to the monomers of benchmark energetic polymers viz., NIMMO, AMMO, and BAMO. The strain energy (SE) for the oxetane derivatives were calculated using homodesmotic reactions, while intramolecular group interactions were predicted through the disproportionation energies. The concept of chemical hardness is used to analyze the susceptibility of designed compounds to reactivity and chemical transformations. The heats of formation, density, and predicted performance imply that the designed molecules are expected to be candidates for polymer synthesis and potential molecules for energetic binders.

  10. Synthesis and photoactivity of phenylazonaphthalene peptide nucleic acid monomers

    Institute of Scientific and Technical Information of China (English)

    Jin Du Li; Miao Chen; Sheng Liu; Hao Bo Zhang; Zhi Lu Liu

    2008-01-01

    Phenylazonaphthalene peptide nucleic acid (PNA) monomers were successfully synthesized,and their photoisomerization was examined.The new PNA monomers showed reversible trans-cis isomerization with UV and visible light irradiation,which might be the foundation of photo-regulating the hybridization between PNA containing phenylazonaphthalene unit and DNA.Simultaneously,the fluorescence of the new PNA monomers might make them especially useful as structural probes.

  11. The practice of using Phenol inhibitors in obtaining monomers

    Energy Technology Data Exchange (ETDEWEB)

    Kurbatov, V.A.; Kirpichnikov, P.A.; Likumovich, A.G.

    1983-01-01

    Phenol antioxidants are promising stabilizers for the industrial production of monomers. Their potential may be considerably improved by searching for optimum compositions and conditions of application.

  12. Can the hydrophilicity of functional monomers affect chemical interaction?

    Science.gov (United States)

    Feitosa, V P; Ogliari, F A; Van Meerbeek, B; Watson, T F; Yoshihara, K; Ogliari, A O; Sinhoreti, M A; Correr, A B; Cama, G; Sauro, S

    2014-02-01

    The number of carbon atoms and/or ester/polyether groups in spacer chains may influence the interaction of functional monomers with calcium and dentin. The present study assessed the chemical interaction and bond strength of 5 standard-synthesized phosphoric-acid ester functional monomers with different spacer chain characteristics, by atomic absorption spectroscopy (AAS), ATR-FTIR, thin-film x-ray diffraction (TF-XRD), scanning electron microscopy (SEM), and microtensile bond strength (μTBS). The tested functional monomers were 2-MEP (two-carbon spacer chain), 10-MDP (10-carbon), 12-MDDP (12-carbon), MTEP (more hydrophilic polyether spacer chain), and CAP-P (intermediate hydrophilicity ester spacer). The intensity of monomer-calcium salt formation measured by AAS differed in the order of 12-MDDP=10-MDP>CAP-P>MTEP>2-MEP. FTIR and SEM analyses of monomer-treated dentin surfaces showed resistance to rinsing for all monomer-dentin bonds, except with 2-MEP. TF-XRD confirmed the weaker interaction of 2-MEP. Highest µTBS was observed for 12-MDDP and 10-MDP. A shorter spacer chain (2-MEP) of phosphate functional monomers induced formation of unstable monomer-calcium salts, and lower chemical interaction and dentin bond strength. The presence of ester or ether groups within longer spacer carbon chains (CAP-P and MTEP) may affect the hydrophilicity, μTBS, and also the formation of monomer-calcium salts.

  13. Interference of functional monomers with polymerization efficiency of adhesives.

    Science.gov (United States)

    Hanabusa, Masao; Yoshihara, Kumiko; Yoshida, Yasuhiro; Okihara, Takumi; Yamamoto, Takatsugu; Momoi, Yasuko; Van Meerbeek, Bart

    2016-04-01

    The degree of conversion (DC) of camphorquinone/amine-based adhesives is affected by acidic functional monomers as a result of inactivation of the amine co-initiator through an acid-base reaction. During bonding, functional monomers of self-etch adhesives chemically interact with hydroxyapatite (HAp). Here, we tested in how far the latter interaction of functional monomers with HAp counteracts the expected reduction in DC of camphorquinone/amine-based adhesives. The DC of three experimental adhesive formulations, containing either of the two functional monomers [10-methacryloyloxydecyl dihydrogen phosphate (10-MDP) or 4-methacryloxyethyl trimellitic acid anhydride (4-META)] or no functional monomer (no-FM; control), was measured with and without HAp powder added to the adhesive formulations. Both the variables 'functional monomer' and 'HAp' were found to be significant, with the functional monomer reducing the DC and HAp counteracting this effect. It is concluded that the functional monomers 10-MDP and 4-META interfere with the polymerization efficiency of adhesives. This interference is less prominent in the presence of HAp, which would clinically correspond to when these two functional monomers of the adhesive simultaneously interact with HAp in tooth tissue.

  14. A review of the developments of multi-purpose primers and adhesives comprising novel dithiooctanoate monomers and phosphonic acid monomers.

    Science.gov (United States)

    Ikemura, Kunio; Endo, Takeshi; Kadoma, Yoshinori

    2012-02-03

    This paper reviews the developments of dithiooctanoate monomers and acidic adhesive monomers, and their roles in multi-purpose primers and adhesives in promoting adhesion to multiple substrate materials. Novel dithiooctanoate monomers exhibited excellent bonding to precious metals and alloys when compared against conventional sulfur-containing monomers. Newly developed phosphonic acid monomers, endowed with a water-soluble nature, enabled sufficient demineralization of dental hard tissues and thus improved bonding to both ground enamel and dentin. The optimal combination for bonding to dental hard tissues and precious and non-precious metals and alloys was 5.0 wt% 10-methacryloyloxydecyl 6,8-dithiooctanoate (10-MDDT) and 1.0 wt% 6-methacryloyloxyhexyl phosphonoacetate (6-MHPA). For bonding to dental porcelain, alumina, zirconia, and gold (Au) alloy, a ternary combination of silane coupling agent, acidic adhesive monomers, and dithiooctanoate monomers seemed promising. The latest development was a single-bottle, multi-purpose, self-etching adhesive which contained only acidic adhesive monomers and dithiooctanoate monomers but which produced strong adhesion to ground enamel and dentin, sandblasted zirconia, and Au alloy.

  15. DFT studies of all fluorothiophenes and their cations as candidate monomers for conductive polymers

    Energy Technology Data Exchange (ETDEWEB)

    Shirani, Hossein, E-mail: shiranihossein@gmail.com [Young Researchers Club, Islamic Azad University, Toyserkan Branch, Toyserkan (Iran, Islamic Republic of); Jameh-Bozorghi, Saeed [Department of Chemistry, Islamic Azad University, Arak Branch, Arak (Iran, Islamic Republic of); Yousefi, Ali [Department of Computer Engineering, Islamic Azad University, Hamedan Branch, Hamedan (Iran, Islamic Republic of)

    2015-01-22

    In this paper, electronic, structural, and properties of mono-, di-, tri-, and tetrafluorothiophenes and their radical cations are studied using the density functional theory and B3LYP method with 6-311++G** basis set. Also, the effects of the number and position of the substituent of fluorine atoms on the properties of the thiophene ring have been studied using optimized structures obtained for these molecules and their radical cations; vibrational frequencies, spin-density distribution, size and direction of the dipole moment vector, ionization potential, electric Polarizabilities, HOMO–LUMO gaps and NICS values of these compounds have been calculated and analyzed.

  16. Plasma-Enhanced Copolymerization of Amino Acid and Synthetic Monomers

    Science.gov (United States)

    2011-12-16

    end cap containing a second inlet for the liquid monomer delivery (Scheme 1). The solid L-tyrosine monomer was placed in a resistively heated tantalum ...microroughness, which is indicative of uniform cross-linking and wetting of the deposits of all components. These films are free of pinhole defects as well

  17. Oligonucleotides with 1,4-dioxane-based nucleotide monomers

    DEFF Research Database (Denmark)

    Madsen, Andreas S; Wengel, Jesper

    2012-01-01

    An epimeric mixture of H-phosphonates 5R and 5S has been synthesized in three steps from known secouridine 1. Separation of the epimers has been accomplished by RP-HPLC, allowing full characterization and incorporation of monomers X and Y into 9-mer oligonucleotides using H-phosphonates building...... blocks 5R and 5S, respectively. A single incorporation of either monomer X or monomer Y in the central position of a DNA 9-mer results in decreased thermal affinity toward both DNA and RNA complements (ΔT(m) = -3.5 °C/-3.5 °C for monomer X and ΔT(m) = -11.0 °C/-6.5 °C for monomer Y). CD measurements do...

  18. Monomer-dimer tatami tilings of square regions

    CERN Document Server

    Erickson, Alejandro

    2011-01-01

    We prove that the number of monomer-dimer tilings of an $n\\times n$ square grid, with $mmonomers in which no four tiles meet at any point is $m2^m+(m+1)2^{m+1}$, when $m$ and $n$ have the same parity. In addition, we present a new proof of the result that there are $n2^{n-1}$ such tilings with $n$ monomers, which divides the tilings into $n$ classes of size $2^{n-1}$. The sum of these tilings over all monomer counts has the closed form $2^{n-1}(3n-4)+2$ and, curiously, this is equal to the sum of the squares of all parts in all compositions of $n$. We also describe two algorithms and a Gray code ordering for generating the $n2^{n-1}$ tilings with $n$ monomers, which are both based on our new proof.

  19. 42 CFR 21.29 - Eligibility; grades above senior assistant grade.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Eligibility; grades above senior assistant grade... PERSONNEL COMMISSIONED OFFICERS Appointment § 21.29 Eligibility; grades above senior assistant grade. Every candidate for examination for appointment in grades above that of senior assistant shall meet the...

  20. 76 FR 77831 - 2012 Presidential Candidate Matching Fund Submission Dates and Post Date of Ineligibility Dates...

    Science.gov (United States)

    2011-12-14

    ... 2012 Presidential Candidate Matching Fund Submission Dates and Post Date of Ineligibility Dates To...: Notice of matching fund submission dates and submission dates for statements of net outstanding campaign... fund submission dates for publicly funded 2012 presidential primary candidates. Eligible candidates...

  1. 7 CFR 1421.302 - Eligible producer and eligible land.

    Science.gov (United States)

    2010-01-01

    ... the 2008 Through 2012 Crop of Wheat, Barley, Oats, and Triticale § 1421.302 Eligible producer and... producer of wheat, barley, oats, or triticale in the 2008 through 2012 crop years. Also, to be an eligible... other eligible criteria for obtaining loan deficiency payments. (2) For producers of triticale...

  2. Study on the preirradiation polymerization of vinyl monomers

    Science.gov (United States)

    Yu-Ming, Liu; Yue-Qi, Yang; Zue-Teh, Ma

    This paper presents mainly the polymerization, copolymerization and crosslinking of monomers off-source induced by peroxides which are formed by high energy irradiation of vinyl monomers such as styrene (St), acrylonitrile (AN), methylmethacrylate (MMA), vinyl acetate (VAc) and 2-hydroxyethyl methacrylate (HEMA). The peroxides produced by irradiation of the above-mentioned monomers can not only induce the monomers themselves, but also another non-irradiated monomer to carry out copolymerization efficiently. The activation energy of peroxide formation, the apparent activation energy of polymerization and the activation energy of peroxide initiation by irradiation of vinyl monomers are: Ef(MMA) = 11, Ef(St) = 9.6, Ef(AN) = 8.5, EMMA = EVA = 11.4, Ei(MMA) = Ei(VA) = 13 kcal/mol. The rate of decomposition of monomer peroxides is smoother than that of BPO during the polymerization and so a smooth kinetic progress is obtained. The initiating ability of forming peroxides by irradiation of the vinyl monomers depends mainly on the chemical structure of the monomers. For instance, the main structure of peroxides formed during preirradiation MMA are: alternating peroxy-copolymer ? and random peroxy-copolymer ? Owing to the peroxy-bond which is unstable and in which homolytic breakage easily occurs to yield a pair of radicals, RO . is formed within the above-mentioned structural compounds, so that they possess stronger initiating reactivity. It is quite evident that the initiating reactivity of AN peroxide will be greatly reduced because of the conjugate double bond. In other words, the initiating ability of AN peroxide is lower than MMA peroxide and St peroxide.

  3. Highly Efficient Synthesis of Allopurinol Locked Nucleic Acid Monomer by C6 Deamination of 8-Aza-7-bromo-7-deazaadenine Locked Nucleic Acid Monomer

    DEFF Research Database (Denmark)

    Kosbar, Tamer Reda El-Saeed; Sofan, M.; Abou-Zeid, L.;

    2013-01-01

    An allopurinol locked nucleic acid (LNA) monomer was prepared by a novel strategy through C6 deamination of the corresponding 8-aza-7-bromo-7-deazaadenine LNA monomer with aqueous sodium hydroxide. An 8-aza-7-deazaadenine LNA monomer was also synthesized by a modification of the new synthetic pat...... the required LNA monomers. © Georg Thieme Verlag....

  4. Eligibility for renal denervation

    DEFF Research Database (Denmark)

    Persu, Alexandre; Jin, Yu; Baelen, Marie;

    2014-01-01

    -resistant hypertension (ENCOReD). The analysis included 731 patients. Age averaged 61.6 years, office blood pressure at screening was 177/96 mm Hg, and the number of blood pressure-lowering drugs taken was 4.1. Specialists referred 75.6% of patients. The proportion of patients eligible for renal denervation according......Based on the SYMPLICITY studies and CE (Conformité Européenne) certification, renal denervation is currently applied as a novel treatment of resistant hypertension in Europe. However, information on the proportion of patients with resistant hypertension qualifying for renal denervation after...... undetected secondary causes of hypertension (11.1%). In conclusion, after careful screening and treatment adjustment at hypertension expert centers, only ≈40% of patients referred for renal denervation, mostly by specialists, were eligible for the procedure. The most frequent cause of ineligibility...

  5. 21 CFR 864.7300 - Fibrin monomer paracoagulation test.

    Science.gov (United States)

    2010-04-01

    ... to detect fibrin monomer in the diagnosis of disseminated intravascular coagulation (nonlocalized clotting within a blood vessel) or in the differential diagnosis between disseminated intravascular coagulation and primary fibrinolysis (dissolution of the fibrin in a blood clot). (b) Classification. Class...

  6. PHOTOINDUCED GRAFTING OF ACRYLIC AND ALLYL MONOMERS ON POLYETHYLENE SURFACE

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhenfeng; HU Xingzhou; YAN Qing

    1995-01-01

    Photoinduced grafting of acrylic and allyl monomers on polyethylene surface was generally studied by using benzophenone (BP) as a photoinitiator. The grafting process was carried out either in vapor-phase or in solution of the monomers. In the vapor-phase reaction with a filter used to cut off the short wavelength UV light, allyl amine is the most reactive of the four monomers used and acrylic amide is comparatively more reactive than acrylic acid and allyl alcohol. Acetone, as a solvent and carrier for initiator and monomers, however, shows its reactivity to participate the reaction. The solution grafting with a filter is much faster than the corresponding vapor-phase reaction, and a fully covered surface by the grafted polymer can be achieved in this way.

  7. PREPARATION AND SURFACE PROPERTIES OF ACRYLIC COPOLYMERS CONTAINING FLUORINATED MONOMERS

    Institute of Scientific and Technical Information of China (English)

    Tai-jiang Gui; Hao Wei; Ying Zhao; Xiu-lin Wang; Du-jin Wang; Duan-fu Xu

    2006-01-01

    A series of copolymers comprising butylmethacrylate, styrene, butylacrylate, hydroxypropyl acrylate and perfluoroalkyl methacrylate were synthesized by the free radical polymerization using BPO as an initiator. The surface property of the copolymer films was subsequently characterized. The contact angle measurements and energy dispersive analysis of X-ray (EDAX) show that the length and content ofperfluoroalkyl side chains in the copolymers are crucial for the preparation of the film with low surface energy. At a given content of fluorinated monomers in the copolymers, the longer the perfluoroalkyl side chain, the larger the water contact angle of the copolymer films will be. On the other hand, the higher the content of fluorinated monomers, the lower the surface energy is. The water contact angle increases with the increase of the fluorinated monomer content and reaches a plateau at 3 wt% of fluorinated monomer content.

  8. Composition of amino acids, fatty acids and dietary fibre monomers ...

    African Journals Online (AJOL)

    Composition of amino acids, fatty acids and dietary fibre monomers in kernels of ... Nuts are rich in protein and essential amino acids, and have a high energy value ... of protein, especially when combined with foods with high lysine content.

  9. Synthesis of Functional Polyethylene Copolymers via Reactive Monomer

    Institute of Scientific and Technical Information of China (English)

    Hua-yi Li; Shu-qing Zhang; Ling-zhi Wang; You-liang Hu

    2005-01-01

    @@ 1Introduction Polyolefins are used widely due to their good performance and low price, but the poor compatibility and adhesion with other materials limits their applications in broader areas. Reactive monomer approach is effective to synthesize functional polyolefins[1]. In this case, olefin is copolymerized with a reactive comonomer to produce reactive intermediary which is then converted to functional group or initiator to initiate graft-from polymerization of polar monomer.

  10. Perturbation of the Monomer-Monomer Interfaces of the Benzoylformate Decarboxylase Tetramer

    Energy Technology Data Exchange (ETDEWEB)

    Andrews, Forest H.; Rogers, Megan P.; Paul, Lake N.; McLeish, Michael J. [IUPUI; (Purdue)

    2014-08-14

    The X-ray structure of benzoylformate decarboxylase (BFDC) from Pseudomonas putida ATCC 12633 shows it to be a tetramer. This was believed to be typical of all thiamin diphosphate-dependent decarboxylases until recently when the structure of KdcA, a branched-chain 2-keto acid decarboxylase from Lactococcus lactis, showed it to be a homodimer. This lent credence to earlier unfolding experiments on pyruvate decarboxylase from Saccharomyces cerevisiae that indicated that it might be active as a dimer. To investigate this possibility in BFDC, we sought to shift the equilibrium toward dimer formation. Point mutations were made in the noncatalytic monomer–monomer interfaces, but these had a minimal effect on both tetramer formation and catalytic activity. Subsequently, the R141E/Y288A/A306F variant was shown by analytical ultracentrifugation to be partially dimeric. It was also found to be catalytically inactive. Further experiments revealed that just two mutations, R141E and A306F, were sufficient to markedly alter the dimer–tetramer equilibrium and to provide an ~450-fold decrease in kcat. Equilibrium denaturation studies suggested that the residual activity was possibly due to the presence of residual tetramer. The structures of the R141E and A306F variants, determined to <1.5 Å resolution, hinted that disruption of the monomer interfaces will be accompanied by movement of a loop containing Leu109 and Leu110. As these residues contribute to the hydrophobicity of the active site and the correct positioning of the substrate, it seems that tetramer formation may well be critical to the catalytic activity of BFDC.

  11. 7 CFR 915.160 - Public member eligibility requirements and nomination procedures.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Public member eligibility requirements and nomination... requirements and nomination procedures. (a) Public member and alternate member candidates shall not represent... candidates should be able to devote sufficient time to attend committee activities regularly and...

  12. Monomers of cutin biopolymer: sorption and esterification on montmorillonite surfaces

    Science.gov (United States)

    Olshansky, Yaniv; Polubesova, Tamara; Chefetz, Benny

    2013-04-01

    One of the important precursors for soil organic matter is plant cuticle, a thin layer of predominantly lipids that cover all primary aerial surfaces of vascular plants. In most plant species cutin biopolymer is the major component of the cuticle (30-85% weight). Therefore cutin is the third most abundant plant biopolymer (after lignin and cellulose). Cutin is an insoluble, high molecular weight bio-polyester, which is constructed of inter-esterified cross linked hydroxy-fatty acids and hydroxyepoxy-fatty acids. The most common building blocks of the cutin are derivatives of palmitic acid, among them 9(10),16 dihydroxy palmitic acid (diHPA) is the main component. These fatty acids and their esters are commonly found in major organo-mineral soil fraction-humin. Hence, the complexes of cutin monomers with minerals may serve as model of humin. Both cutin and humin act as adsorption efficient domains for organic contaminants. However, only scarce information is available about the interactions of cutin with soil mineral surfaces, in particular with common soil mineral montmorillonite. The main hypothesize of the study is that adsorbed cutin monomers will be reconstituted on montmorillonite surface due to esterification and oligomerization, and that interactions of cutin monomers with montmorillonite will be affected by the type of exchangeable cation. Cutin monomers were obtained from the fruits of tomato (Lycopersicon esculentum). Adsorption of monomers was measured for crude Wyoming montmorillonites and montmorillonites saturated with Fe3+ and Ca2+. To understand the mechanism of monomer-clay interactions and to evaluate esterification on the clay surface, XRD and FTIR analyses of the montmorillonite-monomers complexes were performed. Our results demonstrated that the interactions of cutin monomers with montmorillonite are affected by the type of exchangeable cation. Isotherms of adsorption of cutin monomers on montmorillonites were fitted by a dual mode model of

  13. Comparative study on adhesive performance of functional monomers.

    Science.gov (United States)

    Yoshida, Y; Nagakane, K; Fukuda, R; Nakayama, Y; Okazaki, M; Shintani, H; Inoue, S; Tagawa, Y; Suzuki, K; De Munck, J; Van Meerbeek, B

    2004-06-01

    Mild self-etch adhesives demineralize dentin only partially, leaving hydroxyapatite around collagen within a submicron hybrid layer. We hypothesized that this residual hydroxyapatite may serve as a receptor for chemical interaction with the functional monomer and, subsequently, contribute to adhesive performance in addition to micro-mechanical hybridization. We therefore chemically characterized the adhesive interaction of 3 functional monomers with synthetic hydroxyapatite, using x-ray photoelectron spectroscopy and atomic absorption spectrophotometry. We further characterized their interaction with dentin ultra-morphologically, using transmission electron microscopy. The monomer 10-methacryloxydecyl dihydrogen phosphate (10-MDP) readily adhered to hydroxyapatite. This bond appeared very stable, as confirmed by the low dissolution rate of its calcium salt in water. The bonding potential of 4-methacryloxyethyl trimellitic acid (4-MET) was substantially lower. The monomer 2-methacryloxyethyl phenyl hydrogen phosphate (phenyl-P) and its bond to hydroxyapatite did not appear to be hydrolytically stable. Besides self-etching dentin, specific functional monomers have additional chemical bonding efficacy that is expected to contribute to their adhesive potential to tooth tissue.

  14. The limits of precision monomer placement in chain growth polymerization

    Science.gov (United States)

    Gody, Guillaume; Zetterlund, Per B.; Perrier, Sébastien; Harrisson, Simon

    2016-02-01

    Precise control over the location of monomers in a polymer chain has been described as the `Holy Grail' of polymer synthesis. Controlled chain growth polymerization techniques have brought this goal closer, allowing the preparation of multiblock copolymers with ordered sequences of functional monomers. Such structures have promising applications ranging from medicine to materials engineering. Here we show, however, that the statistical nature of chain growth polymerization places strong limits on the control that can be obtained. We demonstrate that monomer locations are distributed according to surprisingly simple laws related to the Poisson or beta distributions. The degree of control is quantified in terms of the yield of the desired structure and the standard deviation of the appropriate distribution, allowing comparison between different synthetic techniques. This analysis establishes experimental requirements for the design of polymeric chains with controlled sequence of functionalities, which balance precise control of structure with simplicity of synthesis.

  15. Biosynthesis of Polyhydroxyalkanoates Consisting of Short-chain-length Monomers and Medium-chain-length Monomers by Pseudomonas YS1

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    A strain capable of producing polyhydroxyalkanoates (PHAs) consisting of short- and medium-chain-length monomers was identified as Pseudomonas sp.coded as YS1.The strain synthesized PHAs containing monomers of hydroxybutyrate(HB or C4) and/or hydroxyoctanoate (HO or C8) and/or hydroxydecanoate (HD or C10) when grown in various substrates including glucose, raw sugar, molasses and various fatty acids.It was found that growth temperature affected the HB and HO monomer contents in the PHA.HB content in PHA increased from mole fraction 69% at 26℃ to mole fraction 85% at 37℃ while HO content decreased from mole fraction 29% at 26℃ to mole fraction 12% at 37℃.The temperature effect provides a simple and effective way to control the PHA composition and hence control the PHA mechanical and other physical properties.Also, the fermentor experiment indicated that PHB formation was growth associated and HO monomer production was in fact promoted by N-limitation.This conclusion was further supported by the fact that the formation of PHB only polyester was observed only when C/N molar ratio was smaller than 20.Higher C/N ratio led to the formation of HO monomers in the polyesters.

  16. Monomer release from nanofilled and microhybrid dental composites after bleaching.

    Directory of Open Access Journals (Sweden)

    Masumeh Hasani Tabatabaee

    2014-02-01

    Full Text Available The aim of this study was to assess the effect of bleaching on elution of monomers from nanofilled and microhybrid composites.80 samples (5mm diameter and 3mm thickness of each composite were prepared. After curing, half of them were randomly polished. Each group was divided into 8 subgroups and immersed in water or 10%, 20% and 30% H2O2 for 3 or 8 hours. Eluted Bis-GMA (Bis-phenol A Glycidyl Dimethacrylate, TEGDMA (Triethyleneglycol Dimethacrylate, UDMA (Urethane Dimethacrylate and BisEMA (Bis-phenol A ethoxylate Dimethacrylate were quantified by high performance liquid chromatography and the results were analyzed by univariate ANOVA and t-test (P<0.05.Bleach significantly increased the overall release of monomers (P<0.001; TEGDMA was released more than Bis-GMA (P<0.001. Supreme released more TEGDMA compared to Z250 (P<0.001. Bleaching increased the release of this monomer (P<0.001. Increasing both the concentration of H2O2, and the immersion time, increased the release of TEGDMA (P<0.001. Polishing had no effect on release of this monomer (P=0.952. Supreme released more Bis-GMA than Z250 (P=0.000. The more concentrated H2O2 caused more elution of Bis-GMA (P= 0.003; while the effect of immersion time was not significant (P=0.824. Polishing increased the release of Bis-GMA (P=0.001. Neither the type of composite nor Bleaching had any effect on release of UDMA (P=0.972 and (P=0.811 respectively. Immersion duration increased the release of UDMA (P=0.002, as well as polishing (P=0.024.Bleaching increased the release of monomers. Nanofilled composites released more monomer than the microfilled.

  17. The study on mechanism of holographic recording in photopolymer with dual monomer

    Science.gov (United States)

    Zhai, Qianli; Tao, Shiquan; Wang, Dayong

    2010-06-01

    In this paper we study the dynamics of refractive index modulation in a dual-monomer photopolymer through grating growth under different experiment stages. By using different sets of parameters for vinyl monomers (NVC) and acrylate monomers (POEA) respectively, a composite dual-monomer model, extended from the uniform post-exposure (UPE) model for single monomer photopolymer, is proposed and fitted with the experiment data very well. Further discussions indicate that the dominant contribution to the total index modulation is made by NVC monomers, and a brief explanation of the function of POEA monomers is given.

  18. PMR polyimide composites for aerospace applications. [Polymerization of Monomer Reactants

    Science.gov (United States)

    Serafini, T. T.

    1984-01-01

    A novel class of addition-type polyimides has been developed in response to the need for high temperature polymers with improved processability. The new plastic materials are known as PMR (for in situ polymerization of monomer reactants) polyimides. The highly processable PMR polyimides have made it possible to realize much of the potential of high temperature resistant polymers. Monomer reactant combinations for several PMR polyimides have been identified. The present investigation is concerned with a review of the current status of PMR polyimides. Attention is given to details of PMR polyimide chemistry, the processing of composites and their properties, and aerospace applications of PMR-15 polyimide composites.

  19. Cationically polymerizable monomers derived from renewable sources. Annual performance report

    Energy Technology Data Exchange (ETDEWEB)

    Crivello, J.V.

    1992-10-01

    The objectives of this project are to design and synthesize novel monomers which orginate from renewable biological sources and to carry out their rapid, efficient, pollution-free and energy efficient cationic polymerization to useful products under the influence of ultraviolet light or heat. A summary of the results of the past year`s research on cationically polymerizable monomers derived from renewable sources is presented. Three major areas of investigation corresponding to the different classes of naturally occurring starting materials were investigated; epoxidized terpenes and natural rubber and vinyl ethers from alcohols and carbohydrates.

  20. [Influence Factors on Monomer Conversion of Dental Composite Resin].

    Science.gov (United States)

    Wang, Shuang; Gao, Yan; Wang, Jing; Zhang, Yan; Zhang, Yuntao; Wang, Fanghui; Wang, Qingshan

    2015-04-01

    Dental composite resin is a kind of material which has been widely used in dental restoration. Research has found that the influence of residual monomer on the material mechanical, chemical and biological properties cannot be ignored. This paper elaborates these harms of residual monomers. The effects of resin matrix, inorganic filler and initiating system, illumination, secondarily treatment on the degree of conversion were also analyzed. The paper also discusses the effective measures to increase the conversion, and offers theoretical basis for the clinical application and development of composite resin.

  1. Breathing zone concentrations of methylmethacrylate monomer during joint replacement operations

    DEFF Research Database (Denmark)

    Darre, E; Jørgensen, L G; Vedel, P;

    1992-01-01

    By use of a methylmethacrylate (MMA) Dräger tube and bellow bump, the breathing zone concentrations of MMA monomer were measured for the operating surgeon during cementation of the components of hip and knee joint prostheses. The highest recordings (50-100 p.p.m.) were encountered during cementat......By use of a methylmethacrylate (MMA) Dräger tube and bellow bump, the breathing zone concentrations of MMA monomer were measured for the operating surgeon during cementation of the components of hip and knee joint prostheses. The highest recordings (50-100 p.p.m.) were encountered during...

  2. Independent candidates in Mexico

    OpenAIRE

    Campos, Gonzalo Santiago

    2014-01-01

    In this paper we discuss the issue of independent candidates in Mexico, because through the so-called political reform of 2012 was incorporated in the Political Constitution of the Mexican United States the right of citizens to be registered as independent candidates. Also, in September 2013 was carried out a reform of Article 116 of the Political Constitution of the Mexican United States in order to allow independent candidates in each state of the Republic. However, prior to the constitutio...

  3. WH2 domain: a small, versatile adapter for actin monomers.

    Science.gov (United States)

    Paunola, Eija; Mattila, Pieta K; Lappalainen, Pekka

    2002-02-20

    The actin cytoskeleton plays a central role in many cell biological processes. The structure and dynamics of the actin cytoskeleton are regulated by numerous actin-binding proteins that usually contain one of the few known actin-binding motifs. WH2 domain (WASP homology domain-2) is a approximately 35 residue actin monomer-binding motif, that is found in many different regulators of the actin cytoskeleton, including the beta-thymosins, ciboulot, WASP (Wiskott Aldrich syndrome protein), verprolin/WIP (WASP-interacting protein), Srv2/CAP (adenylyl cyclase-associated protein) and several uncharacterized proteins. The most highly conserved residues in the WH2 domain are important in beta-thymosin's interactions with actin monomers, suggesting that all WH2 domains may interact with actin monomers through similar interfaces. Our sequence database searches did not reveal any WH2 domain-containing proteins in plants. However, we found three classes of these proteins: WASP, Srv2/CAP and verprolin/WIP in yeast and animals. This suggests that the WH2 domain is an ancient actin monomer-binding motif that existed before the divergence of fungal and animal lineages.

  4. Microstructure Control in the emulsion polymerization of fluorinated monomers

    Energy Technology Data Exchange (ETDEWEB)

    Apostolo, Marco [Ausimont R and D, Bollate (Italy); Morbidelli, Massimo [ETH Zentrum, Zuerich (Switzerland)

    1997-03-01

    In this paper a mathematical model able to evaluate the microstructure of fluorinated polymers is presented. The model uses the pseudo-homo polymerization approach to describe the kinetic evolution of polymerization reactions involving any number of monomer species. The molecular weight distribution is evaluated combining the classical leading moments method with a recently proposed model based on the numerical fractionation technique.

  5. Synthesis of a benzoxazine monomer containing maleimide and allyloxy groups

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A novel benzoxazine monomer 3-(4-allyloxy)phenyl-3,4-dihydro-2H-6-(N-maleimido)-1,3-benzoxazine (AMB) was synthesized and structure was confirmed by FT-IR, 1H NMR. Thermal analysis (DSC) of AMB showed the introduction of allyloxy group decreased melting point and exhibited a narrow and symmetric curing exothermic window.

  6. Influence of the Diene Monomer on Devulcanization of EPDM Rubber

    NARCIS (Netherlands)

    Verbruggen, M.A.L.; van der Does, L.; Noordermeer, Jacobus W.M.; van Duin, M.

    2008-01-01

    Ethylene–propylene–diene rubbers (EPDM) with 2-ethylidene-5-norbornene (ENB), dicyclopentadiene (DCPD), and 1,4-hexadiene (HD) as third monomers have been vulcanized with peroxide and with a conventional sulfur vulcanization recipe, and their devulcanization was subsequently investigated for

  7. Epoxy resin monomers with reduced skin sensitizing potency.

    Science.gov (United States)

    O'Boyle, Niamh M; Niklasson, Ida B; Tehrani-Bagha, Ali R; Delaine, Tamara; Holmberg, Krister; Luthman, Kristina; Karlberg, Ann-Therese

    2014-06-16

    Epoxy resin monomers (ERMs), especially diglycidyl ethers of bisphenol A and F (DGEBA and DGEBF), are extensively used as building blocks for thermosetting polymers. However, they are known to commonly cause skin allergy. This research describes a number of alternative ERMs, designed with the aim of reducing the skin sensitizing potency while maintaining the ability to form thermosetting polymers. The compounds were designed, synthesized, and assessed for sensitizing potency using the in vivo murine local lymph node assay (LLNA). All six epoxy resin monomers had decreased sensitizing potencies compared to those of DGEBA and DGEBF. With respect to the LLNA EC3 value, the best of the alternative monomers had a value approximately 2.5 times higher than those of DGEBA and DGEBF. The diepoxides were reacted with triethylenetetramine, and the polymers formed were tested for technical applicability using thermogravimetric analysis and differential scanning calorimetry. Four out of the six alternative ERMs gave polymers with a thermal stability comparable to that obtained with DGEBA and DGEBF. The use of improved epoxy resin monomers with less skin sensitizing effects is a direct way to tackle the problem of contact allergy to epoxy resin systems, particularly in occupational settings, resulting in a reduction in the incidence of allergic contact dermatitis.

  8. Aggregation processes with catalysis-driven monomer birth/death

    Institute of Scientific and Technical Information of China (English)

    Chen Yu; Han An-Jia; Ke Jian-Hong; Lin Zhen-Quan

    2006-01-01

    We propose two solvable cluster growth models, in which an irreversible aggregation spontaneously occurs between any two clusters of the same species; meanwhile, monomer birth or death of species A occurs with the help of species B. The system with the size-dependent monomer birth/death rate kernel K(i,j) = Jijv is then investigated by means of the mean-field rate equation. The results show that the kinetic scaling behaviour of species A depends crucially on the value of the index v. For the model with catalysis-driven monomer birth, the cluster-mass distribution of species A obeys the conventional scaling law in the v ≤ 0 case, while it satisfies a generalized scaling form in the v>0 case; moreover, the total mass of species A is a nonzero value in the v< 0 case while it grows continuously with time in the v>0 case. For the model with catalysis-driven monomer death, the cluster-mass distribution also approaches the conventional scaling form in the v < 0 case, while the conventional scaling description of the system breaks down in the v ≥ 0 case. Additionally, the total mass of species A retains a nonzero quantity in the v <0 case, but it decreases to zero with time in the v ≥ 0 case.

  9. Base-catalyzed depolymerization of lignin : separation of monomers

    Energy Technology Data Exchange (ETDEWEB)

    Vigneault, A. [Sherbrooke Univ., PQ (Canada). Dept. of Chemical Engineering; Johnson, D.K. [National Renewable Energy Laboratory, Golden, CO (United States); Chornet, E. [Sherbrooke Univ., PQ (Canada). Dept. of Chemical Engineering; National Renewable Energy Laboratory, Golden, CO (United States)

    2007-12-15

    Biofuels produced from residual lignocellulosic biomass range from ethanol to biodiesel. The use of lignin for the production of alternate biofuels and green chemicals has been studied with particular emphasis on the structure of lignin and its oxyaromatic nature. In an effort to fractionate lignocellulosic biomass and valorize specific constitutive fractions, the authors developed a strategy for the separation of 12 added value monomers produced during the hydrolytic base catalyzed depolymerization (BCD) of a Steam Exploded Aspen Lignin. The separation strategy was similar to vanillin purification to obtain pure monomers, but combining more steps after the lignin depolymerization such as acidification, batch liquid-liquid-extraction (LLE), followed by vacuum distillation, liquid chromatography (LC) and crystallization. The purpose was to develop basic data for an industrial size process flow diagram, and to evaluate both the monomer losses during the separation and the energy requirements. Experimentally testing of LLE, vacuum distillation and flash LC in the laboratory showed that batch vacuum distillation produced up to 4 fractions. Process simulation revealed that a series of 4 vacuum distillation columns could produce 5 distinct monomer streams, of which 3 require further chromatography and crystallization operations for purification. 22 refs., 4 tabs., 8 figs.

  10. Influence of the diene monomer on devulcanization of EPDM rubber

    NARCIS (Netherlands)

    Verbruggen, M.; Does, van der L.; Noordermeer, J.W.M.; Duin, van M.

    2008-01-01

    Ethylene–propylene–diene rubbers (EPDM) with 2-ethylidene-5-norbornene (ENB), dicyclopentadiene (DCPD), and 1,4-hexadiene (HD) as third monomers have been vulcanized with peroxide and with a conventional sulfur vulcanization recipe, and their devulcanization was subsequently investigated for recycli

  11. Binding interactions between suberin monomer components and pesticides

    Energy Technology Data Exchange (ETDEWEB)

    Olivella, M.À., E-mail: angels.olivella@udg.edu [Department of Chemical Engineering, Escola Politècnica Superior, Universitat de Girona, Maria Aurèlia Capmany, 61, 17071 Girona (Spain); Bazzicalupi, C.; Bianchi, A. [Department of Chemistry “Ugo Schiff”, University of Florence, Via della Lastruccia, 3, 50019 Sesto Fiorentino (Italy); Río, J.C. del [Instituto de Recursos Naturales y Agrobiología de Sevilla, Consejo Superior de Investigaciones Científicas, P.O. Box 1052, 41080 Seville (Spain); Fiol, N.; Villaescusa, I. [Department of Chemical Engineering, Escola Politècnica Superior, Universitat de Girona, Maria Aurèlia Capmany, 61, 17071 Girona (Spain)

    2015-09-15

    Understanding the role of biomacromolecules and their interactions with pollutants is a key for elucidating the sorption mechanisms and making an accurate assessment of the environmental fate of pollutants. The knowledge of the sorption properties of the different constituents of these biomacromolecules may furnish a significant contribution to this purpose. Suberin is a very abundant biopolymer in higher plants. In this study, suberin monomers isolated from cork were analyzed by thermally-assisted methylation with tetramethylammonium hydroxide (TMAH) in a pyrolysis unit coupled to gas chromatography–mass spectrometry (GC/MS). The isolated monomer mixture was used to study the sorption of three pesticides (isoproturon, methomyl and oxamyl). The modes of pesticide–sorbent interactions were analyzed by means of two modeling calculations, the first one representing only the mixture of suberin monomers used in the sorption study, and the second one including glycerol to the mixture of suberin monomers, as a building block of the suberin molecule. The results indicated that the highest sorption capacity exhibited by the sorbent was for isoproturon (33%) being methomyl and oxamyl sorbed by the main suberin components to a lesser extent (3% and < 1%, respectively). In addition to van der Waals interactions with the apolar region of sorbent and isoproturon, modeling calculations evidenced the formation of a hydrogen bond between the isoproturon NH group and a carboxylic oxygen atom of a suberin monomer. In the case of methomyl and oxamyl only weak van der Waals interactions stabilize the pesticide–sorbent adducts. The presence of glycerol in the model provoked significant changes in the interactions with isoproturon and methomyl. - Highlights: • Suberin has low affinity to retain pesticides of aliphatic character. • Suberin has a moderate affinity to adsorb isoproturon. • Modeling calculations show that apolar portion of suberin interacts with isoproturon.

  12. 5 CFR 330.1104 - Eligibility.

    Science.gov (United States)

    2010-01-01

    ... PLACEMENT (GENERAL) Federal Employment Priority Consideration Program for Displaced Employees of the District of Columbia Department of Corrections § 330.1104 Eligibility. (a) To be eligible for...

  13. Alternate fuels and chemicals from synthesis gas: Vinyl acetate monomer. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Richard D. Colberg; Nick A. Collins; Edwin F. Holcombe; Gerald C. Tustin; Joseph R. Zoeller

    1999-01-01

    There has been a long-standing desire on the part of industry and the U.S. Department of Energy to replace the existing ethylene-based vinyl acetate monomer (VAM) process with an entirely synthesis gas-based process. Although there are a large number of process options for the conversion of synthesis gas to VAM, Eastman Chemical Company undertook an analytical approach, based on known chemical and economic principles, to reduce the potential candidate processes to a select group of eight processes. The critical technologies that would be required for these routes were: (1) the esterification of acetaldehyde (AcH) with ketene to generate VAM, (2) the hydrogenation of ketene to acetaldehyde, (3) the hydrogenation of acetic acid to acetaldehyde, and (4) the reductive carbonylation of methanol to acetaldehyde. This report describes the selection process for the candidate processes, the successful development of the key technologies, and the economic assessments for the preferred routes. In addition, improvements in the conversion of acetic anhydride and acetaldehyde to VAM are discussed. The conclusion from this study is that, with the technology developed in this study, VAM may be produced from synthesis gas, but the cost of production is about 15% higher than the conventional oxidative acetoxylation of ethylene, primarily due to higher capital associated with the synthesis gas-based processes.

  14. Polymer as a function of monomer: Analytical quantum modeling

    CERN Document Server

    Nakhaee, Mohammad

    2016-01-01

    To identify an analytical relation between the properties of polymers and their's monomer a Metal-Molecule-Metal (MMM) junction has been presented as an interesting and widely used object of research in which the molecule is a polymer which is able to conduct charge. The method used in this study is based on the Green's function approach in the tight-binding approximation using basic properties of matrices. For a polymer base MMM system, transmission, density of states (DOS) and local density of states (LDOS) have been calculated as a function of the hamiltonian of the monomer. After that, we have obtained a frequency for LDOS variations in pass from a subunit to the next one which is a function of energy.

  15. Formaldehyde stabilization facilitates lignin monomer production during biomass depolymerization.

    Science.gov (United States)

    Shuai, Li; Amiri, Masoud Talebi; Questell-Santiago, Ydna M; Héroguel, Florent; Li, Yanding; Kim, Hoon; Meilan, Richard; Chapple, Clint; Ralph, John; Luterbacher, Jeremy S

    2016-10-21

    Practical, high-yield lignin depolymerization methods could greatly increase biorefinery productivity and profitability. However, development of these methods is limited by the presence of interunit carbon-carbon bonds within native lignin, and further by formation of such linkages during lignin extraction. We report that adding formaldehyde during biomass pretreatment produces a soluble lignin fraction that can be converted to guaiacyl and syringyl monomers at near theoretical yields during subsequent hydrogenolysis (47 mole % of Klason lignin for beech and 78 mole % for a high-syringyl transgenic poplar). These yields were three to seven times those obtained without formaldehyde, which prevented lignin condensation by forming 1,3-dioxane structures with lignin side-chain hydroxyl groups. By depolymerizing cellulose, hemicelluloses, and lignin separately, monomer yields were between 76 and 90 mole % for these three major biomass fractions. Copyright © 2016, American Association for the Advancement of Science.

  16. Dynamics of Aggregate Growth Through Monomer Birth and Death

    Institute of Scientific and Technical Information of China (English)

    KE Jian-Hong; LIN Zhen-Quan

    2004-01-01

    @@ We investigate the kinetic behaviour of the growth of aggregates through monomer birth and death and propose a simple model with the rate kernels K(k) ∝ ku and K′(k) ∝ kv at which the aggregate Ak of size k respectively yields and loses a monomer. For the symmetrical system with K(k) = K′(k), the aggregate size distribution approaches the conventional scaling form in the case of u < 2, while the system may undergo a gelation-like transition in the u > 2 case. Moreover, the typical aggregate size S(t) grows as t1/(2-u) in the u < 2 case and increases exponentially with time in the u = 2 case. We also investigate several solvable systems with asymmetrical rate kernels and find that the scaling of the aggregate size distribution may break down in most cases.

  17. Syntheses of New Functionalized Monomers for π-Conjugated Polymers

    Institute of Scientific and Technical Information of China (English)

    D.VYPRACHTICKY; V.CIMRO; P.PAVLKOVA; I.KMNEK

    2007-01-01

    1 Results Tailored monomers based on the activated esters of 2,5-dibromobenzoic (sulfonic) acid derivatives, the 3-substituted 2,5-dibromothiophenes, the 9-substituted 2,7-dibromocarbazoles, and on the brominated 1,10-phenanthrolines suitable for Suzuki, Yamamoto or Grignard metathesis (GRIM) coupling reactions were synthesized and characterized by melting point, elemental analysis, 1H NMR, FTIR and TLC. The Horner-Wadsworth-Emmons reaction mechanism was utilized for the preparation of the 3-[2-(pyren-1...

  18. Development of high performance vinyl acetate monomer (VAM) catalysts

    OpenAIRE

    2009-01-01

    The focus of this study was to develop high performance catalysts for the synthesis of vinyl acetate monomer (VAM). By systematic variation of different preparation parameters a multitude of shell catalysts consisting of PdAu nanoparticles supported on a bentonite carrier was explored. In order to investigate the influence of these alterations on catalytic performance, a catalyst classification was accomplished in a high-throughput Temkin test unit by comparison with a highly efficient commer...

  19. Synthesis of a new aromatic dianhydride monomer and related polyimide

    Institute of Scientific and Technical Information of China (English)

    Yun Xia Wei; Ming Guang Ma; Guo Hu Zhao; Sheng Ying Li; Ming Kai Chen

    2009-01-01

    A novel aromatic dianhydride monomer,3,3'-oxybis[(3,4-dicarboxyphenoxy)phenol]dianhydride,was successfully synthe-sized in three steps using 3,3'-oxybis(phenol)as starting material,which was reacted with 4,4'-oxydianiline(ODA)via a conventional thermal or chemical imidization method to produce a new polyimide.The resulting polyimide exhibited excellent solubility,and film-forming capability.

  20. 7 CFR 1230.624 - Eligibility.

    Science.gov (United States)

    2010-01-01

    ... CONSUMER INFORMATION Procedures for the Conduct of Referendum Referendum § 1230.624 Eligibility. (a) Eligible producers and importers. Persons eligible to register and vote in the referendum include: (1... individual who registers to vote in the referendum on behalf of any eligible producer or importer corporation...

  1. 7 CFR 1260.114 - Eligible organization.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Eligible organization. 1260.114 Section 1260.114... Promotion and Research Order Definitions § 1260.114 Eligible organization. Eligible organization means any organization which has been certified by the Secretary pursuant to the Act and this part as being eligible...

  2. 7 CFR 1160.114 - Eligible organization.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 9 2010-01-01 2009-01-01 true Eligible organization. 1160.114 Section 1160.114... Order Definitions § 1160.114 Eligible organization. Eligible organization means an organization eligible... organization pursuant to section 501(c) (3), (5), or (6) of the Internal Revenue Code (26 U.S.C. 501(c) (3),...

  3. Ortho-substituted triptycene-based diamines, monomers, and polymers, methods of making and uses thereof

    KAUST Repository

    Ghanem, Bader Saleh

    2017-04-13

    Described herein are ortho-dimethyl-substituted and tetramethyi-substituted triptycene-containing diamine monomers and microporous triptycene-based poiyimides and poiyamides, and methods of making the monomers and polymers.

  4. Thermally stable drilling fluid additive comprised of a copolymer of catechol-based monomer

    Energy Technology Data Exchange (ETDEWEB)

    Patel, A.D.

    1986-06-17

    A water soluble polymer is described having thermal stability and exhibiting utility as an aqueous drilling fluid additive comprising: (a) a major portion of a catechol based monomer; (b) a minor portion of a dicarboxylic acid monomer.

  5. SYNTHESIS AND CHARACTERIZATION OF A NOVEL STYRYLTHIOPHENE MONOMER AND CORRESPONDING POLYURETHANE FOR NLO MATERIALS

    Institute of Scientific and Technical Information of China (English)

    Jiang-hong Wang; Jian-feng Zhai; Jia-yun Zhou; Yu-xia Zhao; Yu-quan Shen

    1999-01-01

    A novel monomer,(trans)-7-[4-N,N-(di-β-hydroxyethyl) amino-benzene]-ethenyl-3,5-dinitro-thiophene (HBDT), was synthesized and characterized. The details of synthesizing the monomer and prepolymer, polyurethane with the monomer covalently incorporated are presented. The prepolymer and polyurethane exhibited good solubility in common organic solvents. Molecular nonlinear optical properties of the monomer (HBDT) substituted thiophene based stilbenes is presented.

  6. [Migration of monomers and primary aromatic amines from nylon products].

    Science.gov (United States)

    Mutsuga, Motoh; Yamaguchi, Miku; Ohno, Hiroyuki; Kawamura, Yoko

    2010-01-01

    Migration of 2 kinds of monomer and 21 kinds of primary aromatic amines (PAAs) from 21 kinds of nylon products such as turners, ladles and wrap film were determined. Samples were classified as regards materials by mean of pyrolysis-GC/MS. One sample was classified as nylon 6, 15 samples as nylon 66 and three samples as nylon 6/66 copolymers, while two samples were laminate of nylon 6 with polyethylene or polypropylene. All of the nylon 66 samples contained a small amount of ε-caprolactam (CPL), which is the nylon 6 monomer. Migration levels of monomers and PAAs at 60°C for 30 min into 20% ethanol were measured by LC/MS/MS. CPL was detected at the level of 0.015-38 µg/mL from all samples, excluding one wrap film sample, and 1,6-hexamethylenediamine was detected at the level of 0.002-0.013 µg/mL from all nylon 66 samples and one nylon 6/66 sample. In addition, 0.006-4.3 µg/mL of 4,4'-diaminodiphenylmethane from three samples, 0.032-0.23 µg/mL of aniline from four samples, 0.001 µg/mL of 4-chloroaniline from two samples, and 0.002 µg/mL of 2-toluidine and 0.066 mg/mL of 1-naphthylamine from one sample each were detected. The migration levels at 95 or 121°C were about 3 and 10 times the 60°C levels, respectively.

  7. Recovery of Monomer from Nylon waste powder for its Recycling

    Directory of Open Access Journals (Sweden)

    Dilip B.Patil

    2014-03-01

    Full Text Available Recovery of monomer hexamethylene diamine(HMD in the form of dibenzoyl derivative of hexamethylene diamine (DBHMD from Nylon waste rope powder was carried out by degradation of Nylon waste powder of nylon rope waste.The molecular weight of nylon waste powder was found to be 26582.The minimum amount of nylon waste powder and hydrochloric acid required for maximum recovery of HMD and DBHMD was found to be 5g and 5N,50ml hydrochloric acid respectively. Further it was observed that the maximum time and temperature required for getting maximum yield of DBHMD was 120 minutes and 800C respectively.

  8. Folding Landscape of Mutant Huntingtin Exon1: Diffusible Multimers, Oligomers and Fibrils, and No Detectable Monomer.

    Directory of Open Access Journals (Sweden)

    Bankanidhi Sahoo

    Full Text Available Expansion of the polyglutamine (polyQ track of the Huntingtin (HTT protein above 36 is associated with a sharply enhanced risk of Huntington's disease (HD. Although there is general agreement that HTT toxicity resides primarily in N-terminal fragments such as the HTT exon1 protein, there is no consensus on the nature of the physical states of HTT exon1 that are induced by polyQ expansion, nor on which of these states might be responsible for toxicity. One hypothesis is that polyQ expansion induces an alternative, toxic conformation in the HTT exon1 monomer. Alternative hypotheses posit that the toxic species is one of several possible aggregated states. Defining the nature of the toxic species is particularly challenging because of facile interconversion between physical states as well as challenges to identifying these states, especially in vivo. Here we describe the use of fluorescence correlation spectroscopy (FCS to characterize the detailed time and repeat length dependent self-association of HTT exon1-like fragments both with chemically synthesized peptides in vitro and with cell-produced proteins in extracts and in living cells. We find that, in vitro, mutant HTT exon1 peptides engage in polyQ repeat length dependent dimer and tetramer formation, followed by time dependent formation of diffusible spherical and fibrillar oligomers and finally by larger, sedimentable amyloid fibrils. For expanded polyQ HTT exon1 expressed in PC12 cells, monomers are absent, with tetramers being the smallest molecular form detected, followed in the incubation time course by small, diffusible aggregates at 6-9 hours and larger, sedimentable aggregates that begin to build up at 12 hrs. In these cell cultures, significant nuclear DNA damage appears by 6 hours, followed at later times by caspase 3 induction, mitochondrial dysfunction, and cell death. Our data thus defines limits on the sizes and concentrations of different physical states of HTT exon1 along the

  9. Comparison of monofunctional and multifunctional monomers in phosphate binding molecularly imprinted polymers.

    Science.gov (United States)

    Wu, Xiangyang; Goswami, Kisholoy; Shimizu, Ken D

    2008-01-01

    In this study, molecularly imprinted polymers (MIPs) prepared using a multifunctional and a monofunctional monomer were compared with respect to their affinities, selectivities, and imprinting efficiencies for organophosphates. This is of interest because multifunctional monomers have higher affinities than traditional monofunctional monomers for their target analytes and thus should yield MIPs with higher affinities and selectivities. However, polymers containing multifunctional monomer may also have a higher number of unselective, non-templated binding sites. This increase in background binding sites could lead to a decrease in the magnitude of the imprinting effect and in the selectivity of the MIP. Therefore, phosphate selective imprinted and non-imprinted polymers (NIPs) were prepared using a novel multifunctional triurea monomer. The binding properties of these polymers were compared with polymers prepared using a monofunctional monourea monomer. The binding affinities and selectivities of the monomers, imprinted polymers, and NIPs were characterized by NMR titration, binding uptake studies, and binding isotherms. MIPs prepared with the triurea monomer showed higher binding affinity and selectivity for the diphenylphosphate anion in organic solvents than the MIPs prepared with the monofunctional monomer. Surprisingly, the binding properties of the NIPs revealed that the polymers prepared using the multifunctional and monofunctional monomers were very similar in affinity and selectivity. Thus, the multifunctional monomers increase not only the affinity of the MIP but also enhance the imprinting effect.

  10. Synthesis of acrylic and allylic bifunctional cross-linking monomers derived from PET waste

    Science.gov (United States)

    Cruz-Aguilar, A.; Herrera-González, A. M.; Vázquez-García, R. A.; Navarro-Rodríguez, D.; Coreño, J.

    2013-06-01

    An acrylic and two novel allylic monomers synthesized from bis (hydroxyethyl) terephthalate, BHET, are reported. This was obtained by glycolysis of post-consumer PET with boiling ethylene glycol. The bifunctional monomer bis(2-(acryloyloxy)ethyl) terephthalate was obtained from acryloyl chloride, while the allylic monomers 2-(((allyloxi)carbonyl)oxy) ethyl (2-hydroxyethyl) terephthalate and bis(2-(((allyloxi)carbonyl)oxy)ethyl) terephthalate, from allyl chloroformate. Cross-linking was studied in bulk polymerization using two different thermal initiators. Monomers were analyzed by means of 1H NMR and the cross-linked polymers by infrared spectroscopy. Gel content higher than 90% was obtained for the acrylic monomer. In the case of the mixture of the allylic monomers, the cross-linked polymer was 80 % using BPO initiator, being this mixture 24 times less reactive than the acrylic monomer.

  11. Primary and Presidential Candidates

    DEFF Research Database (Denmark)

    Goddard, Joseph

    2012-01-01

    This article looks at primary and presidential candidates in 2008 and 2012. Evidence suggests that voters are less influenced by candidates’ color, gender, or religious observation than previously. Conversely, markers of difference remain salient in the imaginations of pollsters and journalists...

  12. Effects of acrylic resin monomers on porcine coronary artery reactivity.

    Science.gov (United States)

    Abebe, Worku; West, Daniel; Rueggeberg, Frederick A; Pashley, David; Mozaffari, Mahmood S

    2016-07-01

    The purpose of the present investigation was to assess the reactivity of porcine coronary arteries under in vitro conditions following their exposure to methyl methacrylate (MMA) and hydroxyethyl methacrylate (HEMA) monomers. Confirming previous studies using rat aortas, both MMA and HEMA induced acute/direct relaxation of coronary ring preparations, which was partly dependent on the endothelium. With prolonged tissue exposure, both monomers caused time- and concentration-dependent inhibition of receptor-mediated contraction of the vascular smooth muscle caused by prostaglandin F2∝ (PGF2∝), with HEMA causing more inhibition than MMA. Hydroxyethyl methacrylate, but not MMA, also produced impairment of non-receptor-mediated contraction of the coronary smooth muscle induced by KCl. On the other hand, neither HEMA nor MMA altered relaxation of the smooth muscle produced by the direct-acting pharmacological agent, sodium nitroprusside (SNP). While exposure to HEMA impaired endothelium-dependent vasorelaxation caused by bradykinin (BK), MMA markedly enhanced this endothelial-mediated response of the arteries. The enhanced endothelial response produced by MMA was linked to nitric oxide (NO) release. In conclusion, with prolonged tissue exposure, MMA causes less pronounced effects/adverse consequences on coronary smooth muscle function relative to the effect of HEMA, while enhancing vasorelaxation associated with release of NO from the endothelium. Accordingly, MMA-containing resin materials appear to be safer for human applications than materials containing HEMA.

  13. Wet air oxidation of epoxy acrylate monomer industrial wastewater.

    Science.gov (United States)

    Yang, Shaoxia; Liu, Zhengqian; Huang, Xiaohui; Zhang, Beiping

    2010-06-15

    Epoxy acrylate monomer industrial wastewater contained highly concentrated and toxic organic compounds. The wet air oxidation (WAO) and catalytic wet air oxidation (CWAO) were used to eliminate pollutants in order to examine the feasibility of the WAO/CWAO as a pre-treatment method for the industrial wastewater. The results showed that in the WAO 63% chemical oxygen demand (COD) and 41% total organic carbon (TOC) removals were achieved and biological oxygen demand (BOD(5))/COD ratio increased from 0.13 to 0.72 after 3h reaction at 250 degrees C, 3.5MPa and the initial concentration of 100g(COD)/L. Among homogenous catalysts (Cu(2+), Fe(2+), Fe(3+) and Mn(2+) salts), Cu(2+) salt exhibited better performance. CuO catalyst was used in the CWAO of the wastewater, COD and TOC conversion were 77 and 54%, and good biodegradability was achieved. The results proved that the CWAO was an effective pre-treatment method for the epoxy acrylate monomer industrial wastewater.

  14. Shelf Life of PMR Polyimide Monomer Solutions and Prepregs Extended

    Science.gov (United States)

    Alston, William B.; Scheiman, Daniel A.

    2000-01-01

    PMR (Polymerization of Monomeric Reactants) technology was developed in the mid-1970's at the NASA Glenn Research Center at Lewis Field for fabricating high-temperature stable polyimide composites. This technology allowed a solution of polyimide monomers or prepreg (a fiber, such as glass or graphite, impregnated with PMR polyimide monomers) to be thermally cured without the release of volatiles that cause the formation of voids unlike the non-PMR technology used for polyimide condensation type resins. The initial PMR resin introduced as PMR 15 is still commercially available and is used worldwide by aerospace industries as the state-of-the-art resin for high-temperature polyimide composite applications. PMR 15 offers easy composite processing, excellent composite mechanical property retention, a long lifetime at use temperatures of 500 to 550 F, and relatively low cost. Later, second-generation PMR resin versions, such as PMR II 50 and VCAP 75, offer improvements in the upper-use temperature (to 700 F) and in the useful life at temperature without major compromises in processing and property retention but with significant increases in resin cost. Newer versions of nontoxic (non-methylene dianiline) PMR resins, such as BAX PMR 15, offer similar advantages as originally found for PMR 15 but also with significant increases in resin cost. Thus, the current scope of the entire PMR technology available meets a wide range of aeronautical requirements for polymer composite applications.

  15. Effect of cationic monomer on properties of fluorinated acrylate latex

    Institute of Scientific and Technical Information of China (English)

    Li Jun Chen

    2012-01-01

    Cationic fluorinated acrylate latex was prepared via semi-continuous emulsion copolymerization of cationic monomer and other monomers.The resultant latex and its film were characterized with dynamic light scattering detector and contact angle meter.Influences of amount of DMDAAC on the properties of resultant latex and its film were investigated in detail.Results show that the particle size of the latex has the minimum value and the zeta potential of the latex is increased when the amount of DMDAAC is increased.In addition,the particle size of the latex is unimodal distribution when the amount of DMDAAC is not more than 2.5%.However,the particle size of the latex is bimodal distribution when the amount of DMDAAC is more than 2.5%.The contact angle is varied slightly with the increase of amount of DMDAAC when it is not more than 2.5%.Nevertheless,the contact angle is decreased with the increase of the amount of DMDAAC when it is more than 25%.

  16. Induced DNA damage by dental resin monomers in somatic cells.

    Science.gov (United States)

    Arossi, Guilherme Anziliero; Lehmann, Mauricio; Dihl, Rafael Rodrigues; Reguly, Maria Luiza; de Andrade, Heloisa Helena Rodrigues

    2010-02-01

    The present in vivo study investigated the genotoxicity of four dental resin monomers: triethyleneglycoldimethacrylate (TEGDMA), hydroxyethylmethacrylate (HEMA), urethanedimethacrylate (UDMA) and bisphenol A-glycidylmethacrylate (BisGMA). The Somatic Mutation and Recombination Test (SMART) in Drosophila melanogaster was applied to analyse their genotoxicity expressed as homologous mitotic recombination, point and chromosomal mutation. SMART detects the loss of heterozygosity of marker genes expressed phenotypically on the fly's wings. This fruit fly has an extensive genetic homology to mammalians, which makes it a suitable model organism for genotoxic investigations. The present findings provide evidence that the mechanistic basis underlying the genotoxicity of UDMA and TEGDMA is related to homologous recombination and gene/chromosomal mutation. A genotoxic pattern can correspondingly be discerned for both UDMA and TEGDMA: their genotoxicity is attributed respectively to 49% and 44% of mitotic recombination, as well as 51% and 56% of mutational events, including point and chromosomal alterations. The monomer UDMA is 1.6 times more active than TEGDMA to induce mutant clones per treatment unit. BisGMA and HEMA had no statistically significant effect on total spot frequencies - suggesting no genotoxic action in the SMART assay. The clinical significance of these observations has to be interpreted for data obtained in other bioassays.

  17. The Kinetics of Cellulose Grafting with Vinyl Acetate Monomer

    Directory of Open Access Journals (Sweden)

    Éva Borbély

    2005-11-01

    Full Text Available Cellulose is a natural raw material recurring in a great quantity. The demand touse it more and more widely is increasing. The production of cellulose derivates started asearly as the 19th century, however the modification of these materials meant the breakingup the fibrous structure, which made their use more difficult in paper industry. Themodified cellulose made by graft copolymerization, however, keeps its fibrous character,which provides a great advantage regarding its use. Grafting of industrial cellulose pulpwith vinyl-acetate allows for the production of grafted wood cellulose fibres that have athermoplastic layer on their surface. The binder fibre (fibrid produced in this way can beexcellently used for producing synthetic papers.In the first part of my experiments I dealt with choosing the parameters of graftcopolymerization which are best suited to various uses and after that I studied thedependence of graft reaction on the composition and properties of industrial celluloseapplied. The selection of the suitable reaction parameters was followed by the study ofreaction speed and activation energy. I have stated that the gross reaction of graftingindustrial cellulose with vinyl-acetate monomer is a second order reaction, which is provenby the fact that the invert of the momentary monomer concentration of the system plottedagainst time is a linear function. The rise of the curves, that is, the reaction speed increaseswhen the temperature in the range of 293–323 K is increasing, while the average activationenergy decreases.

  18. Enhancing reuse of structured eligibility criteria and supporting their relaxation.

    Science.gov (United States)

    Milian, Krystyna; Hoekstra, Rinke; Bucur, Anca; Ten Teije, Annette; van Harmelen, Frank; Paulissen, John

    2015-08-01

    Patient recruitment is one of the most important barriers to successful completion of clinical trials and thus to obtaining evidence about new methods for prevention, diagnostics and treatment. The reason is that recruitment is effort consuming. It requires the identification of candidate patients for the trial (the population under study), and verifying for each patient whether the eligibility criteria are met. The work we describe in this paper aims to support the comparison of population under study in different trials, and the design of eligibility criteria for new trials. We do this by introducing structured eligibility criteria, that enhance reuse of criteria across trials. We developed a method that allows for automated structuring of criteria from text. Additionally, structured eligibility criteria allow us to propose suggestions for relaxation of criteria to remove potentially unnecessarily restrictive conditions. We thereby increase the recruitment potential and generalizability of a trial. Our method for automated structuring of criteria enables us to identify related conditions and to compare their restrictiveness. The comparison is based on the general meaning of criteria, comprised of commonly occurring contextual patterns, medical concepts and constraining values. These are automatically identified using our pattern detection algorithm, state of the art ontology annotators and semantic taggers. The comparison uses predefined relations between the patterns, concept equivalences defined in medical ontologies, and threshold values. The result is a library of structured eligibility criteria which can be browsed using fine grained queries. Furthermore, we developed visualizations for the library that enable intuitive navigation of relations between trials, criteria and concepts. These visualizations expose interesting co-occurrences and correlations, potentially enhancing meta-research. The method for criteria structuring processes only certain types of

  19. 7 CFR 249.6 - Participant eligibility.

    Science.gov (United States)

    2010-01-01

    ... Agriculture Regulations of the Department of Agriculture (Continued) FOOD AND NUTRITION SERVICE, DEPARTMENT OF AGRICULTURE CHILD NUTRITION PROGRAMS SENIOR FARMERS' MARKET NUTRITION PROGRAM (SFMNP) Participant Eligibility... congregate nutrition services are provided, as categorically eligible to receive SFMNP benefits....

  20. 7 CFR 1599.3 - Eligibility determination.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Eligibility determination. 1599.3 Section 1599.3 Agriculture Regulations of the Department of Agriculture (Continued) FOREIGN AGRICULTURAL SERVICE, DEPARTMENT... Eligibility determination. (a) An entity will be eligible to become a participant only after FAS determines...

  1. 7 CFR 22.302 - Area eligibility.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Area eligibility. 22.302 Section 22.302 Agriculture Office of the Secretary of Agriculture RURAL DEVELOPMENT COORDINATION Roles and Responsibilities of State Governments § 22.302 Area eligibility. Eligibility for programs under the Act will be based on the criteria of...

  2. 38 CFR 21.3040 - Eligibility; child.

    Science.gov (United States)

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Eligibility; child. 21.3040 Section 21.3040 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS (CONTINUED.... Chapter 35 Eligibility and Entitlement § 21.3040 Eligibility; child. (a) Commencement. A program...

  3. 7 CFR 1434.5 - Eligible honey.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Eligible honey. 1434.5 Section 1434.5 Agriculture... FOR HONEY § 1434.5 Eligible honey. To be eligible for a loan, the honey must: (a) Have been produced... merchantable quality deemed by CCC to be suitable for loan; that is, the honey: (1) Is not adulterated; (2)...

  4. 7 CFR 1739.11 - Eligible project.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 11 2010-01-01 2010-01-01 false Eligible project. 1739.11 Section 1739.11 Agriculture... BROADBAND GRANT PROGRAM Community Connect Grant Program § 1739.11 Eligible project. To be eligible for a grant, the Project must: (a) Serve a Rural Area where Broadband Transmission Service does not...

  5. 23 CFR 650.405 - Eligible projects.

    Science.gov (United States)

    2010-04-01

    ..., STRUCTURES, AND HYDRAULICS Highway Bridge Replacement and Rehabilitation Program § 650.405 Eligible projects... rehabilitation. (b) Types of projects which are eligible. The following types of work are eligible for participation in the Highway Bridge Replacement and Rehabilitation Program (HBRRP), hereinafter known as...

  6. 47 CFR 90.33 - General eligibility.

    Science.gov (United States)

    2010-10-01

    ... Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Industrial/Business Radio Pool § 90.33 General eligibility. (a) In addition to the eligibility shown in the Industrial/Business Pool, eligibility is also provided for any corporation...

  7. 7 CFR 1150.108 - Eligible organization.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 9 2010-01-01 2009-01-01 true Eligible organization. 1150.108 Section 1150.108 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing... Order Definitions § 1150.108 Eligible organization. Eligible organization means any organization...

  8. 7 CFR 1250.313 - Eligible organization.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Eligible organization. 1250.313 Section 1250.313... Research and Promotion Order Definitions § 1250.313 Eligible organization. Eligible organization means any organization, association, or cooperative which represents egg producers of any egg producing area of...

  9. 7 CFR 1220.109 - Eligible organization.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Eligible organization. 1220.109 Section 1220.109... CONSUMER INFORMATION Soybean Promotion and Research Order Definitions § 1220.109 Eligible organization. The term eligible organization means any organization which has been certified by the Secretary pursuant...

  10. Polymerization of Polar Monomers from a Theoretical Perspective

    KAUST Repository

    Alghamdi, Miasser

    2016-10-11

    Density functional theory calculations have been used to investigate catalytic mechanism of polymer formation containing polar groups, from the synthesis of the monomer to the synthesis of the macromolecule. In the spirit of a sustainable and green chemistry, we initially focused attention on the coupling of CO2 as economically convenient and recyclable C1 source with C2H4 to form acrylate and/or butirro-lactone, two important polar monomers. In this process formation of a mettallolactone via oxidative coupling of CO2 and C2H4 is an important intermediate. Given this background, we explored in detail (chapter-3) several Ni based catalysts for CO2 coupling with C2H4 to form acrylate. In this thesis we report on the competitive reaction mechanisms (inner vs outer sphere) for the oxidative coupling of CO2 and ethylene for a set of 11 Ni-based complexes containing bisphosphine ligands. In another effort, considering incorporation of a C=C bond into a metal-oxygen-Functional-Group moiety is a challenging step in several polymerization reactions, we explored the details of this reaction (chapter4) using two different catalysts that are capable to perform this reaction in the synthesis of heterocycles. Specifically, the [Rh]-catalyzed intramolecular alkoxyacylation ([Rh] = [RhI(dppp)+] (dppp, 1,3-Bis-diphenylphosphino-propane), and the [Pd]/BPh3 intramolecular alkoxyfunctionalizations. Rest of the thesis we worked on understanding the details of the polymerization of polar monomers using organocatalysts based on N-heterocyclic carbenes (NHC) or N-heterocyclic olefins (NHO). In particular (chapter-5) we studied the polymerization of N-methyl N-carboxy- anhydrides, towards cyclic poly(N-substituted glycine)s, promoted by NHC catalysts. In good agreement with the experimental findings, we demonstrated that NHC promoted ring opening polymerization of N-Me N-Carboxyanhydrides may proceed via two different catalytic pathways. In a similar effort we studied polymerization of

  11. Pilot Candidate Selection

    Science.gov (United States)

    1989-05-01

    pilot selection system and to best support up-front track selection for SUPT? Assumptions The USAF Trainer Masterplan does not include a plan to...replace the T-41 with a new flight screening aircraft. In addition, the Masterplan states that candidates will be track selected prior to entry into primary...training. (3:10) While the Masterplan is not a static document and aircraft procurement plans and/or the timing of track selection are subject to

  12. Polymerization of nonfood biomass-derived monomers to sustainable polymers.

    Science.gov (United States)

    Zhang, Yuetao; Chen, Eugene Y-X

    2014-01-01

    The development of sustainable routes to fine chemicals, liquid fuels, and polymeric materials from natural resources has attracted significant attention from academia, industry, the general public, and governments owing to dwindling fossil resources, surging energy demand, global warming concerns, and other environmental problems. Cellulosic material, such as grasses, trees, corn stover, or wheat straw, is the most abundant nonfood renewable biomass resources on earth. Such annually renewable material can potentially meet our future needs with a low carbon footprint if it can be efficiently converted into fuels, value added chemicals, or polymeric materials. This chapter focuses on various renewable monomers derived directly from cellulose or cellulose platforms and corresponding sustainable polymers or copolymers produced therefrom. Recent advances related to the polymerization processes and the properties of novel biomass-derived polymers are also reviewed and discussed.

  13. Biosynthesis of monomers for plastics from renewable oils.

    Science.gov (United States)

    Lu, Wenhua; Ness, Jon E; Xie, Wenchun; Zhang, Xiaoyan; Minshull, Jeremy; Gross, Richard A

    2010-11-03

    Omega-hydroxyfatty acids are excellent monomers for synthesizing a unique family of polyethylene-like biobased plastics. However, ω-hydroxyfatty acids are difficult and expensive to prepare by traditional organic synthesis, precluding their use in commodity materials. Here we report the engineering of a strain of the diploid yeast Candida tropicalis to produce commercially viable yields of ω-hydroxyfatty acids. To develop the strain we identified and eliminated 16 genes encoding 6 cytochrome P450s, 4 fatty alcohol oxidases, and 6 alcohol dehydrogenases from the C. tropicalis genome. We also show that fatty acids with different chain lengths and degrees of unsaturation can be more efficiently oxidized by expressing different P450s within this strain background. Biocatalysis using engineered C. tropicalis is thus a potentially attractive biocatalytic platform for producing commodity chemicals from renewable resources.

  14. Production and monomer composition of exopolysaccharides by yogurt starter cultures.

    Science.gov (United States)

    Frengova, G I; Simova, E D; Beshkova, D M; Simov, Z I

    2000-12-01

    As components of starter cultures for Bulgarian yogurt, Streptococcus salivarius subsp. thermophilus and Lactobacillus delbrueckii subsp. bulgaricus revealed extensive exopolysaccharide (EPS) production activity when cultivated in whole cow's milk. The polymer-forming activity of thermophilic streptococci was lower (230-270 mg EPS/L) than that of the lactobacilli (400-540 mg EPS/L). Mixed cultures stimulated EPS production in yogurt manufacture, and a maximum concentration of 720-860 mg EPS/L was recorded after full coagulation of milk. The monomer structure of the exopolysaccharides formed by the yogurt starter cultures principally consists of galactose and glucose (1:1), with small amounts of xylose, arabinose, and/or mannose.

  15. Biobased Epoxy Nanocomposites Derived from Lignin-Based Monomers.

    Science.gov (United States)

    Zhao, Shou; Abu-Omar, Mahdi M

    2015-07-13

    Biobased epoxy nanocomposites were synthesized based on 2-methoxy-4-propylphenol (dihydroeugenol, DHE), a molecule that has been obtained from the lignin component of biomass. To increase the content of hydroxyl groups, DHE was o-demethylated using aqueous HBr to yield propylcatechol (DHEO), which was subsequently glycidylated to epoxy monomer. Optimal conditions in terms of yield and epoxy equivalent weight were found to be 60 °C with equal NaOH/phenolic hydroxyl molar ratio. The structural evolution from DHE to cured epoxy was followed by (1)H NMR and Fourier transform infrared spectroscopy. The nano-montmorillonite modified DHEO epoxy exhibited improved storage modulus and thermal stability as determined from dynamic mechanical analysis and thermogravimetric analysis. This study widens the synthesis routes of biobased epoxy thermosets from lignin-based molecules.

  16. Exposing Differences in Monomer Exchange Rates of Multicomponent Supramolecular Polymers in Water.

    Science.gov (United States)

    Baker, Matthew B; Gosens, Ronald P J; Albertazzi, Lorenzo; Matsumoto, Nicholas M; Palmans, Anja R A; Meijer, E W

    2016-02-02

    The formation of multicomponent and bioactive supramolecular polymers is a promising strategy for the formation of biomaterials that match the dynamic and responsive nature of biological systems. In order to fully realize the potential of this strategy, knowledge of the location and behavior of bioactive components within the system is crucial. By employing synthetic strategies to create multifunctional monomers, coupled with FRET and STORM techniques, we have investigated the formation and behavior of a bioactive and multicomponent supramolecular polymer. By creating a peptide-dye-monomer conjugate, we were able to measure high degrees of monomer incorporation and to visualize the equal distribution of monomers within the supramolecular polymer. Furthermore, by tracking the movement of monomers, we uncovered small differences in the dynamics of the bioactive monomers.

  17. Use of Monomer Fraction Data in the Parametrization of Association Theories

    DEFF Research Database (Denmark)

    Kontogeorgis, Georgios; Tsivintzelis, Ioannis; von Solms, Nicolas;

    2010-01-01

    “improved” model parameters can be obtained if monomer fraction data are included in the parameter estimation together with vapor pressures and liquid densities. The expression “improved” implies parameters which can represent several pure compound properties as well as monomer fraction data for pure......, liquid densities and monomer fractions of water and alcohols. The 4C scheme is the best choice for water, while for methanol there is small difference between the 2B and 3B association schemes....

  18. Enzymatic Specific Production and Chemical Functionalization of Phenylpropanone Platform Monomers from Lignin

    OpenAIRE

    Ohta, Yukari; Hasegawa, Ryoichi; Kurosawa, Kanako; Maeda, Allyn H.; Koizumi, Toshio; Nishimura,Hiroshi; Okada, Hitomi; Qu, Chen; Saito, Kaori; Watanabe, Takashi; Hatada, Yuji

    2016-01-01

    Abstract Enzymatic catalysis is an ecofriendly strategy for the production of high‐value low‐molecular‐weight aromatic compounds from lignin. Although well‐definable aromatic monomers have been obtained from synthetic lignin‐model dimers, enzymatic‐selective synthesis of platform monomers from natural lignin has not been accomplished. In this study, we successfully achieved highly specific synthesis of aromatic monomers with a phenylpropane structure directly from natural lignin using a casca...

  19. Glassy dynamics of model colloidal polymers: The effect of "monomer" size

    Science.gov (United States)

    Li, Jian; Zhang, Bo-kai; Li, Hui-shu; Chen, Kang; Tian, Wen-de; Tong, Pei-qing

    2016-05-01

    In recent years, attempts have been made to assemble colloidal particles into chains, which are termed "colloidal polymers." An apparent difference between molecular and colloidal polymers is the "monomer" size. Here, we propose a model to represent the variation from molecular polymer to colloidal polymer and study the quantitative differences in their glassy dynamics. For chains, two incompatible local length scales, i.e., monomer size and bond length, are manifested in the radial distribution function and intramolecular correlation function. The mean square displacement of monomers exhibits Rouse-like sub-diffusion at intermediate time/length scale and the corresponding exponent depends on the volume fraction and the monomer size. We find that the threshold volume fraction at which the caging regime emerges can be used as a rescaling unit so that the data of localization length versus volume fraction for different monomer sizes can gather close to an exponential curve. The increase of monomer size effectively increases the hardness of monomers and thus makes the colloidal polymers vitrify at lower volume fraction. Static and dynamic equivalences between colloidal polymers of different monomer sizes have been discussed. In the case of having the same peak time of the non-Gaussian parameter, the motion of monomers of larger size is much less non-Gaussian. The mode-coupling critical exponents for colloidal polymers are in agreement with that of flexible bead-spring chains.

  20. Studies on the Influence of Monomers on the Performance Properties of Epoxy Acrylate Resin

    Directory of Open Access Journals (Sweden)

    Amrita Sharma

    2008-01-01

    Full Text Available Twelve blend samples were prepared by physical mixing of epoxy acrylate resins with various monomers viz. ethoxylated phenol monoacrylate (EOPA, tripropylene glycol diacrylate (TPGDA and trimethylol propane tri acrylate(TMPTA, having weight ratio of epoxy acrylate resin and monomers are 50:50, 60:40, 70:30, 80:20. These samples were cured under UV radiation using 5% photo initiator by weight. These blends were evaluated for mechanical, chemical & thermal properties. It was found that the sample having mono & tri functional monomers shows better properties than the samples having di functional monomer.

  1. Influence of template/functional monomer/cross‐linking monomer ratio on particle size and binding properties of molecularly imprinted nanoparticles

    DEFF Research Database (Denmark)

    Yoshimatsu, Keiichi; Yamazaki, Tomohiko; Chronakis, Ioannis S.

    2012-01-01

    A series of molecularly imprinted polymer nanoparticles have been synthesized employing various template/functional monomer/crosslinking monomer ratio and characterized in detail to elucidate the correlation between the synthetic conditions used and the properties (e.g., particle size and template...... tuning of particle size and binding properties are required to fit practical applications. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012...

  2. Dark Matter Candidates

    Energy Technology Data Exchange (ETDEWEB)

    Baltz, E.

    2004-12-03

    It is now widely accepted that most of mass-energy in the universe is unobserved except by its gravitational effects. Baryons make only about 4% of the total, with ''dark matter'' making up about 23% and the ''dark energy'' responsible for the accelerated expansion of the universe making up the remainder. We focus on the dark matter, which is the primary constituent of galaxies. We outline the observed properties of this material, enumerating some candidates covering 90 orders of magnitude in mass. Finally, we argue that the weak scale (100 GeV) is relevant to new physics, including the dark matter problem.

  3. Therapeutic Application of Natural Medicine Monomers in Cancer Treatment.

    Science.gov (United States)

    Zhong, Chen; Wall, Nathan R; Zu, Yuangang; Sui, Guangchao

    2017-07-14

    Natural medicine monomers (NMMs) isolated from plants have been recognized for their roles in treating different human diseases including cancers. Many NMMs exhibit effective anti-cancer activities and can be used as drugs or adjuvant agents to enhance the efficacy of chemotherapy and radiotherapy with low or tolerable side effects. Some NMMs, such as Paclitaxel and Camptothecin, have been extensively studied for decades and are now used as anti-cancer medicines due to their remarkable curative effects, such as inhibiting cancer cell proliferation and metastasis, and inducing cell death and differentiation. Although therapeutic effects for most NMMs have been appreciated, the underlying mechanisms of their anti-cancer activities remain largely unexplored. In this review, we have grouped NMMs into six categories based on their chemical structures, and summarized current knowledge of molecular mechanisms of anti-cancer activities to provide a theoretical basis for clinical application and new drug development of NMMs. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  4. Conformational study of neutral histamine monomer and their vibrational spectra

    Science.gov (United States)

    Mukherjee, V.; Yadav, T.

    2016-08-01

    Molecular modeling and potential energy scanning of histamine molecule, which is an important neurotransmitter, with respect to the dihedral angle of methylamine side chain have done which prefer three different conformers of histamine monomer. We have calculated molecular structures and vibrational spectra with IR and Raman intensities of these conformers using Density Functional Theory (DFT) with the exchange functional B3LYP incorporated with the basis set 6-31 ++G(d,p) and Hartree-Fock (HF) with the same basis set. We have also employed normal coordinate analysis (NCA) to scale the theoretical frequencies and to calculate potential energy distributions (PEDs) for the conspicuous assignments. Normal modes assignments of some of the vibrational frequencies of all the three conformers are in good agreement with the earlier reported experimental frequencies of histamine whereas others have modified. The standard deviations between the theoretical and experimental frequencies fall in the region 13-20 cm- 1 for the three conformers. NBO analyses of histamine conformers were also performed. The net charge transfers from ethylamine side chain to the imidazole ring. The intensive interactions between bonding and anti-bonding orbitals are found in imidazole ring. The HOMO-LUMO energy gap is nearly 5.50 eV.

  5. Ligustrazine monomer against cerebral ischemia-reperfusion injury

    Directory of Open Access Journals (Sweden)

    Hai-jun Gao

    2015-01-01

    Full Text Available Ligustrazine (2,3,5,6-tetramethylpyrazine is a major active ingredient of the Szechwan lovage rhizome and is extensively used in treatment of ischemic cerebrovascular disease. The mechanism of action of ligustrazine use against ischemic cerebrovascular diseases remains unclear at present. This study summarizes its protective effect, the optimum time window of administration, and the most effective mode of administration for clinical treatment of cerebral ischemia/reperfusion injury. We examine the effects of ligustrazine on suppressing excitatory amino acid release, promoting migration, differentiation and proliferation of endogenous neural stem cells. We also looked at its effects on angiogenesis and how it inhibits thrombosis, the inflammatory response, and apoptosis after cerebral ischemia. We consider that ligustrazine gives noticeable protection from cerebral ischemia/reperfusion injury. The time window of ligustrazine administration is limited. The protective effect and time window of a series of derivative monomers of ligustrazine such as 2-[(1,1-dimethylethyloxidoimino]methyl]-3,5,6-trimethylpyrazine, CXC137 and CXC195 after cerebral ischemia were better than ligustrazine.

  6. Rheological study of polypropylene irradiated with polyfunctional monomers

    Science.gov (United States)

    Otaguro, H.; Rogero, S. O.; Yoshiga, A.; Lima, L. F. C. P.; Parra, D. F.; Artel, B. W. H.; Lugão, A. B.

    2007-12-01

    The aim of this paper is to investigate the rheological properties of polypropylene (PP) modified by ionization radiation (gamma rays) in the presence of two different monomers. The samples were mixed in a twin-screw extruder with ethylene glycol dimethacrylate (EGDMA) or trimethylolpropane trimethacrylate (TMPTMA) with concentration in the range of 0.5-5.0 mmol. After that, they were irradiated with 20 kGy dose of gamma radiation. The structural modification of polypropylene was analyzed in the melt state by measuring melt flow rate (MFR), η* (complex viscosity) and G' (storage modulus) in the angular frequency range of 10 -1 to 3 × 10 2 rad s -1. From the oscillatory rheology data, one could obtain the values of η0 (zero shear viscosity) that would be related to the molar mass. All results were discussed with respect to the crosslinking and degradation process that occur in the post-reactor treatment to produce controlled rheology polypropylene. The resulting polymeric materials were submitted the cytotoxicity in vitro test by neutral red uptake methodology with NCTC L 929 cell line from American Type Culture Collection bank. All modified PP samples presented no cytotoxicity.

  7. Blood compatibility of polyurethane surface grafted copolymerization with sulfobetaine monomer.

    Science.gov (United States)

    Jiang, Yuan; Rongbing, Bian; Ling, Tong; Jian, Shen; Sicong, Lin

    2004-07-01

    Surface modification is an effective way to improve the hemocompatibility and remain bulk properties of biomaterials. Recently, polymer tailed with zwitterions was found having good blood compatibility. In this study, the grafting copolymerization of sulfobetaine onto polyurethane surface was obtained through two steps. In the first step, polyurethane film coupled with vinyl groups was obtained through the reaction between the carboxyl group of acrylic acid (AA) and the NH-urethane group of polyurethane by dicyclohexylcarbodiimide (DCC). In the second step, sulfobetaine was grafted copolymerization on the surface using AIBN as an initiator. The reaction process was monitored with ATR-IR spectra and X-ray photoelectron spectroscopy (XPS) spectra. The wettability of films was investigated by water contact angle measurement. The blood compatibility of the grafted films was evaluated by platelet adhesion in platelet rich plasma (PRP) and protein absorption in bovine fibrinogen (BFG). Low platelet adhesion was observed on the grafted films incubated in PRP for 1 and 3 h, respectively. The protein absorption was reduced on the grafted films after incubated in bovine fibrinogen for 2 h. All of these results revealed that the improved blood compatibility was obtained by grafting copolymerization with zwitterionic monomer of sulfobetaine onto polyurethane film. In addition, introducing vinyl groups onto surface through DCC and AA is a novel method to functionalize polyurethane for further modification.

  8. The Theaflavin Monomers Inhibit the Cancer Cells Growth in Vitro

    Institute of Scientific and Technical Information of China (English)

    You-Ying TU; An-Bin TANG; Naoharu WATANABE

    2004-01-01

    The inhibition effects of tea theaflavins complex (TFs), theaflavin-3-3 '-digallate (TFDG),theaflavin-3'-gallate (TF2B), and an unidentified compound (UC) on the growth of human liver cancer BEL-7402 cells, gastric cancer MKN-28 cells and acute promyelocytic leukemia LH-60 cells were investigated.TFs was obtained through the catalysis of catechins with immobilized polyphenols oxidase. TFDG, TF2B and UC were isolated from TFs with high speed countercurrent chromatography (HSCCC). The results showed that TF2B significantly inhibited the growth of all three kinds of cancer cells, TFs, TFDG and UC had some effect on BEL-7402 and MKN-28, but little activity on LH-60. The inhibition effects of TF2B, TFDG, and UC on BEL-7402 and MKN-28 were stronger than TFs. The relationship coefficients between monomer concentration and its inhibition rate against MKN-28 and BEL-7402 were 0.87 and 0.98 for TF2B, 0.96 and 0.98 for UC, respectively. The IC50 values ofTFs, TF2B, and TFDG were 0.18, 0.11, and 0.16 mM on BEL-7402 cells, and 1.11, 0.22, and 0.25 mM on MKN-28 cells respectively.

  9. A comment on water’s structure using monomer fraction data and theories

    DEFF Research Database (Denmark)

    Liang, Xiaodong; Maribo-Mogensen, Bjørn; Tsivintzelis, Ioannis;

    2016-01-01

    Monomer fraction data for water (and other compounds) can provide useful information about their structure and can be used in “advanced” equations of state, which account explicitly for association phenomena. Recent findings about the performance of association theories in representing the monome...

  10. Synthesis and ATRP of novel fluorinated aromatic monomer with pendant sulfonate group

    DEFF Research Database (Denmark)

    Dimitrov, Ivaylo; Jankova Atanasova, Katja; Hvilsted, Søren

    2013-01-01

    Novel, fluorinated monomer with pendant sulfonate group was synthesized utilizing a two-step derivatization of 2,3,4,5,6-pentafluorostyrene (FS). The first step was a nucleophilic substitution of the fluorine atom in para position by hydroxyl group followed by sulfopropylation. The monomer was po...

  11. Monomers, polymers and articles containing the same from sugar derived compounds

    Science.gov (United States)

    Gallagher, James; Reineke, Theresa; Hillmyer, Marc A.

    2016-11-29

    Disclosed herein are monomers formed by reacting a sugar derived compound(s) comprising a lactone and two hydroxyls with a compound(s) comprising an isocyanate and an acrylate or methacrylate. Polymers formed from such monomers, and articles formed from the polymers are also disclosed.

  12. Random sampling for the monomer-dimer model on a lattice

    NARCIS (Netherlands)

    J. van den Berg (Rob); R.M. Brouwer (Rachel)

    1999-01-01

    textabstractIn the monomer-dimer model on a graph, each matching (collection of non-overlapping edges) ${M$ has a probability proportional to $lambda^{|M|$, where $lambda > 0$ is the model parameter, and $|M|$ denotes the number of edges in $M$. An approximate random sample from the monomer-dimer

  13. 46 CFR 151.50-34 - Vinyl chloride (vinyl chloride monomer).

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Vinyl chloride (vinyl chloride monomer). 151.50-34... chloride (vinyl chloride monomer). (a) Copper, aluminum, magnesium, mercury, silver, and their alloys shall... equipment that may come in contact with vinyl chloride liquid or vapor. (b) Valves, flanges, and...

  14. Monomers, polymers and articles containing the same from sugar derived compounds

    Energy Technology Data Exchange (ETDEWEB)

    Gallagher, James; Reineke, Theresa; Hillmyer, Marc A.

    2016-11-29

    Disclosed herein are monomers formed by reacting a sugar derived compound(s) comprising a lactone and two hydroxyls with a compound(s) comprising an isocyanate and an acrylate or methacrylate. Polymers formed from such monomers, and articles formed from the polymers are also disclosed.

  15. A diethyl phosphonate containing oxazoline: Synthesis and characterization of monomer and homopolymer

    Energy Technology Data Exchange (ETDEWEB)

    Hermes, R.E.; Thompson, R.D.; Valdez, L.S.

    1995-05-01

    A diethyl phosphonate oxazoline monomer and its polymer have been synthesized. The monomer appears to polymerize via a ring-opening mechanism giving the expected polyethyleneimine backbone with pendant carbonyl groups. Two distinct molecular weights were produced during polymerization suggesting two mechanisms of chain growth. Studies are underway to elucidate the reasons for this. This polymer has potential as a metal-chelating agent.

  16. A peptidoglycan monomer with the glutamine to serine change and basic peptides bind in silico to TLR-2 (403-455).

    Science.gov (United States)

    Li, Yufeng; Efferson, Clay L; Ramesh, Rajagopal; Peoples, George E; Hwu, Patrick; Ioannides, Constantin G

    2011-04-01

    Bacterial cell wall polysaccharides, such as PGN, bind and activate TLR-2, NOD2 and PGRP on monocytes/macrophages and activate inflammation. We found that the peptides containing basic amino acids (cations) at N -terminus and tyrosine at C-terminus interfered with activating ability of PGN. This finding is significant because the ECD of TLR-2 in vivo encounters a large number of proteins or peptides. Some should bind ECD and "pre-form" TLR-2 to respond or not to its activators, although they cannot activate TLR-2 alone. TLR-2 is receptor for a large number of ligands, including lipopeptides and bacterial cell wall glycoproteins. A binding site for lipopeptides has been identified; however, a binding site for soluble or multimeric PGN has not been proposed. To identify the candidate binding sites of peptides and PGN on TLR-2, we modeled docking of peptides and of the PGN monomer (PGN-S-monomer) to extracellular domain (ECD-TLR-2) of the unbound TLR-2. Quantification, in silico, of free energy of binding (DG) identified 2 close sites for peptides and PGN. The PGN-S-monomer binding site is between amino acids TLR-2, 404-430 or more closely TLR-2, 417-428. The peptide-binding site is between amino acids TLR-2, 434-455. Molecular models show PGN-S-monomer inserts its N -acetyl-glucosamine (NAG) deep in the TLR-2 coil, while its terminal lysine interacts with inside (Glu(403)) and outside pocket (Tyr(378)). Peptides insert their two N -terminal arginines or their C-terminal tyrosines in the TLR-2 coil. PGN did not bind the lipopeptide-binding site in the TLR-2. It can bind the C-terminus, 572-586 (DG = 0.026 kcal), of "lipopeptide-bound" TLR-2. An additional, low-affinity PGN-binding site is TLR-2 (227-237). MTP, MDP, and lysine-less PGN bind to TLR-2, 87-113. This is the first report identifying candidate binding sites of monomer PGN and peptides on TLR-2. Experimental verification of our findings is needed to create synthetic adjuvant for vaccines. Such synthetic PGN

  17. Organic-Inorganic Thermoelectrics from Single Monomers to Polymer Devices

    Science.gov (United States)

    Chang, William Bee

    Waste heat recovery from the human body provides opportunities to power electronics with a source that is cheap and readily available. Thermoelectrics utilize the Seebeck effect to recover useable electrical energy from this waste heat, but are limited due to material parameters being inversely coupled in the bulk. We investigate the role of novel physics at interfaces in order to develop new fundamental understanding of thermoelectrics. The goal is to discover systems where the Seebeck coefficient and the electrical conductivity are not inversely correlated. We investigate thermoelectric transport in organic-organic systems such as scanning tunneling microscope molecular break junctions on the nanoscale, gold nanocrystal arrays on the mesoscale and polymeric ion and mixed conductors at the macroscale. The STM molecular junctions studied in this work can provide design rules to positively couple the Seebeck coefficient and the electrical conductance. Since STM molecular junctions are one-dimensional systems, by minimizing the gap between the molecular orbital energy level and the electrode Fermi energy, the power factor S2? can be optimized. I built a toolbox of chemical structures by first understanding the role of the interface coupling to alkylthiol binding groups of thiophene-based molecules. With this understanding, I designed small molecules based on the monomer unit of donor-acceptor polymers and other conductive polymers. Molecules with very high HOMO levels or low LUMO levels were studied, and the corresponding energy levels were examined using spectroscopic techniques. I then present our work on scaling these molecular junctions to the macroscale using ligand-exchanged gold nanocrystal arrays. Beginning with a model system of alkanethiols and alkanedithiols, I show that the electrical conductivity scales with ligand length exactly as observed in single molecule junctions, and the Seebeck coefficient follows a similar trend. By showing that gold

  18. Nanolayering of phosphoric acid ester monomer on enamel and dentin.

    Science.gov (United States)

    Yoshihara, Kumiko; Yoshida, Yasuhiro; Hayakawa, Satoshi; Nagaoka, Noriyuki; Irie, Masao; Ogawa, Tatsuyuki; Van Landuyt, Kirsten L; Osaka, Akiyoshi; Suzuki, Kazuomi; Minagi, Shogo; Van Meerbeek, Bart

    2011-08-01

    Following the "adhesion-decalcification" concept, specific functional monomers possess the capacity to primary chemically interact with hydroxyapatite (HAp). Such ionic bonding with synthetic HAp has been demonstrated for 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP), manifest as self-assembled "nanolayering". In continuation of that basic research this study aimed to explore whether nanolayering also occurs on enamel and dentin when a 10-MDP primer is applied following a common clinical application protocol. Therefore, the interaction of an experimental 10-MDP primer and a control, commercially available, 10-MDP-based primer (Clearfil SE Bond primer (C-SE), Kuraray) with enamel and dentin was characterized by X-ray diffraction (XRD), complemented with transmission electron microscopy interfacial ultrastructural data upon their reaction with enamel and dentin. In addition, XRD was used to study the effect of the concentration of 10-MDP on nanolayering on dentin. Finally, the stability of the nanolayers was determined by measuring the bond strength to enamel and dentin when a photoinitiator was added to the experimental primer or when interfacial polymerization depended solely on the photoinitiator supplied with the subsequently applied adhesive resin. XRD confirmed nanolayering on enamel and dentin, which was significantly greater on dentin than on enamel, and also when the surface was actively rubbed with the primer. Nanolayering was also proportional to the concentration of 10-MDP in the primer. Finally, the experimental primer needed the photoinitiator to obtain a tensile bond strength to dentin comparable with that of the control C-SE primer (which also contains a photoinitiator), but not when bonded to enamel. It is concluded that self-assembled nanolayering occurs on enamel and dentin, even when following a clinically used application protocol. The lower bonding effectiveness of mild self-etch adhesives to enamel should be ascribed in part to a lower

  19. Vinyl acetate monomer (VAM) genotoxicity profile: relevance for carcinogenicity.

    Science.gov (United States)

    Albertini, Richard J

    2013-09-01

    Vinyl acetate monomer (VAM) is a site-of-contact carcinogen in rodents. It is also DNA reactive and mutagenic, but only after its carboxylesterase mediated conversion to acetaldehyde (AA), a metabolic reaction that also produces acetic acid and protons. As VAM's mutagenic metabolite, AA is normally produced endogenously; detoxification by aldehyde dehydrogenase (ALDH) is required to maintain intra-cellular AA homeostasis. This review examines VAM's overall genotoxicity, which is due to and limited by AA, and the processes leading to mutation induction. VAM and AA have both been universally negative in mutation studies in bacteria but both have tested positive in several in vitro studies in higher organisms that usually employed high concentrations of test agents. Recently however, in vitro studies evaluating submillimolar concentrations of VAM or AA have shown threshold dose-responses for mutagenicity in human cultured cells. Neither VAM nor AA induced systemic mutagenicity in in vivo studies in metabolically competent mice when tested at non-lethal doses while treatments of animals deficient in aldehyde dehydrogenase (Aldh in animals) did induce both gene and chromosome level mutations. The results of several studies have reinforced the critical role for aldehyde dehydrogenase 2 (ALDH2 in humans) in limiting AA's (and therefore VAM's) mutagenicity. The overall aim of this review of VAM's mutagenic potential through its AA metabolite is to propose a mode of action (MOA) for VAM's site-of-contact carcinogenesis that incorporates the overall process of mutation induction that includes both background mutations due to endogenous AA and those resulting from exogenous exposures.

  20. 38 CFR 21.3041 - Periods of eligibility; child.

    Science.gov (United States)

    2010-07-01

    ...; child. 21.3041 Section 21.3041 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS... 38 U.S.C. Chapter 35 Eligibility and Entitlement § 21.3041 Periods of eligibility; child. (a) Eligibility derived from a veteran with a P&T disability. An eligible child's period of eligibility...

  1. 7 CFR 762.105 - Eligibility and substitution of lenders.

    Science.gov (United States)

    2010-01-01

    ... eligibility criteria in this part. The standard eligible lender must demonstrate eligibility and provide such evidence as the Agency may request. (b) Standard eligible lender eligibility criteria. (1) A lender must... enough to the collateral's location so it can properly and efficiently discharge its loan making and...

  2. Influence of the chemical structure of functional monomers on their adhesive performance.

    Science.gov (United States)

    Van Landuyt, K L; Yoshida, Y; Hirata, I; Snauwaert, J; De Munck, J; Okazaki, M; Suzuki, K; Lambrechts, P; Van Meerbeek, B

    2008-08-01

    Functional monomers in adhesive systems can improve bonding by enhancing wetting and demineralization, and by chemical bonding to calcium. This study tested the hypothesis that small changes in the chemical structure of functional monomers may improve their bonding effectiveness. Three experimental phosphonate monomers (HAEPA, EAEPA, and MAEPA), with slightly different chemical structures, and 10-MDP (control) were evaluated. Adhesive performance was determined in terms of microtensile bond strength of 4 cements that differed only for the functional monomer. Based on the Adhesion-Decalcification concept, the chemical bonding potential was assessed by atomic absorption spectrophotometry of the dissolution rate of the calcium salt of the functional monomers. High bond strength of the adhesive cement corresponded to low dissolution rate of the calcium salt of the respective functional monomer. The latter is according to the Adhesion-Decalcification concept, suggestive of a high chemical bonding capacity. We conclude that the adhesive performance of an adhesive material depends on the chemical structure of the functional monomer.

  3. Monomer-dimer model on a scale-free small-world network

    Science.gov (United States)

    Zhang, Zhongzhi; Sheng, Yibin; Jiang, Qiang

    2012-02-01

    The explicit determination of the number of monomer-dimer arrangements on a network is a theoretical challenge, and exact solutions to monomer-dimer problem are available only for few limiting graphs with a single monomer on the boundary, e.g., rectangular lattice and quartic lattice; however, analytical research (even numerical result) for monomer-dimer problem on scale-free small-world networks is still missing despite the fact that a vast variety of real systems display simultaneously scale-free and small-world structures. In this paper, we address the monomer-dimer problem defined on a scale-free small-world network and obtain the exact formula for the number of all possible monomer-dimer arrangements on the network, based on which we also determine the asymptotic growth constant of the number of monomer-dimer arrangements in the network. We show that the obtained asymptotic growth constant is much less than its counterparts corresponding to two-dimensional lattice and Sierpinski fractal having the same average degree as the studied network, which indicates from another aspect that scale-free networks have a fundamentally distinct architecture as opposed to regular lattices and fractals without power-law behavior.

  4. 7 CFR 1499.3 - Eligibility determination.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Eligibility determination. 1499.3 Section 1499.3 Agriculture Regulations of the Department of Agriculture (Continued) COMMODITY CREDIT CORPORATION, DEPARTMENT... determination. (a) An entity will be eligible to become a participant only after FAS determines that the entity...

  5. 24 CFR 964.305 - Eligibility.

    Science.gov (United States)

    2010-04-01

    ... environmental impact regarding eligible activities will be addressed through an environmental review of that..., to be completed by HUD, to ensure that any environmental impact will be addressed before assistance... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Eligibility. 964.305 Section...

  6. 13 CFR 120.346 - Eligibility.

    Science.gov (United States)

    2010-01-01

    ... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Eligibility. 120.346 Section 120.346 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION BUSINESS LOANS Special Purpose Loans International Trade Loans § 120.346 Eligibility. (a) An applicant must establish that: (1) The loan...

  7. 45 CFR 152.14 - Eligibility.

    Science.gov (United States)

    2010-10-01

    ... evidence of the existence or history of certain medical or health condition, as approved or specified by... DEPARTMENT OF HEALTH AND HUMAN SERVICES REQUIREMENTS RELATING TO HEALTH CARE ACCESS PRE-EXISTING CONDITION INSURANCE PLAN PROGRAM Eligibility and Enrollment § 152.14 Eligibility. (a) General rule. An individual is...

  8. 12 CFR 618.8005 - Eligibility.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Eligibility. 618.8005 Section 618.8005 Banks and Banking FARM CREDIT ADMINISTRATION FARM CREDIT SYSTEM GENERAL PROVISIONS Related Services § 618.8005 Eligibility. (a) Farm Credit Banks and associations may offer related services appropriate to...

  9. 48 CFR 932.7004-3 - Eligibility.

    Science.gov (United States)

    2010-10-01

    ... REQUIREMENTS CONTRACT FINANCING DOE Loan Guarantee Authority 932.7004-3 Eligibility. The applicant's eligibility for a guaranteed loan will be based on— (a) Contracting officer determinations and findings... on information contained in the application, the Federal Reserve Bank's report, and information...

  10. 7 CFR 1421.5 - Eligible commodities.

    Science.gov (United States)

    2010-01-01

    ... extraction of oil, wheat, and other commodities designated by CCC, the determination of eligibility will be... oats, mustard seed, rapeseed, safflower seed, flaxseed, and sunflower seed used for a purpose other than to extract oil, the determination of eligibility will be based on quality requirements...

  11. 7 CFR 1781.5 - Eligibility.

    Science.gov (United States)

    2010-01-01

    ... (CONTINUED) RESOURCE CONSERVATION AND DEVELOPMENT (RCD) LOANS AND WATERSHED (WS) LOANS AND ADVANCES § 1781.5 Eligibility. To be eligible for a WS loan, WS advance, or an RCD loan, the sponsoring local organization must... RCD plan as a sponsor of the development to be financed. (b) Be legally organized and established in...

  12. 28 CFR 104.32 - Eligibility review.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Eligibility review. 104.32 Section 104.32 Judicial Administration DEPARTMENT OF JUSTICE (CONTINUED) SEPTEMBER 11TH VICTIM COMPENSATION FUND OF 2001 Claim Intake, Assistance, and Review Procedures § 104.32 Eligibility review. Any claimant...

  13. 24 CFR 291.525 - Eligible teachers.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Eligible teachers. 291.525 Section... Sales Program § 291.525 Eligible teachers. A person qualifies as a teacher for the purposes of the GNND Sales Program if the person is: (a) Employed as a full-time teacher by a state-accredited public...

  14. 46 CFR 13.303 - Eligibility: Experience.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Eligibility: Experience. 13.303 Section 13.303 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY MERCHANT MARINE OFFICERS AND SEAMEN CERTIFICATION OF TANKERMEN Requirements for âTankerman-PIC (Barge)â Endorsement § 13.303 Eligibility: Experience. Each...

  15. 46 CFR 13.503 - Eligibility: Experience.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Eligibility: Experience. 13.503 Section 13.503 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY MERCHANT MARINE OFFICERS AND SEAMEN CERTIFICATION OF TANKERMEN Requirements for âTankerman-Engineerâ Endorsement § 13.503 Eligibility: Experience. (a) Each...

  16. 46 CFR 13.403 - Eligibility: Experience.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Eligibility: Experience. 13.403 Section 13.403 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY MERCHANT MARINE OFFICERS AND SEAMEN CERTIFICATION OF TANKERMEN Requirements for âTankerman-Assistantâ Endorsement § 13.403 Eligibility: Experience. (a) Each...

  17. 46 CFR 13.203 - Eligibility: Experience.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Eligibility: Experience. 13.203 Section 13.203 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY MERCHANT MARINE OFFICERS AND SEAMEN CERTIFICATION OF TANKERMEN Requirements for âTankerman-PICâ Endorsement § 13.203 Eligibility: Experience. Each applicant for...

  18. 12 CFR 615.5140 - Eligible investments.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Eligible investments. 615.5140 Section 615.5140 Banks and Banking FARM CREDIT ADMINISTRATION FARM CREDIT SYSTEM FUNDING AND FISCAL AFFAIRS, LOAN POLICIES AND OPERATIONS, AND FUNDING OPERATIONS Investment Management § 615.5140 Eligible investments....

  19. 28 CFR 90.13 - Eligibility.

    Science.gov (United States)

    2010-07-01

    ... Administration DEPARTMENT OF JUSTICE (CONTINUED) VIOLENCE AGAINST WOMEN The STOP (Services ⢠Training ⢠Officers ⢠Prosecutors) Violence Against Women Formula Grant Program § 90.13 Eligibility. (a) All States are eligible to apply for, and to receive, grants to combat violent crimes against women under...

  20. 24 CFR 320.23 - Eligible issuers.

    Science.gov (United States)

    2010-04-01

    ...) GOVERNMENT NATIONAL MORTGAGE ASSOCIATION, DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT GUARANTY OF MORTGAGE-BACKED SECURITIES Bond-Type Securities § 320.23 Eligible issuers. Any corporation, trust, partnership, or... the capability to assemble acceptable and eligible mortgages in sufficient quantity to support...

  1. 12 CFR 1261.4 - Director eligibility.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 7 2010-01-01 2010-01-01 false Director eligibility. 1261.4 Section 1261.4 Banks and Banking FEDERAL HOUSING FINANCE AGENCY FEDERAL HOME LOAN BANKS FEDERAL HOME LOAN BANK DIRECTORS Federal Home Loan Bank Boards of Directors: Eligibility and Elections § 1261.4...

  2. 24 CFR 570.703 - Eligible activities.

    Science.gov (United States)

    2010-04-01

    ... construction, reconstruction, installation of public and other site improvements, utilities or facilities... sector financing of debt obligations under this subpart. (h) Housing rehabilitation eligible under § 570... (2) Community economic development projects eligible under § 570.204. (j) Construction of housing...

  3. 25 CFR 273.12 - Eligible students.

    Science.gov (United States)

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Eligible students. 273.12 Section 273.12 Indians BUREAU... PROGRAM EDUCATION CONTRACTS UNDER JOHNSON-O'MALLEY ACT Application Process § 273.12 Eligible students. Indian students, from age 3 years through grade(s) 12, except those who are enrolled in Bureau...

  4. 29 CFR 825.110 - Eligible employee.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Eligible employee. 825.110 Section 825.110 Labor... employee. (a) An “eligible employee” is an employee of a covered employer who: (1) Has been employed by the... worksite where 50 or more employees are employed by the employer within 75 miles of that worksite....

  5. 10 CFR 600.6 - Eligibility.

    Science.gov (United States)

    2010-01-01

    ... Federal agency, and for which competition for support would have a significant adverse effect on... maximum amount of competition feasible. (b) Restricted eligibility. If DOE restricts eligibility, an... Contracting Officer; and (iii) Approved by an official no less than one level below the responsible...

  6. 7 CFR 4279.29 - Eligible lenders.

    Science.gov (United States)

    2010-01-01

    ...; audited financial statements not more than 1 year old; sources of funds for the proposed loans; office... 7 Agriculture 15 2010-01-01 2010-01-01 false Eligible lenders. 4279.29 Section 4279.29 Agriculture... UTILITIES SERVICE, DEPARTMENT OF AGRICULTURE GUARANTEED LOANMAKING General § 4279.29 Eligible lenders....

  7. Molecular weight recognition in the multiple-stranded helix of a synthetic polymer without specific monomer-monomer interaction.

    Science.gov (United States)

    Kumaki, Jiro; Kawauchi, Takehiro; Ute, Koichi; Kitayama, Tatsuki; Yashima, Eiji

    2008-05-21

    Stereoregular isotactic and syndiotactic poly(methyl methacrylate)s (it- and st-PMMAs) are known to form a multiple-stranded complementary helix, so-called stereocomplex (SC) through van der Waals interactions, which is a rare example of helical supramolecular structures formed by a commodity polymer. In this study, we prepared SCs by using uniform it- and st-PMMAs and those with a narrow molecular weight distribution having different molecular weights and investigated their structures in detail using high-resolution atomic force microscopy as a function of the molecular weight and molecular weight distribution of the component PMMAs. We found that complementary it- and st-PMMAs with the longer molecular length determine the total length of the SC, and molecules of the shorter component associate until they fill up or cover the longer component. These observations support a supramolecular triple-stranded helical structure of the SCs composed of a double-stranded helix of two intertwined it-PMMA chains included in a single helix of st-PMMA, and this triple-stranded helix model of the SCs appears to be applicable to the it- and st-PMMAs having a wide range of molecular weights we employed in this study. In homogeneous double-stranded helices of it-PMMA, it has been found that, in mixtures of two it-PMMAs with different molecular weights, chains of the same molecular weight selectively form a double-stranded it-PMMA helix, or recognize the molecular weights of each other ("molecular sorting"). We thus demonstrate that molecular weight recognition is possible, without any specific interaction between monomer units, through the formation of a topological multiple-stranded helical structure based upon van der Waals interaction.

  8. Investigation of hydrogen atom addition to vinyl monomers by time resolved ESR spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Beckert, D.; Mehler, K.

    1983-07-01

    By means of time resolved ESR spectroscopy in the microsecond time scale the H atom addition to different vinyl monomers was investigated. The H atoms produced by pulse radiolysis of aqueous solutions show a strong recombination CIDEP effect which also allows the recombination rate constant of H atoms to be determined. By analysis of ESR time profiles with the modified Bloch equations the relaxation times T/sub 1/, T/sub 2/, the polarization factors and the chemical rate constants with scavengers were obtained. Besides the H atom addition rate constants to different vinyl monomers the structure of the monomer radical was determined for acrylic acid.

  9. Influence of Monomer Types on the Designability of a Protein-Model Chain

    Institute of Scientific and Technical Information of China (English)

    梁好均; 王元元

    2002-01-01

    In a three-dimensional off-lattice model, the method of Shakhnovich and Gutin for minimizing the Hamiltonian is applied to the design of a protein-model chain. The effect of the number of hydrophobic and hydrophilic monomer types on the designability ora protein-model chain is investigated. The simulation results reveal that the number of hydrophobic monomer types is a much more important factor than that of the polar monomer types in the design of a protein-model chain.

  10. A review of adaptive mechanisms in cell responses towards oxidative stress caused by dental resin monomers.

    Science.gov (United States)

    Krifka, Stephanie; Spagnuolo, Gianrico; Schmalz, Gottfried; Schweikl, Helmut

    2013-06-01

    Dental composite resins are biomaterials commonly used to aesthetically restore the structure and function of teeth impaired by caries, erosion, or fracture. Residual monomers released from resin restorations as a result of incomplete polymerization processes interact with living oral tissues. Monomers like triethylene glycol dimethacrylate (TEGDMA) or 2-hydroxylethyl methacrylate (HEMA) are cytotoxic via apoptosis, induce genotoxic effects, and delay the cell cycle. Monomers also influence the response of cells of the innate immune system, inhibit specific odontoblast cell functions, or delay the odontogenic differentiation and mineralization processes in pulp-derived cells including stem cells. These observations indicate that resin monomers act as environmental stressors which inevitably disturb regulatory cellular networks through interference with signal transduction pathways. We hypothesize that an understanding of the cellular mechanisms underlying these phenomena will provide a better estimation of the consequences associated with dental therapy using composite materials, and lead to innovative therapeutic strategies and improved materials being used at tissue interfaces within the oral cavity. Current findings strongly suggest that monomers enhance the formation of reactive oxygen species (ROS), which is most likely the cause of biological reactions activated by dental composites and resin monomers. The aim of the present review manuscript is to discuss adaptive cell responses to oxidative stress caused by monomers. The particular significance of a tightly controlled network of non-enzymatic as well as enzymatic antioxidants for the regulation of cellular redox homeostasis and antioxidant defense in monomer-exposed cells will be addressed. The expression of ROS-metabolizing antioxidant enzymes like superoxide dismutase (SOD1), glutathione peroxidase (GPx1/2), and catalase in cells exposed to monomers will be discussed with particular emphasis on the role

  11. Dynamic conformations of nucleophosmin (NPM1 at a key monomer-monomer interface affect oligomer stability and interactions with granzyme B.

    Directory of Open Access Journals (Sweden)

    Wei D Duan-Porter

    Full Text Available Nucleophosmin (NPM1 is an abundant, nucleolar tumor antigen with important roles in cell proliferation and putative contributions to oncogenesis. Wild-type NPM1 forms pentameric oligomers through interactions at the amino-terminal core domain. A truncated form of NPM1 found in some hepatocellular carcinoma tissue formed an unusually stable oligomer and showed increased susceptibility to cleavage by granzyme B. Initiation of translation at the seventh methionine generated a protein (M7-NPM that shared all these properties. We used deuterium exchange mass spectrometry (DXMS to perform a detailed structural analysis of wild-type NPM1 and M7-NPM, and found dynamic conformational shifts or local "unfolding" at a specific monomer-monomer interface which included the β-hairpin "latch." We tested the importance of interactions at the β-hairpin "latch" by replacing a conserved tyrosine in the middle of the β-hairpin loop with glutamic acid, generating Y67E-NPM. Y67E-NPM did not form stable oligomers and further, prevented wild-type NPM1 oligomerization in a dominant-negative fashion, supporting the critical role of the β-hairpin "latch" in monomer-monomer interactions. Also, we show preferential cleavage by granzyme B at one of two available aspartates (either D161 or D122 in M7-NPM and Y67E-NPM, whereas wild-type NPM1 was cleaved at both sites. Thus, we observed a correlation between the propensity to form oligomers and granzyme B cleavage site selection in nucleophosmin proteins, suggesting that a small change at an important monomer-monomer interface can affect conformational shifts and impact protein-protein interactions.

  12. 76 FR 55419 - Report on Countries That Are Candidates for Millennium Challenge Account Eligibility in Fiscal...

    Science.gov (United States)

    2011-09-07

    ... FY12. Prohibited Countries: Low Income Category Burma is subject to numerous restrictions, including... Programs Appropriations Act (Pub. L. 104-208), which prohibits assistance to the government of Burma until... assistance to the government of a country whose duly elected head of government is deposed by military...

  13. 77 FR 21111 - Report on Countries That Are Candidates for Millennium Challenge Account Eligibility in Fiscal...

    Science.gov (United States)

    2012-04-09

    ... programs that advance the progress of such countries to achieve lasting economic growth and poverty... its people; and (b) considering the opportunity to reduce poverty and generate economic growth in the... it: Meets one of the following tests: Has a per capita income that is not greater than the World...

  14. 75 FR 52990 - Report on Countries That Are Candidates for Millennium Challenge Account Eligibility in Fiscal...

    Science.gov (United States)

    2010-08-30

    ... countries to achieve lasting economic growth and poverty reduction. The Act requires the Millennium... to reduce poverty and generate economic growth in the country. These steps include the submission of... country in the then most recent edition of the World Development Report for Reconstruction and...

  15. 76 FR 69290 - Report on Countries That Are Candidates for Millennium Challenge Account Eligibility in Fiscal...

    Science.gov (United States)

    2011-11-08

    ... programs that advance the progress of such countries to achieve lasting economic growth and poverty... its people; and (b) considering the opportunity to reduce poverty and generate economic growth in the... classified as a lower middle income country in the then most recent edition of the World Development...

  16. 77 FR 19360 - Report on Countries That Are Candidates for Millennium Challenge Account Eligibility in Fiscal...

    Science.gov (United States)

    2012-03-30

    ... programs that advance the progress of such countries to achieve lasting economic growth and poverty... its people; and (b) considering the opportunity to reduce poverty and generate economic growth in the... it: Meets one of the following tests: Has a per capita income that is not greater than the World...

  17. 78 FR 52984 - Report on Countries That Are Candidates for Millennium Challenge Account Eligibility in Fiscal...

    Science.gov (United States)

    2013-08-27

    ... achieve lasting economic growth and poverty reduction. The Act requires the Millennium Challenge... poverty and generate economic growth in the country. These steps include the submission of reports to the... identified by the World Bank and provided that a country that changes during the fiscal year from low...

  18. 77 FR 53917 - Report on Countries That Are Candidates for Millennium Challenge Account Eligibility in Fiscal...

    Science.gov (United States)

    2012-09-04

    ... countries to achieve lasting economic growth and poverty reduction. The Act requires the Millennium... to reduce poverty and generate economic growth in the country. These steps include the submission of... poorest countries as identified by the World Bank and provided that a country that changes in the...

  19. Preserving the Sequence of a Biopolymer's Monomers as They Enter an Electrospray Mass Spectrometer

    Science.gov (United States)

    Maulbetsch, William; Wiener, Benjamin; Poole, William; Bush, Joseph; Stein, Derek

    2016-11-01

    This paper investigates how faithfully an electrospray mass spectrometer reports the order of monomers of a single biopolymer in the context of two sequencing strategies. We develop a simplified one-dimensional theoretical model of the dynamics of Brownian particles in the Taylor cone of an electropray source, where free monomers drift towards the apex in an elongational force gradient. The likelihood that neighboring particles will invert their order decreases near the apex because the strength of the force gradient increases. Neighboring monomers on a stretched biopolymer should be cleaved by photofragmentation within about 3 nm of the apex if they are to enter the mass spectrometer in sequence with 95% probability under typical experimental conditions. Alternatively, if the monomers are cleaved processively at milliseconds-long intervals by an enzyme, their sequence will be faithfully reported with 95% confidence if the enzyme is within about 117 nm of the apex.

  20. Critical behavior in the cubic dimer model at nonzero monomer density

    Science.gov (United States)

    Sreejith, G. J.; Powell, Stephen

    2014-01-01

    We study critical behavior in the classical cubic dimer model (CDM) in the presence of a finite density of monomers. With attractive interactions between parallel dimers, the monomer-free CDM exhibits an unconventional transition from a Coulomb phase to a dimer crystal. Monomers act as charges (or monopoles) in the Coulomb phase and, at nonzero density, lead to a standard Landau-type transition. We use large-scale Monte Carlo simulations to study the system in the neighborhood of the critical point, and find results in agreement with detailed predictions of scaling theory. Going beyond previous studies of the transition in the absence of monomers, we explicitly confirm the distinction between conventional and unconventional criticality, and quantitatively demonstrate the crossover between the two. Our results also provide additional evidence for the theoretical claim that the transition in the CDM belongs in the same universality class as the deconfined quantum critical point in the SU (2) JQ model.

  1. Radiation-induced graft copolymerization of binary monomer mixture containing acrylonitrile onto polyethylene films

    Science.gov (United States)

    Choi, Seong-Ho; Nho, Young Chang

    2000-04-01

    Graft copolymerization of acrylonitrile (AN)/acrylic acid (AA), acrylonitrile (AN)/methacrylic acid (MA), and acrylonitrile (AN)/glycidyl methacrylate (GMA) onto pre-irradiated polyethylene (PE) films were studied. The effect of reaction conditions such as solvents, additives, and monomer composition on the grafting yields was investigated. The extent of grafting was found to increase with increasing sulfuric acid concentration when sulfuric acid as an additive was added to the grafting solution. In AN/AA mixture, the proportion of acrylonitrile in the copolymer increased with an increasing AN component in feed monomers. On the other hand, in AN/MA mixture, acrylonitrile component in copolymer was very slight in spite of the increase AN component in feed monomers. In the AN/GMA mixture, the proportion of acrylonitrile in the copolymer increased with increasing acrylonitrile component in AN/GMA feed monomer.

  2. Computational studies of the structural properties of the monomer and dimer of Aβ(1-28)

    Science.gov (United States)

    Dong, Xiao; Chen, Wei; Mousseau, Normand; Derreumaux, Philippe

    2007-03-01

    Neurodegenerative diseases are linked with the self-assembly of normally soluble proteins into amyloid fibrils. In this work, in silico characterization of the structures of the monomer and dimer of Aβ(1-28) are studied with the coarse-grained OPEP model using the activation-relaxation technique (ART nouveau). We find a dominant anti-parallel β-sheet structure present for both the monomer and dimer. While the monomer does not adopt a stable conformation, it fluctuates around a well-defined structure: starting from the end point, the monomer wraps a first time around, producing a β-hairpin and returns on the other side of the N-terminal, forming a three-strand β-sheet. The dimer assembles in a similar fashion, but with the two strands interlocking. The thermodynamics of the molecular assemblies and various folding path-ways are further studied using molecular dynamics.

  3. A novel quinoxaline bearing electroactive monomer: Pyrrole as the donor moiety

    Energy Technology Data Exchange (ETDEWEB)

    Taskin, Asli Tuba; Balan, Abidin; Epik, Bugra; Yildiz, Ersin [Middle East Technical University, Department of Chemistry, 06531, Ankara (Turkey); Udum, Yasemin Arslan [Gazi University, Institute of Science and Technology, Department of Advanced Technologies, 06570, Ankara (Turkey); Toppare, Levent [Middle East Technical University, Department of Chemistry, 06531, Ankara (Turkey)], E-mail: toppare@metu.edu.tr

    2009-09-30

    A novel electroactive monomer 5,8-di(1H-pyrrol-2-yl)-2,3-di(thiophen-2-yl)quinoxaline (PTQ) was successfully synthesized and its electrochromic properties were reported. Nuclear magnetic resonance ({sup 1}H NMR-{sup 13}C NMR) and mass spectroscopy were used to characterize the monomer. The monomer was electrochemically polymerized in the presence of tetrabutylammonium perchlorate (TBAP) as supporting electrolyte in dichloromethane. Monomer reveals relatively low oxidation potential at +0.70 V. Spectroelectrochemical behaviors and switching ability of homopolymer were investigated by UV-vis spectroscopy and cyclic voltammetry. Two {pi}-{pi}* transitions were observed at 400 and 815 nm with a low band gap, 1.0 eV. Polymer possesses 66% optical contrast in the Near IR region, which may be promising in NIR electrochromic device applications.

  4. Facile synthesis of allyl resinate monomer in an aqueous solution under microwave irradiation

    Indian Academy of Sciences (India)

    Yanju Lu; Mixia Wang; Zhendong Zhao; Yuxiang Chen; Shichao Xu; Jing Wang; Liangwu Bi

    2015-07-01

    We have developed a facile method for production of allyl resinate monomer (allyl rosin ester) via a phase transfer reaction under microwave irradiation. The synthesis of allyl resinate was conducted using allyl chloride and sodium resinate as starting materials in aqueous solution at 50°C for 30 min with a yield of 94.7%, which is 20% higher than conventional heating method. The products precipitated spontaneously from the aqueous phase after reaction, which significantly facilitated the subsequent separation of monomer products. The synthesized monomer product appeared as a viscous liquid, with a viscosity of 460 mPa·s at 25°C and a density of 1.0469 g/cm3. The physical and chemical properties suggested that the synthesized monomer has great potential for free radical polymerization.

  5. Thermodynamically stable amyloid-β monomers have much lower membrane affinity than the small oligomers.

    Science.gov (United States)

    Sarkar, Bidyut; Das, Anand K; Maiti, Sudipta

    2013-01-01

    Amyloid beta (Aβ) is an extracellular 39-43 residue long peptide present in the mammalian cerebrospinal fluid, whose aggregation is associated with Alzheimer's disease (AD). Small oligomers of Aβ are currently thought to be the key to toxicity. However, it is not clear why the monomers of Aβ are non-toxic, and at what stage of aggregation toxicity emerges. Interactions of Aβ with cell membranes is thought to be the initiator of toxicity, but membrane binding studies with different preparations of monomers and oligomers have not settled this issue. We have earlier found that thermodynamically stable Aβ monomers emerge spontaneously from oligomeric mixtures upon long term incubation in physiological solutions (Nag et al., 2011). Here we show that the membrane-affinity of these stable Aβ monomers is much lower than that of a mixture of monomers and small oligomers (containing dimers to decamers), providing a clue to the emergence of toxicity. Fluorescently labeled Aβ40 monomers show negligible binding to cell membranes of a neuronal cell line (RN46A) at physiological concentrations (250 nM), while oligomers at the same concentrations show strong binding within 30 min of incubation. The increased affinity most likely does not require any specific neuronal receptor, since this difference in membrane-affinity was also observed in a somatic cell-line (HEK 293T). Similar results are also obtained for Aβ42 monomers and oligomers. Minimal amount of cell death is observed at these concentrations even after 36 h of incubation. It is likely that membrane binding precedes subsequent slower toxic events induced by Aβ. Our results (a) provide an explanation for the non-toxic nature of Aβ monomers, (b) suggest that Aβ toxicity emerges at the initial oligomeric phase, and (c) provide a quick assay for monitoring the benign-to-toxic transformation of Aβ.

  6. Effect of food simulating liquids on release of monomers from two dental resin composites

    Directory of Open Access Journals (Sweden)

    Ghavam M

    2010-06-01

    Full Text Available "nBackground and Aims: The elution of residual monomers from cured dental composites to oral cavity has a harmful effect on human health and can affect their clinical durability. The purpose of this study was to evaluate the amount of eluted monomers (Bis-GMA, TEGDMA, UDMA from two types of composites (Gradia and P60 after exposure to food simulating liquids such as ethanol (25, 50, 75 % and heptane 50 % for 24 hours and 7 days. "nMaterials and Methods: Forty specimens of each composite were prepared. Equal numbers of each composite were immersed in tubes containing 2cc volumes of 25, 50, 75 % ethanole and 50 % heptane. The amount of eluted monomers in standard condition such as Bis-GMA, TEGDMA and UDMA was measured by GC/MS (Gas Chromatography/Mass Spectroscopy and results were statistically analysed by three way and one way ANOVA. P<0.05 was considered as the level of significancy. "nResults: The results showed that Gradia released more TEGDMA than P60. In assessing the effect of environment, the result showed that ethanol caused releasing monomers more than heptane and the concentration rate of 75 % ethanole resulted in most releasing of monomers. In assessing the effect of time, the observation showed that more monomers were released 7 days compared to 24 hours. Bis-GMA and UDMA were not detected in any solutions in these conditions. "nConclusion: Ethanole caused more release of monomers than heptane and 75 % ethanole released the most amount of monomers. Gradia released more amount of TEGDMA than P60.

  7. Triptycene-based ladder monomers and polymers, methods of making each, and methods of use

    KAUST Repository

    Pinnau, Ingo

    2015-02-05

    Embodiments of the present disclosure provide for a triptycene-based A-B monomer, a method of making a triptycene-based A-B monomer, a triptycene-based ladder polymer, a method of making a triptycene-based ladder polymers, a method of using triptycene-based ladder polymers, a structure incorporating triptycene-based ladder polymers, a method of gas separation, and the like.

  8. Qualitative and quantitative analysis of monomers in polyesters for food contact materials.

    Science.gov (United States)

    Brenz, Fabrian; Linke, Susanne; Simat, Thomas

    2017-02-01

    Polyesters (PESs) are gaining more importance on the food contact material (FCM) market and the variety of properties and applications is expected to be wide. In order to acquire the desired properties manufacturers can combine several FCM-approved polyvalent carboxylic acids (PCAs) and polyols as monomers. However, information about the qualitative and quantitative composition of FCM articles is often limited. The method presented here describes the analysis of PESs with the identification and quantification of 25 PES monomers (10 PCA, 15 polyols) by HPLC with diode array detection (HPLC-DAD) and GC-MS after alkaline hydrolysis. Accurate identification and quantification were demonstrated by the analysis of seven different FCM articles made of PESs. The results explained between 97.2% and 103.4% w/w of the polymer composition whilst showing equal molar amounts of PCA and polyols. Quantification proved to be precise and sensitive with coefficients of variation (CVs) below 6.0% for PES samples with monomer concentrations typically ranging from 0.02% to 75% w/w. The analysis of 15 PES samples for the FCM market revealed the presence of five different PCAs and 11 different polyols (main monomers, co-monomers, non-intentionally added substances (NIAS)) showing the wide variety of monomers in modern PESs. The presented method provides a useful tool for commercial, state and research laboratories as well as for producers and distributors facing the task of FCM risk assessment. It can be applied for the identification and quantification of migrating monomers and the prediction of oligomer compositions from the identified monomers, respectively.

  9. Shrinkage strain – Rates study of dental composites based on (BisGMA/TEGDMA monomers

    Directory of Open Access Journals (Sweden)

    A. Amirouche-Korichi

    2017-02-01

    The results revealed that the fraction of opaque filler had no significant effect on the shrinkage strain-rate and on the time at maximum shrinkage strain-rate but these two parameters are closely related to the monomer ratios and viscosity of the organic matrix. The results have confirmed the proportionality of the shrinkage strain and DC and showed that the filler contents and monomer ratios would not affect this proportionality.

  10. Radiation Induced Crosslinking of Polyethylene in the Presence of Bifunctional Vinyl Monomers

    DEFF Research Database (Denmark)

    Joshi, M. S.; Singer, Klaus Albert Julius; Silverman, J.

    1977-01-01

    Several reports have been published showing that the radiation induced grafting of bifunctional vinyl monomers to low density polyethylene results in a product with an unusually high density of crosslinks. The same grafting reactions are shown to reduce the incipient gel dose by more than a factor...... of fifty. This paper is concerned with the apparent crosslinking produced by the radiation grafting of two monomers to polyethylene: acrylic acid and acrylonitrile....

  11. Concomitant sensitization to glutaraldehyde and methacrylic monomers among dentists and their patients

    OpenAIRE

    Maya Grigorievna Lyapina; Maria Dencheva; Assya Krasteva-Panova; Mariana Tzekova-Yaneva; Mariela Deliverska; Angelina Kisselova-Yaneva

    2016-01-01

    Background: A multitude of methacrylic monomers is used in dentistry. Glutaraldehyde (G) is used in dental practice and consumer products as a broad-spectrum antimicrobial agent. The purpose of our study is to evaluate the frequency and the risk of concomitant sensitization to some methacrylic monomers (methyl methacrylate (MMA), triethyleneglycol dimethacrylate (TEGDMA), ethyleneglycol dimethacrylate (EGDMA), 2,2-bis-[4-(2-hydroxy-3-methacrylo-xypropoxy)phenyl]-propane (Bis-GMA), 2-hydroxy-e...

  12. Residual monomer content determination in some acrylic denture base materials and possibilities of its reduction

    Directory of Open Access Journals (Sweden)

    Kostić Milena

    2009-01-01

    Full Text Available Background/Aim. Polymethyl methacrylate is used for producing a denture basis. It is a material made by the polymerization process of methyl methacrylate. Despite of the polymerization type, there is a certain amount of free methyl methacrylate (residual monomer incorporated in the denture, which can cause irritation of the oral mucosa. The aim of this study was to determine the amount of residual monomer in four different denture base acrylic resins by liquid chromatography and the possibility of its reduction. Methods. After the polymerization, a postpolymerization treatment was performed in three different ways: in boiling water for thirty minutes, with 500 W microwaves for three minutes and in steam bath at 22º C for one to thirty days. Results. The obtained results showed that the amount of residual monomer is significantly higher in cold polymerizing acrylates (9.1-11%. The amount of residual monomer after hot polymerization was in the tolerance range (0.59- 0.86%. Conclusion. The obtained results denote a low content of residual monomer in the samples which have undergone postpolymerization treatment. A lower percent of residual monomer is established in samples undergone a hot polymerization.

  13. Impregnation of mortars with monomers and their radiolytic polymerization. [Gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Gadalla, A.M.; El-Derini, M.E.

    1984-10-01

    Mortars were cured for a sufficient period to give sufficient strength and were then dried to remove the free water without dehydrating the compounds formed. Dried specimens were evacuated and impregnated with a mixture of styrene and acrylonitrile monomers which gives high mechanical properties after polymerization. Positive pressure was then applied, and polymerization was done radiolytically. The effect of degree and period of evacuation, the positive pressure and the irradiation dose on monomer loading, tensile and compressive strength were studied, and the optimum operating conditions were established. The achieved strength was correlated with the fraction of open pores impregnated. The composites investigated have the same volume fraction of mortar, and the polymer is added at the expense of the open porosity causing nearly an exponential increase in strength. Only 80% of the open pores were filled with polymers due to the difference in density between the polymer and the monomer, loss of monomer, and the presence of entrapped gas consisting of residual air and residual water vapor and monomer vapor, as well as due to the inability to fill all the micropores with monomer. A compressive strengh four times that of plain mortar and a tensile strength eight times that of plain mortar were achieved. 18 references, 12 figures.

  14. Tandem ring-opening/ring-closing metathesis polymerization: relationship between monomer structure and reactivity.

    Science.gov (United States)

    Park, Hyeon; Lee, Ho-Keun; Choi, Tae-Lim

    2013-07-24

    Monomers containing either cycloalkenes with low ring strain or 1-alkynes are poor monomers for olefin metathesis polymerization. Ironically, keeping two inactive functional groups in proximity within one molecule can make it an excellent monomer for metathesis polymerization. Recently, we demonstrated that monomer 1 having cyclohexene and propargyl moieties underwent rapid tandem ring-opening/ring-closing metathesis (RO/RCM) polymerization via relay-type mechanism. Furthermore, living polymerization was achieved when a third-generation Grubbs catalyst was used. Here, we present a full account on this tandem polymerization by investigating how various structural modifications of the monomers affected the reactivity of the tandem polymerization. We observed that changing the ring size of the cycloalkene moieties, the length of the alkynes, and linker units influenced not only the polymerization rates but also the reactivities of Diels-Alder reaction, which is a post-modification reaction of the resulting polymers. Also, the mechanism of tandem polymerization was studied by conducting end-group analysis using (1)H NMR analysis, thereby concluding that the polymerization occurred by the alkyne-first pathway. With this mechanistic conclusion, factors responsible for the dramatic structure-reactivity relationship were proposed. Lastly, tandem RO/RCM polymerization of monomers containing sterically challenging trisubstituted cycloalkenes was successfully carried out to give polymer repeat units having tetrasubstituted cycloalkenes.

  15. Enzymatic Specific Production and Chemical Functionalization of Phenylpropanone Platform Monomers from Lignin.

    Science.gov (United States)

    Ohta, Yukari; Hasegawa, Ryoichi; Kurosawa, Kanako; Maeda, Allyn H; Koizumi, Toshio; Nishimura, Hiroshi; Okada, Hitomi; Qu, Chen; Saito, Kaori; Watanabe, Takashi; Hatada, Yuji

    2017-01-20

    Enzymatic catalysis is an ecofriendly strategy for the production of high-value low-molecular-weight aromatic compounds from lignin. Although well-definable aromatic monomers have been obtained from synthetic lignin-model dimers, enzymatic-selective synthesis of platform monomers from natural lignin has not been accomplished. In this study, we successfully achieved highly specific synthesis of aromatic monomers with a phenylpropane structure directly from natural lignin using a cascade reaction of β-O-4-cleaving bacterial enzymes in one pot. Guaiacylhydroxylpropanone (GHP) and the GHP/syringylhydroxylpropanone (SHP) mixture are exclusive monomers from lignin isolated from softwood (Cryptomeria japonica) and hardwood (Eucalyptus globulus). The intermediate products in the enzymatic reactions show the capacity to accommodate highly heterologous substrates at the substrate-binding sites of the enzymes. To demonstrate the applicability of GHP as a platform chemical for bio-based industries, we chemically generate value-added GHP derivatives for bio-based polymers. Together with these chemical conversions for the valorization of lignin-derived phenylpropanone monomers, the specific and enzymatic production of the monomers directly from natural lignin is expected to provide a new stream in "white biotechnology" for sustainable biorefineries.

  16. 23 CFR 656.5 - Eligibility.

    Science.gov (United States)

    2010-04-01

    ... on but must serve a Federal-aid system to be eligible for Federal-aid primary, secondary, or urban system funds depending on the system served. The Federal share payable will be in accordance with the...

  17. Dual Eligibles and Potentially Avoidable Hospitalizations

    Data.gov (United States)

    U.S. Department of Health & Human Services — About 25 percent of the hospitalizations for dual eligible beneficiaries in 2005 were potentially avoidable. Medicare and Medicaid spending for those potentially...

  18. Presumptive Eligibility for Medicaid and CHIP Coverage

    Data.gov (United States)

    U.S. Department of Health & Human Services — Health care providers and Head Start programs can play a major role in finding and enrolling uninsured children through presumptive eligibility. States can authorize...

  19. 42 CFR 67.13 - Eligible projects.

    Science.gov (United States)

    2010-10-01

    ... Research, Evaluation, Demonstration, and Dissemination Projects § 67.13 Eligible projects. Projects for research, evaluations, demonstrations, dissemination of information (including research on dissemination... approaches to such assessments, and technology diffusion; (e) Health care costs and financing,...

  20. 42 CFR 455.230 - Eligibility requirements.

    Science.gov (United States)

    2010-10-01

    ... Eligibility requirements. CMS may enter into a contract with an entity to perform the activities described at... in relation to Title XIX of the Social Security Act and in other cases arising out of such...

  1. Patent Eligibility of Business Methods in Canada

    Institute of Scientific and Technical Information of China (English)

    Zheng Li; Brian Lee

    2011-01-01

    @@ While the same fundamental principles underlining patent law are generally accepted in every major jurisdiction in the world, the patent eligibility of computer-implemented business method inventions ("business methods") has received different treatment between jurisdictions.

  2. 7 CFR 1470.6 - Eligibility requirements.

    Science.gov (United States)

    2010-01-01

    ...) Be in compliance with the highly erodible land and wetland conservation provisions found at 7 CFR... OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS CONSERVATION STEWARDSHIP PROGRAM General... limited to, information related to eligibility requirements and ranking factors; conservation activity...

  3. 7 CFR 1980.419 - Eligible lenders.

    Science.gov (United States)

    2010-01-01

    ...) PROGRAM REGULATIONS (CONTINUED) GENERAL Business and Industrial Loan Program § 1980.419 Eligible lenders... Director will submit to the Finance Office Form FmHA or its successor agency under Public Law 103-354 1980...

  4. Dual Eligibles and Potentially Avoidable Hospitalizations

    Data.gov (United States)

    U.S. Department of Health & Human Services — About 25 percent of the hospitalizations for dual eligible beneficiaries in 2005 were potentially avoidable. Medicare and Medicaid spending for those potentially...

  5. 32 CFR 1656.5 - Eligible employment.

    Science.gov (United States)

    2010-07-01

    ... or public building maintenance, correctional facility support programs, juvenile rehabilitation... National Defense Other Regulations Relating to National Defense SELECTIVE SERVICE SYSTEM ALTERNATIVE SERVICE § 1656.5 Eligible employment. (a) The Director will determine in accordance with the...

  6. 25 CFR 1001.2 - Applicant eligibility.

    Science.gov (United States)

    2010-04-01

    ... § 1001.2 Applicant eligibility. Any tribe or consortium of tribes seeking inclusion in the applicant pool... governing body. (c) Demonstrate financial stability and financial management capability by...

  7. Kinetic measurement of esterase-mediated hydrolysis for methacrylate monomers used in dental composite biomaterials

    Science.gov (United States)

    Russo, Karen Ann

    Methacrylate-based monomers are routinely used in medical biomaterials. Monomers undergo polymerization reactions to form the solid resin. These polymerization reactions can be incomplete thus making unpolymerized monomer available for possible biodistribution. Understanding the fate of these monomers is essential not only for their toxicological profile but also for development of future biomaterials. Aromatic methacrylate-based monomers included in this study were bisphenol A dimethacrylate and bisphenol A diglycidyl dimethathacrylate; aliphatic methacrylate monomers were 2-hydroxyethyl methacrylate and triethyleneglycol dimethacrylate. These compounds contain ester moieties thought to be susceptible to esterase-mediated hydrolysis. The hypothesis was that the ester bond of the methacrylate monomers can be hydrolyzed by esterases and these reactions would occur in a measurable, time-dependent manner confirmed by specific Michaelis-Menten kinetic relationships. Including aliphatic and aromatic methacrylate monomers in this work allowed for structure-based comparisons. In vitro enzymolysis of the test compounds by acetylcholinesterase and cholesterol esterase was performed in buffered solutions. The hydrolysis reactions were monitored by high performance liquid chromatography with ultraviolet detection. The disappearance of parent compound and appearance of hydrolysis products were quantitated. The aromatic methacrylate monomers, bisphenol A dimethacrylate and bisphenol A diglycidyl dimethacrylate, were resistant to acetylcholine esterase hydrolysis but were converted by cholesterol esterase. The putative xenoestrogen, bisphenol A, was identified as a hydrolysis product from bisphenol A dimethacrylate conversion. Cholesterol esterase induced hydrolysis of bisphenol A diglycidyl dimethacrylate yielded a Km value of 1584 muM and Vmax of 14 muM min-1. Triethyleneglycol was converted by both esterases with calculated Km values of 394 and 1311 muM for acetylcholine

  8. Anisotropy of the monomer random walk in a polymer melt: local-order and connectivity effects

    Science.gov (United States)

    Bernini, S.; Leporini, D.

    2016-05-01

    The random walk of a bonded monomer in a polymer melt is anisotropic due to local order and bond connectivity. We investigate both effects by molecular-dynamics simulations on melts of fully-flexible linear chains ranging from dimers (M  =  2) up to entangled polymers (M  =  200). The corresponding atomic liquid is also considered a reference system. To disentangle the influence of the local geometry and the bond arrangements, and to reveal their interplay, we define suitable measures of the anisotropy emphasising either the former or the latter aspect. Connectivity anisotropy, as measured by the correlation between the initial bond orientation and the direction of the subsequent monomer displacement, shows a slight enhancement due to the local order at times shorter than the structural relaxation time. At intermediate times—when the monomer displacement is comparable to the bond length—a pronounced peak and then decays slowly as t -1/2, becoming negligible when the displacement is as large as about five bond lengths, i.e. about four monomer diameters or three Kuhn lengths. Local-geometry anisotropy, as measured by the correlation between the initial orientation of a characteristic axis of the Voronoi cell and the subsequent monomer dynamics, is affected at shorter times than the structural relaxation time by the cage shape with antagonistic disturbance by the connectivity. Differently, at longer times, the connectivity favours the persistence of the local-geometry anisotropy, which vanishes when the monomer displacement exceeds the bond length. Our results strongly suggest that the sole consideration of the local order is not enough to understand the microscopic origin of the rattling amplitude of the trapped monomer in the cage of the neighbours.

  9. Synthesis and evaluation of novel siloxane-methacrylate monomers used as dentin adhesives

    Science.gov (United States)

    Ge, Xueping; Ye, Qiang; Song, Linyong; Misra, Anil; Spencer, Paulette

    2014-01-01

    Objectives The objectives of this study were to synthesize two new siloxane-methacrylate (SM) monomers for application in dentin adhesives and to investigate the influence of different functionality of the siloxane-containing monomers on the adhesive photopolymerization, water sorption, and mechanical properties. Materials and method Two siloxane-methacrylate monomers (SM1 and SM2) with four and eight methacrylate groups were synthesized. Dentin adhesives containing BisGMA, HEMA and the siloxane-methacrylate monomers were photo-polymerized. The experimental adhesives were compared with the control adhesive (HEMA/BisGMA 45/55 w/w) and characterized with regard to degree of conversion (DC), water miscibility of the liquid resin, water sorption and dynamic mechanical analysis (DMA). Results The experimental adhesives exhibited improved water miscibility as compared to the control. When cured in the presence of 12 wt % water to simulate the wet environment of the mouth, the SM-containing adhesives showed DC comparable to the control. The experimental adhesives showed higher rubbery modulus than the control under dry conditions. Under wet conditions, the mechanical properties of the formulations containing SM monomer with increased functionality were comparable with the control, even with more water sorption. Significance The concentration and functionality of the newly synthesized siloxane-methacrylate monomers affected the water miscibility, water sorption and mechanical properties of the adhesives. The experimental adhesives show improved water compatibility compared with the control. The mechanical properties were enhanced with an increase of the functionality of the siloxane-containing monomers. The results provide critical structure/property relationships and important information for future development of durable, versatile siloxane-containing dentin adhesives. PMID:24993811

  10. Thermodynamically stable amyloid-β monomers have much lower membrane affinity than the small oligomers

    Directory of Open Access Journals (Sweden)

    Bidyut eSarkar

    2013-04-01

    Full Text Available Amyloid beta (Aβ is an extracellular 39-43 residue long peptide present in the mammalian cerebrospinal fluid, whose aggregation is associated with Alzheimer’s disease. Small oligomers of Aβ are currently thought to be the key to toxicity. However, it is not clear why the monomers of Aβ are non-toxic, and at what stage of aggregation toxicity emerges. Interactions of Aβ with cell membranes is thought to be the initiator of toxicity, but membrane-binding studies with different preparations of monomers and oligomers have not settled this issue. We have earlier found that thermodynamically stable Aβ monomers emerge spontaneously from oligomeric mixtures upon long term incubation in physiological solutions (Nag et al, JBC, 2011. Here we show that the membrane-affinity of these stable Aβ monomers is much lower than that of a mixture of small oligomers (containing dimers to decamers, providing a clue to the emergence of toxicity. Fluorescently labeled Aβ40 monomers show negligible binding to cell membranes of a neuronal cell line (RN46A at physiological concentrations (250 nM, while oligomers at the same concentrations show strong binding within 30 minutes of incubation. The increased affinity most likely does not require any specific neuronal receptor, since this difference in membrane-affinity was also observed in a somatic cell-line (HEK 293T. Similar results are also obtained for Aβ42 monomers and oligomers. Minimal amount of cell death is observed at these concentrations even after 36 hours of incubation. It is likely that membrane binding precedes subsequent slower toxic events induced by Aβ. Our results a provide an explanation for the non-toxic nature of Aβ monomers, b suggest that Aβ toxicity emerges at the initial oligomeric phase, and c provide a quick assay for monitoring the benign-to-toxic transformation of Aβ.

  11. 40 CFR 35.133 - Programs eligible for inclusion.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Programs eligible for inclusion. 35.133... Programs eligible for inclusion. (a) Eligible programs. Except as provided in paragraph (b) of this section, the environmental programs eligible, in accordance with appropriation acts, for inclusion in a...

  12. 40 CFR 35.533 - Programs eligible for inclusion.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Programs eligible for inclusion. 35.533... § 35.533 Programs eligible for inclusion. (a) Eligible programs. Except as provided in paragraph (b) of this section, the environmental programs eligible for inclusion in a Performance Partnership Grant are...

  13. 43 CFR 418.9 - Reporting changes in eligible land.

    Science.gov (United States)

    2010-10-01

    ... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Reporting changes in eligible land. 418.9... Conditions of Water Delivery § 418.9 Reporting changes in eligible land. (a) Eligible land anticipated to be irrigated. (1) Anticipated changes in irrigated eligible land from the prior year will be reported to...

  14. 47 CFR 1.2114 - Reporting of eligibility event.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Reporting of eligibility event. 1.2114 Section... Competitive Bidding Proceedings General Procedures § 1.2114 Reporting of eligibility event. (a) A designated entity must seek Commission approval for all reportable eligibility events. A reportable eligibility...

  15. 20 CFR 416.204 - Redeterminations of SSI eligibility.

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Redeterminations of SSI eligibility. 416.204... AGED, BLIND, AND DISABLED Eligibility General § 416.204 Redeterminations of SSI eligibility. (a... eligible and that you are receiving the right amount of SSI benefits. This review deals with the...

  16. Thermostability of photosystem I trimers and monomers from the cyanobacterium Thermosynechococcus elongatus

    Science.gov (United States)

    Shubin, Vladimir V.; Terekhova, Irina V.; Bolychevtseva, Yulia V.; El-Mohsnawy, Eithar; Rögner, Matthias; Mäntele, Werner; Kopczak, Marta J.; Džafić, Enela

    2017-05-01

    The performance of solar energy conversion into alternative energy sources in artificial systems highly depends on the thermostability of photosystem I (PSI) complexes Terasaki et al. (2007), Iwuchukwu et al. (2010), Kothe et al. (2013) . To assess the thermostability of PSI complexes from the thermophilic cyanobacterium Thermosynechococcus elongatus heating induced perturbations on the level of secondary structure of the proteins were studied. Changes were monitored by Fourier transform infrared (FT-IR) spectra in the mid-IR region upon slow heating (1 °C per minute) of samples in D2O phosphate buffer (pD 7.4) from 20 °C to 100 °C. These spectra showed distinct changes in the Amide I region of PSI complexes as a function of the rising temperature. Absorbance at the Amide I maximum of PSI monomers (centered around 1653 cm- 1), gradually dropped in two temperature intervals, i.e. 60-75 and 80-90 °C. In contrast, absorbance at the Amide I maximum of PSI trimers (around 1656 cm- 1) dropped only in one temperature interval 80-95 °C. The thermal profile of the spectral shift of α-helices bands in the region 1656-1642 cm- 1 confirms the same two temperature intervals for PSI monomers and only one interval for trimers. Apparently, the observed absorbance changes at the Amide I maximum during heating of PSI monomers and trimers are caused by deformation and unfolding of α-helices. The absence of absorbance changes in the interval of 20-65 °C in PSI trimers is probably caused by a greater stability of protein secondary structure as compared to that in monomers. Upon heating above 80 °C a large part of α-helices both in trimers and monomers converts to unordered and aggregated structures. Spectral changes of PSI trimers and monomers heated up to 100 °C are irreversible due to protein denaturation and non-specific aggregation of complexes leading to new absorption bands at 1618-1620 cm- 1. We propose that monomers shield the denaturation sensitive sides at the

  17. Photopolymerizable phosphate acrylates as comonomers in dental adhesives with or without triclosan monomer units

    Energy Technology Data Exchange (ETDEWEB)

    Melinte, Violeta [Petru Poni Institute of Macromolecular Chemistry, 41 A Gr. Ghica Voda Alley, 700487 Iasi (Romania); Buruiana, Tinca, E-mail: tbur@icmpp.ro [Petru Poni Institute of Macromolecular Chemistry, 41 A Gr. Ghica Voda Alley, 700487 Iasi (Romania); Aldea, Horia [Gr. T. Popa University of Medicine and Pharmacy, Faculty of Dentistry, Iasi (Romania); Matiut, Simona [Praxis Medical Investigations, 33 Independence, 700102 Iasi (Romania); Silion, Mihaela; Buruiana, Emil C. [Petru Poni Institute of Macromolecular Chemistry, 41 A Gr. Ghica Voda Alley, 700487 Iasi (Romania)

    2014-01-01

    Phosphate diacrylates (CO-DAP, TMP-DAP) based on castor oil or trimethylolpropane were synthesized and evaluated in dental adhesive formulations in comparison with 3-acryloyloxy-2-hydroxypropyl methacrylate phosphate (AMP-P). In an attempt to promote antibacterial activity, another photopolymerizable monomer (TCS-UMA) containing 5-chloro-2-(2,4-dichlorophenoxy)phenol moiety (triclosan) was prepared and incorporated in adhesive resins. Each of these monomers had a molecular structure confirmed by spectral methods. The photopolymerization rates for monomers (0.063–0.088 s{sup −1}) were lower than those determined in the monomer combinations (0.116–0.158 s{sup −1}) incorporating phosphate diacrylate (11 wt.%), BisGMA (33 wt.%), TEGDMA (10 wt.%), UDMA (10 wt.%) and HEMA (15 wt.%), the degree of conversion varying between 63.4 and 74.5%. The formed copolymers showed high values for water sorption (18.65–57.02 μg/mm{sup 3}) and water solubility (3.51–13.38 μg/mm{sup 3}), and the contact angle was dependent on the presence of CO-DAP (θ{sub F1}: 66.67°), TMP-DAP (θ{sub F2}: 55.05°) or AMP-P (θ{sub F3}: 52.90°) in the photocrosslinked specimens compared to the sample without phosphate monomer (θ{sub F4}: 82.14°). The scanning electron microscopy image of the dentin–resin composite interface after applying our F1 formulation (pH: 4.1) and its light-curing for 20 s supports the evidence of the formation of the hybrid layer with the tooth structure created by self-etching approach, with no gaps or cracks in the adhesive. A comparative analysis of the adhesion achieved with commercial adhesive systems (Single Bond Universal, C-Bond) rather indicates similarities than differences between them. The addition of triclosan methacrylate (1 wt.%) into the formulation inhibited the bacterial growth of the Streptococcus mutans and Escherichia coli in the direct contact area due to the covalently linked antibacterial monomer. - Highlights: • Synthesis of

  18. Limit theorems in the imitative monomer-dimer mean-field model via Stein's method

    Science.gov (United States)

    Chen, Wei-Kuo

    2016-08-01

    We consider the imitative monomer-dimer model on the complete graph introduced in the work of Alberici et al. [J. Math. Phys. 55, 063301-1-063301-27 (2014)]. It was shown that this model is described by the monomer density and has a phase transition along certain coexistence curve, where the monomer and dimer phases coexist. More recently, it was understood [D. Alberici et al., Commun. Math. Phys. (published online, 2016)] that the monomer density exhibits the central limit theorem away from the coexistence curve and enjoys a non-normal limit theorem at criticality with normalized exponent 3/4. By reverting the model to a weighted Curie-Weiss model with hard core interaction, we establish the complete description of the fluctuation properties of the monomer density on the full parameter space via Stein's method of exchangeable pairs. Our approach recovers what were established in the work of Alberici et al. [Commun. Math. Phys. (published online, 2016)] and furthermore allows to obtain the conditional central limit theorems along the coexistence curve. In all these results, the Berry-Esseen inequalities for the Kolmogorov-Smirnov distance are given.

  19. Do CAD/CAM dentures really release less monomer than conventional dentures?

    Science.gov (United States)

    Steinmassl, Patricia-Anca; Wiedemair, Verena; Huck, Christian; Klaunzer, Florian; Steinmassl, Otto; Grunert, Ingrid; Dumfahrt, Herbert

    2017-06-01

    Computer-aided design (CAD)/computer-aided manufacturing (CAM) dentures are assumed to have more favourable material properties than conventionally fabricated dentures, among them a lower methacrylate monomer release. The aim of this study was to test this hypothesis. CAD/CAM dentures were generated from ten different master casts by using four different CAD/CAM systems. Conventional, heat-polymerised dentures served as control group. Denture weight and volume were measured; the density was calculated, and the denture surface area was assessed digitally. The monomer release after 7 days of water storage was measured by high-performance liquid chromatography. Whole You Nexteeth and Wieland Digital Dentures had significantly lower mean volume and weight than conventional dentures. Baltic Denture System and Whole You Nexteeth had a significantly increased density. Baltic Denture System had a significantly smaller surface area. None of the CAD/CAM dentures released significantly less monomer than the control group. All tested dentures released very low amounts of methacrylate monomer, but not significantly less than conventional dentures. A statistically significant difference might nevertheless exist in comparison to other, less recommendable denture base materials, such as the frequently used autopolymerising resins. CAD/CAM denture fabrication has numerous advantages. It enables the fabrication of dentures with lower resin volume and lower denture weight. Both could increase the patient comfort. Dentures with higher density might exhibit more favourable mechanical properties. The hypothesis that CAD/CAM dentures release less monomer than conventional dentures could, however, not be verified.

  20. Simulations of polymer brushes with charged end monomers under external electric fields

    Science.gov (United States)

    Ding, Huanda; Duan, Chao; Tong, Chaohui

    2017-01-01

    Using Langevin dynamics simulations, the response of neutral polymer brushes with charged terminal monomers to external electric fields has been investigated. The external electric field is equivalent to the field generated by the opposite surface charges on two parallel electrodes. The effects of charge valence of terminal monomers on the structure of double layers and overall charge balance near the two electrodes were examined. Using the charge density distributions obtained from simulations, the total electric field normal to the electrodes was calculated by numerically solving the Poisson equation. Under external electric fields, the total electric field across the two electrodes is highly non-uniform and in certain regions within the brush, the total electric field nearly vanishes. The probability distribution of electric force acting on one charged terminal monomer was obtained from simulations and how it affects the probability density distribution of terminal monomers was analyzed. The response of polymer brushes with charged terminal monomers to a strongly stretching external electric field was compared with that of uniformly charged polymer brushes.

  1. Epigallocatechin-3-Gallate Reduces Cytotoxic Effects Caused by Dental Monomers: A Hypothesis

    Science.gov (United States)

    Jiao, Yang; Ma, Sai; Wang, Yirong; Li, Jing; Shan, Lequn; Chen, Jihua

    2015-01-01

    Resin monomers from dental composite materials leached due to incomplete polymerization or biodegradation may cause contact allergies and damage dental pulp. The cytotoxicity of dental resin monomers is due to a disturbance of intracellular redox equilibrium, characterized by an overproduction of reactive oxygen species (ROS) and depletion of reduced glutathione (GSH). Oxidative stress caused by dental resin monomers leads to the disturbance of vital cell functions and induction of cell apoptosis in affected cells. The nuclear factor-erythroid 2-related factor 2 (Nrf2) pathway plays a key role in the cellular defense system against oxidative and electrophilic stress. Epigallocatechin-3-gallate (EGCG) can activate the Nrf2 pathway and induce expression of a multitude of antioxidants and phase II enzymes that can restore redox homeostasis. Therefore, here, we tested the hypothesis that EGCG-mediated protection against resin monomer cytotoxicity is mediated by activation of the Nrf2 pathway. This study will help to elucidate the mechanism of resin monomer cytotoxicity and provide information that will be helpful in improving the biocompatibility of dental resin materials. PMID:26489899

  2. Water sorption and solubility of dental composites and identification of monomers released in an aqueous environment.

    Science.gov (United States)

    Ortengren, U; Wellendorf, H; Karlsson, S; Ruyter, I E

    2001-12-01

    Water sorption and solubility of six proprietary composite resin materials were assessed, and monomers eluted from the organic matrix during water storage identified. Water sorption and solubility tests were carried out with the following storage times: 4 h, 24 h and 7, 60 and 180 days. After storage, water sorption and solubility were determined. Eluted monomers were analysed by high performance liquid chromatography (HPLC). Correlation between the retention time of the registered peak and the reference peak was observed, and UV-spectra confirmed the identity. The results showed an increase in water sorption until equilibrium for all materials with one exception. The solubility behaviour of the composite resin materials tested revealed variations, with both mass decrease and increase. The resin composition influences the water sorption and solubility behaviour of composite resin materials. The HPLC analysis of eluted components revealed that triethyleneglycol dimethacrylate (TEGDMA) was the main monomer released. Maximal monomer concentration in the eluate was observed after 7 days. During the test period, quantifiable quantities of urethanedimethacrylate (UEDMA) monomer were observed, whereas 2,2-bis[4-(2-hydroxy-3-methacryloyloxypropoxy)-phenyl]propane (Bis-GMA) was only found in detectable quantities. No detectable quantities of bisphenol-A were observed during the test period.

  3. Aβ1-42 monomers or oligomers have different effects on autophagy and apoptosis.

    Science.gov (United States)

    Guglielmotto, Michela; Monteleone, Debora; Piras, Antonio; Valsecchi, Valeria; Tropiano, Marta; Ariano, Stefania; Fornaro, Michele; Vercelli, Alessandro; Puyal, Julien; Arancio, Ottavio; Tabaton, Massimo; Tamagno, Elena

    2014-10-01

    The role of autophagy and its relationship with apoptosis in Alzheimer disease (AD) pathogenesis is poorly understood. Disruption of autophagy leads to buildup of incompletely digested substrates, amyloid-β (Aβ) peptide accumulation in vacuoles and cell death. Aβ, in turn, has been found to affect autophagy. Thus, Aβ might be part of a loop in which it is both the substrate of altered autophagy and its cause. Given the relevance of different soluble forms of Aβ1-42 in AD, we have investigated whether monomers and oligomers of the peptide have a differential role in causing altered autophagy and cell death. Using differentiated SK-N-BE neuroblastoma cells, we found that monomers hamper the formation of the autophagic BCL2-BECN1/Beclin 1 complex and activate the MAPK8/JNK1-MAPK9/JNK2 pathway phosphorylating BCL2. Monomers also inhibit apoptosis and allow autophagy with intracellular accumulation of autophagosomes and elevation of levels of BECN1 and LC3-II, resulting in an inhibition of substrate degradation due to an inhibitory action on lysosomal activity. Oligomers, in turn, favor the formation of the BCL2-BECN1 complex favoring apoptosis. In addition, they cause a less profound increase in BECN1 and LC3-II levels than monomers without affecting the autophagic flux. Thus, data presented in this work show a link for autophagy and apoptosis with monomers and oligomers, respectively. These studies are likely to help the design of novel disease modifying therapies.

  4. Interactions of univalent counterions with headgroups of monomers and dimers of an anionic surfactant.

    Science.gov (United States)

    Jakubowska, Anna

    2015-03-24

    Specific ion effects in solution are related to the hydrated ion size and ion hydration, electrostatic interactions, dispersion forces, ion effects on water structure, and ion modification of surface tension. In this study, we tried to identify which factor determines the ion specificity observed. The preference and energy of metal cations binding with the headgroups of dodecylsulfate (DS) monomers and dimers were determined by mass spectrometry. In the gas phase, cation binding to DS dimer headgroups depends strongly on the cation radius. On the other hand, the interactions between DS monomer headgroups and chaotropic ions depend on the cation polarizability, and the binding of kosmotropic cations to DS monomer headgroups strongly depends on the Gibbs free energies of ion hydration. DS dimers are related to surfactants having doubly charged headgroups, and DS monomers are related to surfactants with singly charged headgroups. Our spectrometric study of the strength of counterion binding to free monomers of a surfactant provides insight into surfactant-counterion interactions at micellar interfaces in bulk solution.

  5. Synthesis of a resin monomer-soluble polyrotaxane crosslinker containing cleavable end groups.

    Science.gov (United States)

    Seo, Ji-Hun; Nakagawa, Shino; Hirata, Koichiro; Yui, Nobuhiko

    2014-01-01

    A resin monomer-soluble polyrotaxane (PRX) crosslinker with cleavable end groups was synthesized to develop degradable photosetting composite resins. The PRX containing 50 α-cyclodextrins (α-CDs) with disulfide end groups was initially modified with n-butylamine to obtain a resin monomer-soluble PRX. The PRX containing 13 n-butyl groups per α-CD molecule was completely soluble in conventional resin monomers such as 2-hydroxyethyl methacrylate (HEMA) and urethane dimethacrylate (UDMA). The synthesized n-butyl-containing PRX was further modified with 2-aminoethyl methacrylate to provide crosslinkable acrylic groups onto PRX. The prepared resin monomer-soluble PRX crosslinker was successfully polymerized with a mixture of HEMA and UDMA to provide photosetting plastic. It was confirmed that the Vickers hardness of the prepared plastic was greatly decreased after treatment with dithiothreitol. This indicates that the resin monomer-soluble PRX crosslinker can be applied to design degradable photosetting plastics potentially used in the industrial or biomedical field.

  6. Synthesis of a resin monomer-soluble polyrotaxane crosslinker containing cleavable end groups

    Directory of Open Access Journals (Sweden)

    Ji-Hun Seo

    2014-11-01

    Full Text Available A resin monomer-soluble polyrotaxane (PRX crosslinker with cleavable end groups was synthesized to develop degradable photosetting composite resins. The PRX containing 50 α-cyclodextrins (α-CDs with disulfide end groups was initially modified with n-butylamine to obtain a resin monomer-soluble PRX. The PRX containing 13 n-butyl groups per α-CD molecule was completely soluble in conventional resin monomers such as 2-hydroxyethyl methacrylate (HEMA and urethane dimethacrylate (UDMA. The synthesized n-butyl-containing PRX was further modified with 2-aminoethyl methacrylate to provide crosslinkable acrylic groups onto PRX. The prepared resin monomer-soluble PRX crosslinker was successfully polymerized with a mixture of HEMA and UDMA to provide photosetting plastic. It was confirmed that the Vickers hardness of the prepared plastic was greatly decreased after treatment with dithiothreitol. This indicates that the resin monomer-soluble PRX crosslinker can be applied to design degradable photosetting plastics potentially used in the industrial or biomedical field.

  7. Design and Applications of Biodegradable Polyester Tissue Scaffolds Based on Endogenous Monomers Found in Human Metabolism

    Directory of Open Access Journals (Sweden)

    Devin G. Barrett

    2009-10-01

    Full Text Available Synthetic polyesters have deeply impacted various biomedical and engineering fields, such as tissue scaffolding and therapeutic delivery. Currently, many applications involving polyesters are being explored with polymers derived from monomers that are endogenous to the human metabolism. Examples of these monomers include glycerol, xylitol, sorbitol, and lactic, sebacic, citric, succinic, α-ketoglutaric, and fumaric acids. In terms of mechanical versatility, crystallinity, hydrophobicity, and biocompatibility, polyesters synthesized partially or completely from these monomers can display a wide range of properties. The flexibility in these macromolecular properties allows for materials to be tailored according to the needs of a particular application. Along with the presence of natural monomers that allows for a high probability of biocompatibility, there is also an added benefit that this class of polyesters is more environmentally friendly than many other materials used in biomedical engineering. While the selection of monomers may be limited by nature, these polymers have produced or have the potential to produce an enormous number of successes in vitro and in vivo.

  8. 76 FR 4896 - Call for Candidates

    Science.gov (United States)

    2011-01-27

    ... From the Federal Register Online via the Government Publishing Office FEDERAL ACCOUNTING STANDARDS ADVISORY BOARD Call for Candidates AGENCY: Federal Accounting Standards Advisory Board. ACTION: Notice... Federal Accounting Standards Advisory Board (FASAB) is currently seeking candidates (candidates must...

  9. 20 CFR 663.565 - May an eligible training provider lose its eligibility?

    Science.gov (United States)

    2010-04-01

    ... of title I of WIA or the WIA regulations, including 29 CFR part 37, may be removed from the list in... training to appeal a denial of eligibility under this subpart according to the requirements of 20 CFR 667... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false May an eligible training provider lose...

  10. Photoionization of cold gas phase coronene and its clusters: Autoionization resonances in monomer, dimer, and trimer and electronic structure of monomer cation

    Energy Technology Data Exchange (ETDEWEB)

    Bréchignac, Philippe, E-mail: philippe.brechignac@u-psud.fr; Falvo, Cyril; Parneix, Pascal; Pino, Thomas; Pirali, Olivier [Institut des Sciences Moléculaires d’Orsay, CNRS UMR8214, Univ Paris-Sud, F-91405 Orsay (France); Garcia, Gustavo A.; Nahon, Laurent [Synchrotron SOLEIL, L’Orme des Merisiers, Saint-Aubin, B.P. 48, F-91192 Gif-sur-Yvette (France); Joblin, Christine; Kokkin, Damian; Bonnamy, Anthony [IRAP, Université de Toulouse 3 - CNRS, 9 Av. Colonel Roche, B.P. 44346, F-31028 Toulouse Cedex 4 (France); Mulas, Giacomo [INAF - Osservatorio Astronomico di Cagliari, via della scienza 5, I-09047 Selargius (Italy)

    2014-10-28

    Polycyclic aromatic hydrocarbons (PAHs) are key species encountered in a large variety of environments such as the Interstellar Medium (ISM) and in combustion media. Their UV spectroscopy and photodynamics in neutral and cationic forms are important to investigate in order to learn about their structure, formation mechanisms, and reactivity. Here, we report an experimental photoelectron-photoion coincidence study of a prototypical PAH molecule, coronene, and its small clusters, in a molecular beam using the vacuum ultraviolet (VUV) photons provided by the SOLEIL synchrotron facility. Mass-selected high resolution threshold photoelectron (TPES) and total ion yield spectra were obtained and analyzed in detail. Intense series of autoionizing resonances have been characterized as originating from the monomer, dimer, and trimer neutral species, which may be used as spectral fingerprints for their detection in the ISM by VUV absorption spectroscopy. Finally, a full description of the electronic structure of the monomer cation was made and discussed in detail in relation to previous spectroscopic optical absorption data. Tentative vibrational assignments in the near-threshold TPES spectrum of the monomer have been made with the support of a theoretical approach based on density functional theory.

  11. Anchoring Strength of Thin Aligned-Polymer Films Formed by Liquid Crystalline Monomer

    Science.gov (United States)

    Murashige, Takeshi; Fujikake, Hideo; Ikehata, Seiichiro; Sato, Fumio

    2003-04-01

    We have evaluated the polar anchoring strength of a thin molecule-aligned polymer film formed by a liquid crystalline monomer. The polymer film was obtained by photopolymerization of the monomer oriented by a rubbed polyimide alignment layer in a chamber filled with N2 gas. We fabricated a nematic liquid crystal cell using the thin aligned-polymer films as alignment layers, and then evaluated the anchoring strength of the polymer by measuring the optical retardation curve of the cell driven by voltages. The experimental result showed that the anchoring strength was one order of magnitude lower than that of a conventional rubbed polyimide alignment layer, and decreased with increasing the cure temperature of the monomer film.

  12. Theoretical Researches on the Recognizing Characteristics of Atrazine Imprinted Polymers with Different Functional Monomers

    Institute of Scientific and Technical Information of China (English)

    LIU Jun-Bo; SUN Jia-Ni; TANG Shan-Shan; CHEN Kai-Yin; JIN Rui-Fa

    2012-01-01

    As a widely used herbicide, the threat of atrazine to both environment and health of people has become the focus. Therefore, the research and analysis of atrazine are getting more important. In this work, the MIT was used to detect atrazine theoretically. Atrazine was taken as a template molecule. MAA, MMA and TFMAA were taken as the functional monomers, respectively. The geometry optimization, the nature of hydrogen bonds, the NBO charge, and the binding energies of the imprinted molecule with the functional monomers were investigated at the B3LYP/6-31g(d,p) level. Results indicated that atrazine had the strongest interaction with TFMAA. When the ratio of atrazine and TFMAA was 1:6, the amount of H-bond formed from atrazine and TFMAA was the largest. Moreover, TFMAA owned the largest binding energy with atrazine while MMA owned the smallest. The study is helpful to interpret experiment phenomena of molecular imprinting and select better functional monomers.

  13. Protein imprinted polymer using acryloyl-β-cyclodextrin and acrylamide as monomers

    Science.gov (United States)

    Zhang, Wei; Qin, Lei; Chen, Run-Run; He, Xi-Wen; Li, Wen-You; Zhang, Yu-Kui

    2010-02-01

    A novel protein imprinted polymer was prepared using acryloyl-β-cyclodextrin (β-CD) and acrylamide as monomers on the surface of silica gel. The bovine hemoglobin was used as template and β-CD was allowed to self-assemble with the template protein through hydrogen bonding and hydrophobic interaction. Polymerization was carried out in the presence of acrylamide as an assistant monomer, which resulted in a novel protein imprinted polymer. After removing the template, imprinted cavities with the shape and spatial distribution of functional groups were formed. Bovine serum albumin (BSA) cytochrome c (Cyt) and lysozyme (Lyz) were employed as non-template proteins to test the imprinting effect and the specific binding of bovine hemoglobin to the polymer. The results of the adsorption experiments indicated that such protein imprinted polymer, which was synthesized with β-CD and acrylamide as monomers, could selectively recognize the template protein.

  14. A new label dosimetry system based on pentacosa-diynoic acid monomer for low dose applications

    Science.gov (United States)

    Abdel-Fattah, A. A.; Abdel-Rehim, F.; Soliman, Y. S.

    2012-01-01

    The dosimetric characteristics of γ-radiation sensitive labels based on polyvinyl butyral (PVB) and a conjugated diacetylene monomer, 10,12-pentacosa-diynoic acid (PCDA) have been investigated using reflectance colorimeter. Two types of labels (colourless and yellow) based on PCDA monomer were prepared using an Automatic Film Applicator System. Upon γ-ray exposure, the colourless label turns progressively blue, while the yellow colour label turns to green then to dark blue. The colour intensity of the labels is proportional to the radiation absorbed dose. The useful dose range was 15 Gy-2 kGy depending on PCDA monomer concentration. The expanded uncertainty of dose measurement of the colourless label was 6.06 (2 σ).

  15. Close-packed polymer crystals from two-monomer-connected precursors

    Science.gov (United States)

    Lee, Hong-Joon; Jo, Yong-Ryun; Kumar, Santosh; Yoo, Seung Jo; Kim, Jin-Gyu; Kim, Youn-Joong; Kim, Bong-Joong; Lee, Jae-Suk

    2016-09-01

    The design of crystalline polymers is intellectually stimulating and synthetically challenging, especially when the polymerization of any monomer occurs in a linear dimension. Such linear growth often leads to entropically driven chain entanglements and thus is detrimental to attempts to realize the full potential of conjugated molecular structures. Here we report the polymerization of two-monomer-connected precursors (TMCPs) in which two pyrrole units are linked through a connector, yielding highly crystalline polymers. The simultaneous growth of the TMCP results in a close-packed crystal in polypyrrole (PPy) at the molecular scale with either a hexagonal close-packed or face-centred cubic structure, as confirmed by high-voltage electron microscopy, and the structure that formed could be controlled by simply changing the connector. The electrical conductivity of the TMCP-based PPy is almost 35 times that of single-monomer-based PPy, demonstrating its promise for application in diverse fields.

  16. Effect of trifunctional monomers and antioxidants on crosslinking reaction of polyethylene. [Electron beams

    Energy Technology Data Exchange (ETDEWEB)

    Pyun, H.C.; Lee, Y.C.; Kim, K.J.; Yoon, B.M. (Korea Advanced Energy Research Inst., Seoul (Republic of Korea))

    1982-06-01

    The crosslinking reaction and oxidative stability of low-density polyethylene were studied in the presence of trifunctional monomers and antioxidants with electron beams. The trifunctional monomers used in this study are Trimethylolpropane triacrylate (TMPTA), Trimethylolpropane trimethacrylate (TMPTM) and Triallyl cyanurate (TAC). And the antioxidants are Irganox 1010 (Pentaerythritoltetrakis(3-(3,5-di-t-butyl-4-hydroxyphenly)-propionate)), Santonox R(4,4'-Thio-bis(3-methyl-6-t-butylphenol)), Nocrac D(N-phenyl-..beta..-naphthylamine) and Bisphenol A(4,4'-Isopropylidene bisphenol). Among the monomers, TMPTA is the best crosslinking agent and provides polyethylene with oxidative stability. Among the antioxidants, Nocrac D is the best antioxidant for polyethylene.

  17. Testing of residual monomer content reduction possibility on acrilic resins quality

    Directory of Open Access Journals (Sweden)

    Kostić Milena

    2011-01-01

    Full Text Available Poly (methyl methacrylate (PMMA is material widely used in dentistry. Despite the various methods used to initiate the polymerization of acrylic resins, the conversion of monomer to polymer is not complete thus leaving some unreacted methyl methacrylate (MMA, known as residual monomer (RM, in denture structure. RM in dental acrylic resins has deleterious effects on their mechanical properties and their biocompatibility. The objective of the work was to test the residual monomer reduction possibility by applying the appropriate postpolymerization treatment as well as to determine the effects of this reduction on pressure yields stress and surface structure characteristics of the acrylic resins. Postpolymerization treatments and water storage induced reduction of RM amount in cold-polymerized acrylic resins improved their mechanical properties and the homogenized surface structure. After the polymerization of heat-polymerized acrylic resins the post-polymerization treatments for improving the quality of this material type are not necessary.

  18. Evaluation of the level of residual monomer in acrylic denture base materials having different polymerization properties.

    Science.gov (United States)

    Kalipçilar, B; Karaağaçlioğlu, L; Hasanreisoğlu, U

    1991-09-01

    The aim of this study was to evaluate the level of residual monomer in acrylic denture base materials having different polymerization properties. The investigation included a conventional-type acrylic cured under heat and pressure, as well as a pour-type resin polymerized by an injection-moulding technique at room temperature and under pressure. It was found that the residual monomer content ranged from 0.22-0.54% in pour-type resin, and from 0.23-0.52% in routinely used resins when the specimens were analysed by high performance liquid chromatography. These findings revealed that there were no significant differences between the two types of acrylic in terms of their residual monomer content.

  19. Preparation of molecularly imprinted polymers using anacardic acid monomers derived from cashew nut shell liquid.

    Science.gov (United States)

    Philip, Joseph Y N; Buchweishaija, Joseph; Mkayula, Lupituko L; Ye, Lei

    2007-10-31

    The objective of this work was to use monomers from cashew ( Anacardium occidentale L.) nut shells to develop molecularly imprinted polymers. Cashew nut shell liquid (CNSL) is a cheap and renewable agro byproduct consisting of versatile monomers. Solvent-extracted CNSL contains over 80% anacardic acid (AnAc) with more than 90% degree of unsaturation in its C 15 side chain. From AnAc monomer, anacardanyl acrylate (AnAcr) and anacardanyl methacrylate (AnMcr) monomers were synthesized and their chemical structures were characterized by Fourier transform IR and NMR. Different imprinted bulk polymers based on AnAc, AnAcr, and AnMcr functional monomers have been prepared. In the present study, each functional monomer was separately copolymerized in toluene with ethylene glycol dimethacrylate and divinylbenzene as cross-linkers, using racemic propranolol as a model template. While the AnAc based polymer revealed a meager rebinding ability, the imprinted polymers made from AnAcr and AnMcr displayed highly specific propranolol binding. At a polymer concentration of 2 mg/mL, AnAcr and AnMcr based imprinted polymers were able to bind over 50% of trace propranolol (initial concentration 1.2 nM). Under the same condition propranolol uptake by the two nonimprinted control polymers was less than 20%. Chiral recognition properties of these polymers were further confirmed using tritium-labeled (S)-propranolol as a tracer in displacement experiments, suggesting that the apparent affinity of the imprinted chiral sites for the correct enantiomer is at least 10 times that of the mismatched (R)-propranolol. Moreover, cross reactivity studies of these polymers showed that the (S)-imprinted sites have higher cross-reactivity toward (R, S)-metoprolol than (R)-propranolol and (R)-timolol.

  20. Sustainable Poly(Ionic Liquids) for CO2 Capture Based on Deep Eutectic Monomers

    KAUST Repository

    Isik, Mehmet

    2016-10-05

    The design of high performance solid sorbent materials for CO2 capture is a technology which has been employed to mitigate global warming. However, the covalent incorporation of functionalities into polymeric supports usually involves multistep energy-intensive chemical processes. This fact makes the net CO2 balance of the materials negative even though they possess good properties as CO2 sorbents. Here we show a new family of polymers which are based on amines, amidoximes, and natural carboxylic acids and can be obtained using sustainable low energy processes. Thus, deep eutectic monomers based on natural carboxylic acids, amidoximes, and amines have been prepared by just mixing with cholinium type methacrylic ammonium monomer. The formation of deep eutectic monomers was confirmed by differential scanning calorimetry measurements. In all cases, the monomers displayed glass transition temperatures well below room temperature. Computational studies revealed that the formation of eutectic complexes lengthens the distance between the cation and the anion causing charge delocalization. The liquid nature of the resulting deep eutectic monomers (DEMs) made it possible to conduct a fast photopolymerization process to obtain the corresponding poly(ionic liquids). Materials were characterized by means of nuclear magnetic resonance, differential scanning calorimetry, thermogravimetric analysis, and X-ray diffraction to evaluate the properties of the polymers. The polymers were then used as solid sorbents for CO2 capture. It has been shown that the polymers prepared with citric acid displayed better performance both experimentally and computationally. The current endeavor showed that sustainable poly(ionic liquids) based on deep eutectic monomers can be easily prepared to produce low-energy-cost alternatives to the materials currently being researched for CO2 capture. © 2016 American Chemical Society.

  1. Intra- And Inter-Monomer Interactions are Required to Synergistically Facilitate ATP Hydrolysis in HSP90

    Energy Technology Data Exchange (ETDEWEB)

    Cunningham, C.N.; Krukenberg, K.A.; Agard, D.A.

    2009-05-12

    Nucleotide-dependent conformational changes of the constitutively dimeric molecular chaperone Hsp90 are integral to its molecular mechanism. Recent full-length crystal structures (Protein Data Bank codes 2IOQ, 2CG9, AND 2IOP) of Hsp90 homologs reveal large scale quaternary domain rearrangements upon the addition of nucleotides. Although previous work has shown the importance of C-terminal domain dimerization for efficient ATP hydrolysis, which should imply cooperativity, other studies suggest that the two ATPases function independently. Using the crystal structures as a guide, we examined the role of intra- and intermonomer interactions in stabilizing the ATPase activity of a single active site within an intact dimer. This was accomplished by creating heterodimers that allow us to differentially mutate each monomer, probing the context in which particular residues are important for ATP hydrolysis. Although the ATPase activity of each monomer can function independently, we found that the activity of one monomer could be inhibited by the mutation of hydrophobic residues on the trans N-terminal domain (opposite monomer). Furthermore, these trans interactions are synergistically mediated by a loop on the cis middle domain. This loop contains hydrophobic residues as well as a critical arginine that provides a direct linkage to the {gamma}-phosphate of bound ATP. Small angle x-ray scattering demonstrates that deleterious mutations block domain closure in the presence of AMPPNP (5{prime}-adenylyl-{beta},{gamma}-imidodiphosphate), providing a direct linkage between structural changes and functional consequences. Together, these data indicate that both the cis monomer and the trans monomer and the intradomain and interdomain interactions cooperatively stabilize the active conformation of each active site and help explain the importance of dimer formation.

  2. Synthesis, Characterization, and Cross-Linking Strategy of a Quercetin-Based Epoxidized Monomer as a Naturally-Derived Replacement for BPA in Epoxy Resins.

    Science.gov (United States)

    Kristufek, Samantha L; Yang, Guozhen; Link, Lauren A; Rohde, Brian J; Robertson, Megan L; Wooley, Karen L

    2016-08-23

    The natural polyphenolic compound quercetin was functionalized and cross-linked to afford a robust epoxy network. Quercetin was selectively methylated and functionalized with glycidyl ether moieties using a microwave-assisted reaction on a gram scale to afford the desired monomer (Q). This quercetin-derived monomer was treated with nadic methyl anhydride (NMA) to obtain a cross-linked network (Q-NMA). The thermal and mechanical properties of this naturally derived network were compared to those of a conventional diglycidyl ether bisphenol A-derived counterpart (DGEBA-NMA). Q-NMA had similar thermal properties [i.e., glass transition (Tg ) and decomposition (Td ) temperatures] and comparable mechanical properties (i.e., Young's Modulus, storage modulus) to that of DGEBA-NMA. However, it had a lower tensile strength and higher flexural modulus at elevated temperatures. The application of naturally derived, sustainable compounds for the replacement of commercially available petrochemical-based epoxies is of great interest to reduce the environmental impact of these materials. Q-NMA is an attractive candidate for the replacement of bisphenol A-based epoxies in various specialty engineering applications.

  3. Visible Light Curable Restorative Composites for Dental Applications Based on Epoxy Monomer

    Directory of Open Access Journals (Sweden)

    Alessandra Vitale

    2014-01-01

    Full Text Available A cationic photo-curable cycloaliphatic epoxy resin has been investigated as reactive monomer in blue light crosslinking process. We have demonstrated that camphorquinone is able to abstract labile hydrogen from the epoxy monomer, giving rise to the formation of carbon-centered radicals that are oxidized by the onium salt; a complete epoxy group conversion was reached after 50 s of irradiation. The presence of water up to 1 wt% was tolerated without any important detrimental effect on the kinetics of light-curing. The presence of the inorganic filler up to 65 wt% did not significantly influence the curing process.

  4. Theoretical investigation on functional monomer and solvent selection for molecular imprinting of tramadol

    Science.gov (United States)

    Fonseca, Matheus C.; Nascimento, Clebio S.; Borges, Keyller B.

    2016-02-01

    The purpose of this Letter was to study for the first time the interaction process of tramadol (TRM) with distinct functional monomers (FM) in the formation of molecular imprinted polymer (MIP), using density functional theory (DFT) calculations at B3LYP/6-31G(d,p). As result we were able to establish that the best MIP synthesis conditions are obtained with acrylic acid as FM in 1:3 molar ratio and with chloroform as solvent. This condition presented the lowest stabilization energy for the pre-polymerization complexes. Besides, the intermolecular hydrogen bonds found between the template molecule and functional monomers play a primary role to the complex stability.

  5. INFLUENCES OF WATER-SOLUBLE CATIONIC MONOMERS ON THE POLYMERIZATION RATE IN THE INVERSE EMULSION

    Institute of Scientific and Technical Information of China (English)

    HOU Sijian; HA Runhua

    1996-01-01

    This investigation deals with the free radical polymerization both of (2-methacryloyloxyethyl) trimethyl ammonium chloride (QACEMA) and of diallyldimethyl ammonium chloride (DADMAC) in inverse emulsion. The influences of some factors, such as the concentration of monomers, initiator and emulsifier are discussed. The polymerization rate equations of above two monomers can be written as follows:Rp = k[M]1.21[I]0.82[E]0.57 (for QACEMA)Rp = k′[M]1.34[I]0.90[E]0.62 (for DADMAC)

  6. Sulfonated copolyimide membranes derived from a novel diamine monomer with pendant benzimidazole groups for fuel cells

    DEFF Research Database (Denmark)

    Li, Wei; Guo, Xiaoxia; Aili, David;

    2015-01-01

    . A series of sulfonated copolyimides (SPI) are prepared via random copolymerizatio of 1,4,5,8-naphthalenetetracarboxylic dianhydride (NTDA) with a new diamine monomer with pendant benzimidazole groups, 2,2'-bis(4-(1H-benzo[d]imidazol-2-yl)phenoxy)benzidine (BIPOB), and a sulfonated diamine monomer 4,4'-bis...... pendant groups significantly improves the hydrolytic stability as well as the radical oxidative stability of the membranes. In addition, the SPI membranes exhibit high proton conductivities of 0.1 S cm(-1) in the fully hydrated state at 60 degrees C and high elastic modulus and tensile strength...

  7. One-pot synthesis of cyclic triamides with a triangular cavity from trans-stilbene and diphenylacetylene monomers.

    Science.gov (United States)

    Yokoyama, Akihiro; Maruyama, Takurou; Tagami, Kei; Masu, Hyuma; Katagiri, Kosuke; Azumaya, Isao; Yokozawa, Tsutomu

    2008-08-01

    Base-promoted self-condensation reactions of trans-stilbene and diphenylacetylene monomers bearing 4-alkylamino and 4'-methoxycarbonyl groups were investigated. Reactions of N-propyl monomers under pseudohigh-dilution conditions (a THF solution of monomer was added dropwise to a THF solution of LiHMDS) afforded the corresponding cyclic triamides in good yields. X-ray crystallographic analysis showed that these cyclic triamides possessed an almost equilateral triangle structure with a cavity surrounded by tilted benzene rings.

  8. Lattice investigation of tetraquark candidates

    Energy Technology Data Exchange (ETDEWEB)

    Berlin, Joshua; Wagner, Marc [Goethe-Universitaet Frankfurt am Main, Institut fuer Theoretische Physik (Germany); Abdel-Rehim, Abdou; Alexandrou, Constantia; Gravina, Mario; Koutsou, Giannis [Department of Physics, University of Cyprus, Nicosia (Cyprus); Computation-based Science and Technology Research Center, Cyprus Institute, Nicosia (Cyprus); Dalla Brida, Mattia [School of Mathematics, Trinity College Dublin (Ireland)

    2014-07-01

    We present the status of an ongoing long-term lattice QCD project concerned with the study of light and heavy tetraquark candidates, using a variety of different creation operators. The computation of disconnected diagrams, which is technically challenging, is discussed in detail.

  9. Candidate Prediction Models and Methods

    DEFF Research Database (Denmark)

    Nielsen, Henrik Aalborg; Nielsen, Torben Skov; Madsen, Henrik

    2005-01-01

    This document lists candidate prediction models for Work Package 3 (WP3) of the PSO-project called ``Intelligent wind power prediction systems'' (FU4101). The main focus is on the models transforming numerical weather predictions into predictions of power production. The document also outlines...

  10. Candidate gene prioritization with Endeavour.

    Science.gov (United States)

    Tranchevent, Léon-Charles; Ardeshirdavani, Amin; ElShal, Sarah; Alcaide, Daniel; Aerts, Jan; Auboeuf, Didier; Moreau, Yves

    2016-07-08

    Genomic studies and high-throughput experiments often produce large lists of candidate genes among which only a small fraction are truly relevant to the disease, phenotype or biological process of interest. Gene prioritization tackles this problem by ranking candidate genes by profiling candidates across multiple genomic data sources and integrating this heterogeneous information into a global ranking. We describe an extended version of our gene prioritization method, Endeavour, now available for six species and integrating 75 data sources. The performance (Area Under the Curve) of Endeavour on cross-validation benchmarks using 'gold standard' gene sets varies from 88% (for human phenotypes) to 95% (for worm gene function). In addition, we have also validated our approach using a time-stamped benchmark derived from the Human Phenotype Ontology, which provides a setting close to prospective validation. With this benchmark, using 3854 novel gene-phenotype associations, we observe a performance of 82%. Altogether, our results indicate that this extended version of Endeavour efficiently prioritizes candidate genes. The Endeavour web server is freely available at https://endeavour.esat.kuleuven.be/.

  11. Candidate Prediction Models and Methods

    DEFF Research Database (Denmark)

    Nielsen, Henrik Aalborg; Nielsen, Torben Skov; Madsen, Henrik

    2005-01-01

    This document lists candidate prediction models for Work Package 3 (WP3) of the PSO-project called ``Intelligent wind power prediction systems'' (FU4101). The main focus is on the models transforming numerical weather predictions into predictions of power production. The document also outlines...... the possibilities w.r.t. different numerical weather predictions actually available to the project....

  12. Candidate cave entrances on Mars

    Science.gov (United States)

    Cushing, Glen E.

    2012-01-01

    This paper presents newly discovered candidate cave entrances into Martian near-surface lava tubes, volcano-tectonic fracture systems, and pit craters and describes their characteristics and exploration possibilities. These candidates are all collapse features that occur either intermittently along laterally continuous trench-like depressions or in the floors of sheer-walled atypical pit craters. As viewed from orbit, locations of most candidates are visibly consistent with known terrestrial features such as tube-fed lava flows, volcano-tectonic fractures, and pit craters, each of which forms by mechanisms that can produce caves. Although we cannot determine subsurface extents of the Martian features discussed here, some may continue unimpeded for many kilometers if terrestrial examples are indeed analogous. The features presented here were identified in images acquired by the Mars Odyssey's Thermal Emission Imaging System visible-wavelength camera, and by the Mars Reconnaissance Orbiter's Context Camera. Select candidates have since been targeted by the High-Resolution Imaging Science Experiment. Martian caves are promising potential sites for future human habitation and astrobiology investigations; understanding their characteristics is critical for long-term mission planning and for developing the necessary exploration technologies.

  13. [Aging effect on mechanical properties in fluid resin. (Part 3) Affection of residual monomer on the surface morphology after tensile test by microscopic observation (author's transl)].

    Science.gov (United States)

    Horiuchi, A

    1981-04-01

    Affection of residual monomer on the surface morphology after tensile test was observed by an scanning microscope. Evaporation or leaching of the monomer gave big influence on the morphology of pearls and matrix. The observation suggested that the residual monomer existed mainly in the matrix. When the residual monomer disappeared, the surface morphology did not change by tensile load. It is the most important point to get good denture with fluid resin that we could decrease the residual monomer as possible.

  14. Heterogeneous glycoform separation by process chromatography: I: Monomer purification and characterization.

    Science.gov (United States)

    Li, Yi; Xu, Xuankuo; Shupe, Alan; Yang, Rong; Bai, Kevin; Das, Tapan; Borys, Michael C; Li, Zheng Jian

    2015-07-24

    Fc fusion proteins with high and low sialylation were purified and separated by preparative ion-exchange and hydrophobic interaction chromatography. Heterogeneity in sialylation and glycosylation led to variation in surface charge and hydrophobicity, and resulted in multiple distinct glycoform populations in response to various purification conditions. Monomer with high sialic acid content has higher surface charge and adsorbs stronger to ion-exchange resin, while the less sialylated monomer interacts more favorably with hydrophobic resin. Extensive biophysical characterization was carried out for purified monomers at different level of sialylation. In general, different monomeric glycoforms have different surface charge and hydrophobicity, different thermal stability, and different aggregation propensity. The surface charge corresponds well with sialic acid content, as evidenced by electrophoresis, N-link domain analysis, and zeta potential results. The sialylation also contributes to minor modification of protein size, molecular mass and tertiary structure. Notably, fluorescence emission spectra and thermal transition became less distinguishable when the monomers containing low and high sialic acid were prepared in high ionic strength solution. Such finding reiterates the fact that the electrostatic forces, which are largely dependent on sialic acid content of protein, plays a dominant role in many intra- and inter-molecular interactions. Overall, the characterization data agreed well with separation behaviors and provided valuable insight to control of glycoform profile in purification process. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. PLASMA POLYMERIZATION OF HYDROPHILIC AND HYDROPHOBIC MONOMERS FOR SURFACE MODIFICATION OF NUCLE-MICROPOROUS MEMBRANE

    Institute of Scientific and Technical Information of China (English)

    LI Xuefen; LI Zhifen; CHEN Chuanfu; WU Wenhui

    1990-01-01

    Surface modification of nucle-microporous membrane by plasma polymerization of HEMA, NVP and D4 has been studied. The hydrophilicity of membranes was increased with increasing of plasma polymerization time of hydrophilic monomers HEMA and NVP. The flow rate of water through the membrane was increased remarkably after plasma polymerization of HEMA on it.

  16. Glycerol derivatives of cutin and suberin monomers: synthesis and self-assembly.

    Science.gov (United States)

    Douliez, Jean-Paul; Barrault, Joël; Jerome, François; Heredia, Antonio; Navailles, Laurence; Nallet, Frédéric

    2005-01-01

    Glycerol derivatives of cutin and suberin monomers were synthesized by acid catalysis. Their dispersion in an aqueous solution was examined by phase contrast microscopy, neutron scattering, and solid state NMR. It is shown that the phase behavior strongly depends on the nature of the derivatives forming either lumps of aggregated membranes or well dispersed membranes.

  17. [Discussing of influence mechanism of Chinese herbal monomer on physical stability of cream].

    Science.gov (United States)

    Yin, Hui-Fu; Nie, He-Yun; Wang, Sen; Zhu, Wei-Feng; Li, Rong-Miao

    2014-10-01

    This study left flavonoids and alkaloids Chinese herbal monomer with common parent nucleus as cream base carriages drug respectively, cream base were prepared with stable span 60-tween 80 emulsification system. The near-infrared stability analysis technology was performed to quantitatively characterize the physical stability of cream. Base on the theory of gel network structure, theory of emulsification, theory of solubility parameter and theory of double layer, the influence mechanism of Chinese herbal monomer on physical stability of cream was discussed. The results showed that tetrahydropalmatine, matrine and naringenin had similar solubility parameter value with cream base material, creams prepared with those Chinese herbal monomer have higher Zeta potential value and stronger physical stability, and that those creams had similar microstructure information with cream base. However, a larger solubility parameter difference exists between baicalin, baicalein, berberine, palmatine and cream base material. Creams prepared with those Chinese herbal monomers had lower Zeta potential value and poorer physical stability, and that those creams had great different microstructure information with cream base.

  18. Regulation of the PI3K pathway through a p85a monomer-homodimer equilibrium

    KAUST Repository

    Aljedani, Safia

    2017-01-08

    The phosphatidylinositol-3-kinase a (PI3Ka) is heterodimeric enzyme that is composed of p85a regulatory subunit and a p110a catalytic subunit. PI3Ka plays a key role in cell survival, growth and differentation. Owing to its role as a key regulator, the PI3Ka pathway is the most frequently mutated pathway in human cancers, and is targeted by many viruses to insure their survival and successful reproduction. Previous studies have shown that the equilibrium of p85 monomers and dimers regulates the PI3K pathway, suggesting that interrupting this equilibrium could lead to disease development. Moreover, studies suggest that the p85a monomers and dimers have opposing effects on PI3Ka signaling as only the p85a dimers bind to the PTEN phosphatase, whereas p85a monomers bind to the catalytic p110 subunit. However, the mechanism for dimerisation is controversial, and it is unknown why PTEN or p110a bind only dimer or monomer. Therefore, we combine molecular biology, biophsical, computational and structural methods to investigate the suprosingly complex p85 dimerisation mechanism and its control by ligands. Results may inspire novel theraputic approaches.

  19. Determination of Residual Monomers in Polycarboxylate Superplasticizer Using High Performance Liquid Chromatography

    Institute of Scientific and Technical Information of China (English)

    GUO Liping; WANG Shaofeng; ZHANG Anfu; LEI Jiaheng; DU Xiaodi

    2011-01-01

    A procedure was developed for the determination of residual monomers in polycarboxylate superplasticizer (PCs) by reversed-phase high performance liquid chromatography (RP-HPLC). Four kinds of residual monomers were well separated and determined on a SinoChrom ODS-BP (C18) column with mobile phases composed of acetonitrile and phosphate buffer solution. The monomers were detected by UV detector at 205 nm and quantitatively analyzed with an external standard method. For those residual monomers, the linear response ranged from 4.0× 10-6 mol·L-1 to 2.0× 10-3 mol·L-1. The determination limit of acrylic acid, sodium methylallyl sulfonate and 2-Acrylamido-2-methylpropane sulfonic acid was 0.02× 10-5 mol·L-1, while that of methoxy-polyethylene glycol monoacrylate was 0.1 × 10-5 mol· L-1. The relative standard deviation (RSD) of high concentration samples was less than 1%, while that of the low concentration samples was between 1%-4%. The standard (additional) recovery ratio was 97.4% -104.2%.

  20. Photoligation of self-assembled DNA constructs containing anthracene-functionalized 2'-amino-LNA monomers

    DEFF Research Database (Denmark)

    Pasternak, Karol; Pasternak, Anna; Gupta, Pankaj

    2011-01-01

    Efficient synthesis of a novel anthracene-functionalized 2'-amino-LNA phosphoramidite derivative is described together with its incorporation into oligodeoxynucleotides. Two DNA strands with the novel 2'-N-anthracenylmethyl-2'-amino-LNA monomers can be effectively cross-linked by photoligation...

  1. Development of ionic gels using thiol-based monomers in ionic liquid

    Science.gov (United States)

    Ahmed, Kumkum; Naga, Naofumi; Kawakami, Masaru; Furukawa, Hidemitsu

    2016-04-01

    Ionic gels (IGs) using ionic liquids (ILs) can propose diverse applications in the field of optics, sensors and separation have opened wide prospects in materials science. ILs have attracted remarkable interest for gel polymer electrolytes and batteries based on their useful properties such as non-volatility, non-flammability, a wide electrochemical window, high thermal stability and a high ionic conductivity. The formation of gel in IL media makes it possible to immobilize ILs within organic or inorganic matrices and to take advantage of their unique properties in the solid state, thus eliminating some shortcomings related to shaping and risk of leakage. In this work for the first time we used multifunctional thiol monomers having uniform structure and good compatibility with the IL of our interest. Therefore we focused on developing thiol monomer-based IGs using multifunctional thiol monomers and acrylate crosslinkers utilizing thiol-ene reaction between monomer and crosslinking molecules in an IL medium and characterize their physico-chemical properties like thermal, conductive, mechanical properties etc.. This work has been focused mainly to improve the mechanical strength of IGs and make prospects of IGs in tribology and lubricants.

  2. The monomer-dimer problem and moment Lyapunov exponents of homogeneous Gaussian random fields

    CERN Document Server

    Vladimirov, Igor G

    2012-01-01

    We consider an "elastic" version of the statistical mechanical monomer-dimer problem on the n-dimensional integer lattice. Our setting includes the classical "rigid" formulation as a special case and extends it by allowing each dimer to consist of particles at arbitrarily distant sites of the lattice, with the energy of interaction between the particles in a dimer depending on their relative position. We reduce the free energy of the elastic dimer-monomer (EDM) system per lattice site in the thermodynamic limit to the moment Lyapunov exponent (MLE) of a homogeneous Gaussian random field (GRF) whose mean value and covariance function are the Boltzmann factors associated with the monomer energy and dimer potential. In particular, the classical monomer-dimer problem becomes related to the MLE of a moving average GRF. We outline an approach to recursive computation of the partition function for "Manhattan" EDM systems where the dimer potential is a weighted l1-distance and the auxiliary GRF is a Markov random fie...

  3. Thermosets of epoxy monomer from Tung oil fatty acids cured in two synergistic ways

    Science.gov (United States)

    A new epoxy monomer from tung oil fatty acids, glycidyl ester of eleostearic acid (GEEA), was synthesized and characterized by 1H-NMR and 13C-NMR spectroscopy. Differential scanning calorimetry analysis (DSC) and FT-IR were utilized to investigate the curing process of GEEA cured by both dienophiles...

  4. ENZYMATIC COUPLING OF THE HERBICIDE BENTAZON WITH HUMUS MONOMERS AND CHARACTERIZATION OF REACTION PRODUCTS (R823847)

    Science.gov (United States)

    To elucidate the binding mechanism of the herbicide bentazon (3-isopropyl-1H-2,1,3-benzothiadiazine-4(3H)-one 2,2-dioxide) with humic monomers in the presence of an oxidative enzyme, the reaction of bentazon with catechol, caffeic acid, protocatechuic...

  5. Unbiased charge oscillations in DNA monomer-polymers and dimer-polymers

    CERN Document Server

    Lambropoulos, Konstantinos; Morphis, Andreas; Kaklamanis, Konstantinos; Theodorakou, Marina; Simserides, Constantinos

    2015-01-01

    We call {\\it monomer} a B-DNA base-pair and examine, analytically and numerically, electron or hole oscillations in monomer- and dimer-polymers, i.e., periodic sequences with repetition unit made of one or two monomers. We employ a tight-binding (TB) approach at the base-pair level to readily determine the spatiotemporal evolution of a single extra carrier along a $N$ base-pair polymer. We study HOMO and LUMO eigenspectra as well as the mean over time probabilities to find the carrier at a particular monomer. We use the pure mean transfer rate $k$ to evaluate the easiness of charge transfer. The inverse decay length $\\beta$ for exponential fits $k(d)$, where $d$ is the charge transfer distance, and the exponent $\\eta$ for power law fits $k(N)$ are computed; generally power law fits are better. We illustrate that increasing the number of different parameters involved in the TB description, the fall of $k(d)$ or $k(N)$ becomes steeper and show the range covered by $\\beta$ and $\\eta$. Finally, both for the time-...

  6. Automatic Classification of Kepler Planetary Transit Candidates

    OpenAIRE

    McCauliff, Sean D.; Jenkins, Jon M.; Catanzarite, Joseph; Burke, Christopher J.; Coughlin, Jeffrey L.; Twicken, Joseph D.; Tenenbaum, Peter; Seader, Shawn; Li, Jie; Cote, Miles

    2014-01-01

    In the first three years of operation the Kepler mission found 3,697 planet candidates from a set of 18,406 transit-like features detected on over 200,000 distinct stars. Vetting candidate signals manually by inspecting light curves and other diagnostic information is a labor intensive effort. Additionally, this classification methodology does not yield any information about the quality of planet candidates; all candidates are as credible as any other candidate. The torrent of exoplanet disco...

  7. Synthesis and characterization of nitroaromatic peptoids: fine tuning peptoid secondary structure through monomer position and functionality.

    Science.gov (United States)

    Fowler, Sarah A; Luechapanichkul, Rinrada; Blackwell, Helen E

    2009-02-20

    N-substituted glycine oligomers, or peptoids, have emerged as an important class of foldamers for the study of biomolecular interactions and for potential use as therapeutic agents. However, the design of peptoids with well-defined conformations a priori remains a formidable challenge. New approaches are required to address this problem, and the systematic study of the role of individual monomer units in the global peptoid folding process represents one strategy. Here, we report our efforts toward this approach through the design, synthesis, and characterization of peptoids containing nitroaromatic monomer units. This work required the synthesis of a new chiral amine building block, (S)-1-(2-nitrophenyl)ethanamine (s2ne), which could be readily installed into peptoids using standard solid-phase peptoid synthesis techniques. We designed a series of peptoid nonamers that allowed us to probe the effects of this relatively electron-deficient and sterically encumbered alpha-chiral side chain on peptoid structure, namely, the peptoid threaded loop and helix. Circular dichroism spectroscopy of the peptoids revealed that the nitroaromatic monomer has a significant effect on peptoid secondary structure. Specifically, the threaded loop structure was disrupted in a nonamer containing alternating N-(S)-1-phenylethylglycine (Nspe) and Ns2ne monomers, and the major conformation was helical instead. Indeed, placement of a single Ns2ne at the N-terminal position of (Nspe)(9) resulted in a destabilized form of the threaded loop structure relative to the homononamer (Nspe)(9). Conversely, we observed that incorporation of N-(S)-1-(4-nitrophenyl)ethylglycine (Nsnp, a p-nitro monomer) at the N-terminal position stabilized the threaded loop structure relative to (Nspe)(9). Additional experiments revealed that nitroaromatic side chains can influence peptoid nonamer folding by modulating the strength of key intramolecular hydrogen bonds in the peptoid threaded loop structure. Steric

  8. 7 CFR 247.9 - Eligibility requirements.

    Science.gov (United States)

    2010-01-01

    ... Agriculture Regulations of the Department of Agriculture (Continued) FOOD AND NUTRITION SERVICE, DEPARTMENT OF AGRICULTURE CHILD NUTRITION PROGRAMS COMMODITY SUPPLEMENTAL FOOD PROGRAM § 247.9 Eligibility requirements. (a... termination of pregnancy; or (6) Elderly persons, i.e., persons at least 60 years of age. (b) What are...

  9. 45 CFR 96.85 - Income eligibility.

    Science.gov (United States)

    2010-10-01

    ... Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION BLOCK GRANTS Low-income Home Energy Assistance Program § 96.85 Income eligibility. (a) Application of poverty income guidelines and State median...-35 (42 U.S.C. 8624(b)(2)), grantees using the Federal government's official poverty income...

  10. 32 CFR 732.12 - Eligibility.

    Science.gov (United States)

    2010-07-01

    ... eligible for non-Federal medical, dental, or emergency maternity care at Government expense, Regular active... training, including leave and liberty therefrom, are considered to be in a duty status while participating... maternity care at Government expense. The only exception occurs when a member's illness or injury is...

  11. 34 CFR 682.201 - Eligible borrowers.

    Science.gov (United States)

    2010-07-01

    ... 34 Education 3 2010-07-01 2010-07-01 false Eligible borrowers. 682.201 Section 682.201 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF POSTSECONDARY EDUCATION, DEPARTMENT OF EDUCATION FEDERAL FAMILY EDUCATION LOAN (FFEL) PROGRAM General Provisions § 682.201...

  12. 23 CFR 660.511 - Eligibility.

    Science.gov (United States)

    2010-04-01

    ... determining the eligibility of proposed improvements for financing with defense access roads funds. The... certification of importance to the national defense. The criteria upon which MTMC will base its determination of... financing either in whole or in part with defense access road funds, MTMC will certify the project as...

  13. 40 CFR 35.573 - Eligible Tribe.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Eligible Tribe. 35.573 Section 35.573 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE STATE AND LOCAL ASSISTANCE Environmental Program Grants for Tribes Air Pollution Control (section 105) § 35.573...

  14. 20 CFR 628.803 - Eligibility.

    Science.gov (United States)

    2010-04-01

    ... a compensatory education program under Chapter I of title I of the Elementary and Secondary Education Act of 1965; or (iii) Has been determined to meet the eligibility requirements for free meals... tract or non-metropolitan county with a poverty rate of 30 percent or above, and in which 70 percent...

  15. 12 CFR 1805.301 - Eligible activities.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 7 2010-01-01 2010-01-01 false Eligible activities. 1805.301 Section 1805.301 Banks and Banking COMMUNITY DEVELOPMENT FINANCIAL INSTITUTIONS FUND, DEPARTMENT OF THE TREASURY... liquidity, or other means of finance: (a) Commercial facilities that promote revitalization,...

  16. 24 CFR 882.401 - Eligible properties.

    Science.gov (United States)

    2010-04-01

    ... DISABILITIES PROGRAM) SECTION 8 MODERATE REHABILITATION PROGRAMS Special Procedures for Moderate Rehabilitation... for inclusion under the Moderate Rehabilitation Program. Existing structures of various types may be... services are not eligible for assistance under the Moderate Rehabilitation Program. (2) Housing owned by...

  17. 34 CFR 668.8 - Eligible program.

    Science.gov (United States)

    2010-07-01

    ... completion and placement rates by having the certified public accountant who prepares its audit report... employer; (ii) Signed copies of State or Federal income tax forms; and (iii) Written evidence of payments of Social Security taxes. (h) Eligibility for Federal Pell Grant, ACG, National SMART Grant,...

  18. 44 CFR 79.6 - Eligibility.

    Science.gov (United States)

    2010-10-01

    ... flooding and decrease predicted flood damages, and that do not duplicate the flood prevention activities of... SECURITY INSURANCE AND HAZARD MITIGATION National Flood Insurance Program FLOOD MITIGATION GRANTS § 79.6..., addresses flood hazards. (c) Eligible activities. (1) Planning. FMA planning grants may be used to...

  19. 13 CFR 130.200 - Eligible entities.

    Science.gov (United States)

    2010-01-01

    ... or university; (3) A college or school of business, engineering, commerce or agriculture; (4) A... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Eligible entities. 130.200 Section 130.200 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION SMALL BUSINESS...

  20. 24 CFR 92.602 - Eligible activities.

    Science.gov (United States)

    2010-04-01

    ... activities. (a) Eligible activities. ADDI funds may only be used for: (1) Downpayment assistance towards the...) Rehabilitation that is completed in conjunction with the home purchase assisted with ADDI funds. The rehabilitation assisted with ADDI funds, including the reduction of lead paint hazards and the remediation...

  1. 30 CFR 884.11 - State eligibility.

    Science.gov (United States)

    2010-07-01

    ... ABANDONED MINE LAND RECLAMATION STATE RECLAMATION PLANS § 884.11 State eligibility. You, a State or Indian... for an approved State regulatory program by section 402(g)(8)(B) of SMCRA. The Navajo, Hopi, and Crow Indian tribes are exempt from the requirement for an approved regulatory program by section 405(k) of...

  2. 28 CFR 94.21 - Eligibility.

    Science.gov (United States)

    2010-07-01

    ... government not recognized by the United States; or (iii) In a country in which an official travel warning... Administration DEPARTMENT OF JUSTICE (CONTINUED) CRIME VICTIM SERVICES International Terrorism Victim Expense... terrorism or his representative, pursuant to 42 U.S.C. 10603c(a)(3)(A). For purposes of eligibility for this...

  3. 19 CFR 143.1 - Eligibility.

    Science.gov (United States)

    2010-04-01

    ... contained in § 149.5 of this chapter. If a party other than a customs broker as defined in § 111.1 of this... 19 Customs Duties 2 2010-04-01 2010-04-01 false Eligibility. 143.1 Section 143.1 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE...

  4. 7 CFR 1205.26 - Eligibility.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Eligibility. 1205.26 Section 1205.26 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... Upland cotton and imported Upland cotton in excess of the value of $2.00 per line item entry during...

  5. 34 CFR 300.804 - Eligibility.

    Science.gov (United States)

    2010-07-01

    ... 34 Education 2 2010-07-01 2010-07-01 false Eligibility. 300.804 Section 300.804 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF SPECIAL EDUCATION AND REHABILITATIVE SERVICES, DEPARTMENT OF EDUCATION ASSISTANCE TO STATES FOR THE EDUCATION OF CHILDREN...

  6. 34 CFR 668.232 - Program eligibility.

    Science.gov (United States)

    2010-07-01

    ... 34 Education 3 2010-07-01 2010-07-01 false Program eligibility. 668.232 Section 668.232 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF POSTSECONDARY EDUCATION, DEPARTMENT OF EDUCATION STUDENT ASSISTANCE GENERAL PROVISIONS Financial Assistance for Students...

  7. 7 CFR 1205.203 - Voting eligibility.

    Science.gov (United States)

    2010-01-01

    ... husband or a wife is eligible to vote if he or she shares with his or her spouse in the proceeds of the... rent or share tenant. Thus, if a husband and wife are tenants or sharecropper on a farm, jointly... rental or sharecropping agreement is written, signed by both parties, or oral, provided both husband...

  8. 7 CFR 3415.3 - Eligibility requirements.

    Science.gov (United States)

    2010-01-01

    ... private research or educational institution or organization shall be eligible to apply for and to receive..., AND EXTENSION SERVICE, DEPARTMENT OF AGRICULTURE BIOTECHNOLOGY RISK ASSESSMENT RESEARCH GRANTS PROGRAM... under grants or contracts from the Federal government; (4) Adequate financial management system and...

  9. 34 CFR 200.71 - LEA eligibility.

    Science.gov (United States)

    2010-07-01

    ... least five percent of the LEA's total population ages 5 to 17 years, inclusive. (d) Education finance... 34 Education 1 2010-07-01 2010-07-01 false LEA eligibility. 200.71 Section 200.71 Education Regulations of the Offices of the Department of Education OFFICE OF ELEMENTARY AND SECONDARY EDUCATION...

  10. 7 CFR 1948.57 - Eligible activities.

    Science.gov (United States)

    2010-01-01

    ...) Education plans; and (vi) Subdivision plans. (3) Payment of salaries of professional, technical, and... 7 Agriculture 13 2010-01-01 2009-01-01 true Eligible activities. 1948.57 Section 1948.57 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL...

  11. 8 CFR 331.2 - Eligibility.

    Science.gov (United States)

    2010-01-01

    ... Nationality DEPARTMENT OF HOMELAND SECURITY NATIONALITY REGULATIONS ALIEN ENEMIES; NATURALIZATION UNDER SPECIFIED CONDITIONS AND PROCEDURES § 331.2 Eligibility. An alien enemy may be naturalized as a citizen of... classification as an alien enemy after conducting an investigation in accordance with § 331.3; (b) The...

  12. 5 CFR 842.703 - Eligibility.

    Science.gov (United States)

    2010-01-01

    ... EMPLOYEES RETIREMENT SYSTEM-BASIC ANNUITY Alternative Forms of Annuities § 842.703 Eligibility. (a) Except... consents to the election. OPM may waive spousal consent only under the conditions prescribed by § 842.607...) Presidential appointees under section 105(a)(1), 106(a)(1), or 107 (a)(1) or (b)(1) of title 3, United...

  13. 12 CFR 1705.3 - Eligible parties.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 7 2010-01-01 2010-01-01 false Eligible parties. 1705.3 Section 1705.3 Banks and Banking OFFICE OF FEDERAL HOUSING ENTERPRISE OVERSIGHT, DEPARTMENT OF HOUSING AND URBAN... defined in section 15(a) of the Agricultural Marketing Act, 12 U.S.C. 1141j(a), with not more than...

  14. 7 CFR 760.906 - Eligible livestock.

    Science.gov (United States)

    2010-01-01

    ... or non-adult dairy cattle, beef cattle, buffalo, beefalo, catfish, crawfish, equine, sheep, goats...; (21) Non-adult beef cattle; (22) Non-adult buffalo/beefalo; (23) Non-adult dairy cattle; (24) Reindeer..., the following types of animals owned by a livestock owner are eligible livestock: (1) Adult beef bulls...

  15. 24 CFR 1003.5 - Eligible applicants.

    Science.gov (United States)

    2010-04-01

    ...) OFFICE OF ASSISTANT SECRETARY FOR PUBLIC AND INDIAN HOUSING, DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT COMMUNITY DEVELOPMENT BLOCK GRANTS FOR INDIAN TRIBES AND ALASKA NATIVE VILLAGES General Provisions § 1003.5... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Eligible applicants. 1003.5 Section...

  16. 7 CFR 1416.502 - Eligibility requirements.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Eligibility requirements. 1416.502 Section 1416.502 Agriculture Regulations of the Department of Agriculture (Continued) COMMODITY CREDIT CORPORATION, DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS 2006 EMERGENCY AGRICULTURAL DISASTER ASSISTANCE...

  17. 78 FR 2622 - Suspension of Community Eligibility

    Science.gov (United States)

    2013-01-14

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  18. 77 FR 2646 - Suspension of Community Eligibility

    Science.gov (United States)

    2012-01-19

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  19. 75 FR 5890 - Suspension of Community Eligibility

    Science.gov (United States)

    2010-02-05

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...), that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  20. 77 FR 9856 - Suspension of Community Eligibility

    Science.gov (United States)

    2012-02-21

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  1. 77 FR 7537 - Suspension of Community Eligibility

    Science.gov (United States)

    2012-02-13

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  2. 78 FR 2624 - Suspension of Community Eligibility

    Science.gov (United States)

    2013-01-14

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  3. 75 FR 4000 - Suspension of Community Eligibility

    Science.gov (United States)

    2010-01-26

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...), that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and ]...

  4. 78 FR 5734 - Suspension of Community Eligibility

    Science.gov (United States)

    2013-01-28

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  5. 76 FR 2596 - Suspension of Community Eligibility

    Science.gov (United States)

    2011-01-14

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...), that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  6. 77 FR 2650 - Suspension of Community Eligibility

    Science.gov (United States)

    2012-01-19

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  7. 75 FR 9111 - Suspension of Community Eligibility

    Science.gov (United States)

    2010-03-01

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...), that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  8. 76 FR 9666 - Suspension of Community Eligibility

    Science.gov (United States)

    2011-02-22

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...), that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  9. 42 CFR 124.3 - Eligibility.

    Science.gov (United States)

    2010-10-01

    ... authority, or public or quasi-public corporation for a project described in paragraph (b) of this section... 42 Public Health 1 2010-10-01 2010-10-01 false Eligibility. 124.3 Section 124.3 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES HEALTH RESOURCES DEVELOPMENT...

  10. 48 CFR 819.7003 - Eligibility.

    Science.gov (United States)

    2010-10-01

    ... eligibility in the VIP database. (c) A joint venture may be considered an SDVOSB or VOSB concern if (1) At least one member of the joint venture is an SDVOSB or VOSB concern, and makes the representations in... NAICS code assigned to the procurement; (3) The joint venture meets the requirements of paragraph 7...

  11. 31 CFR 321.2 - Eligible organizations.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Eligible organizations. 321.2 Section 321.2 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) FISCAL SERVICE..., building and loan associations (including cooperative banks), credit unions, cash depositories, industrial...

  12. 7 CFR 1416.601 - Eligibility requirements.

    Science.gov (United States)

    2010-01-01

    ... the appropriate state agency. Eligible producers include producers of the following types of nursery... evergreens, shade and flowering trees. (2) Stock for use as propagation in a commercial ornamental nursery operation. (3) Fruit or nut seedlings grown for sale as seed stock for commercial orchard operations...

  13. 24 CFR 574.300 - Eligible activities.

    Science.gov (United States)

    2010-04-01

    ..., information, and referral services to assist an eligible person to locate, acquire, finance and maintain... feasibility of specific housing-related initiatives); (3) Acquisition, rehabilitation, conversion, lease, and... related diseases and not to family members of these individuals; (8) Operating costs for housing...

  14. 50 CFR 80.5 - Eligible undertakings.

    Science.gov (United States)

    2010-10-01

    ...) Projects having as their purpose the restoration, conservation, management, and enhancement of wild birds...-breathing, vertebrate animals, bearing paired fins, and having material value for sport or recreation. (2... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Eligible undertakings. 80.5 Section 80.5...

  15. 50 CFR 80.2 - Eligibility.

    Science.gov (United States)

    2010-10-01

    ...) FINANCIAL ASSISTANCE-WILDLIFE SPORT FISH RESTORATION PROGRAM ADMINISTRATIVE REQUIREMENTS, PITTMAN-ROBERTSON WILDLIFE RESTORATION AND DINGELL-JOHNSON SPORT FISH RESTORATION ACTS § 80.2 Eligibility. Participation in...) Dingell-Johnson Sport Fish Restoration—Any of the States as defined in § 80.1. (b) Pittman-Robertson...

  16. 77 FR 4676 - Parents Eligible for Burial

    Science.gov (United States)

    2012-01-31

    ... of veterans and eligible family members are met by providing burial and memorialization in VA... action that is likely to result in a rule that may: (1) Have an annual effect on the economy of $100 million or more or adversely affect in a material way the economy, a sector of the economy,...

  17. 7 CFR 701.5 - Land eligibility.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 7 2010-01-01 2010-01-01 false Land eligibility. 701.5 Section 701.5 Agriculture Regulations of the Department of Agriculture (Continued) FARM SERVICE AGENCY, DEPARTMENT OF AGRICULTURE... or individual providing information regarding, for example, flood susceptibility for the land,...

  18. Monomer-dimer equilibrium in glutathione transferases: a critical re-examination.

    Science.gov (United States)

    Fabrini, Raffaele; De Luca, Anastasia; Stella, Lorenzo; Mei, Giampiero; Orioni, Barbara; Ciccone, Sarah; Federici, Giorgio; Lo Bello, Mario; Ricci, Giorgio

    2009-11-03

    Glutathione transferases (GSTs) are dimeric enzymes involved in cell detoxification versus many endogenous toxic compounds and xenobiotics. In addition, single monomers of GSTs appear to be involved in particular protein-protein interactions as in the case of the pi class GST that regulates the apoptotic process by means of a GST-c-Jun N-terminal kinase complex. Thus, the dimer-monomer transition of GSTs may have important physiological relevance, but many studies reached contrasting conclusions both about the modality and extension of this event and about the catalytic competence of a single subunit. This paper re-examines the monomer-dimer question in light of novel experiments and old observations. Recent papers claimed the existence of a predominant monomeric and active species among pi, alpha, and mu class GSTs at 20-40 nM dilution levels, reporting dissociation constants (K(d)) for dimeric GST of 5.1, 0.34, and 0.16 microM, respectively. However, we demonstrate here that only traces of monomers could be found at these concentrations since all these enzymes display K(d) values of <1 nM, values thousands of times lower than those reported previously. Time-resolved and steady-state fluorescence anisotropy experiments, two-photon fluorescence correlation spectroscopy, kinetic studies, and docking simulations have been used to reach such conclusions. Our results also indicate that there is no clear evidence of the existence of a fully active monomer. Conversely, many data strongly support the idea that the monomeric form is scarcely active or fully inactive.

  19. Efficiency of light-emitting diode and halogen units in reducing residual monomers

    Science.gov (United States)

    de Assis Ribeiro Carvalho, Felipe; Almeida, Rhita C.; Almeida, Marco Antonio; Cevidanes, Lucia H. S.; Leite, Marcia C. Amorim M.

    2011-01-01

    Introduction In this in-vitro study, we aimed to compare the residual monomers in composites beneath brackets bonded to enamel, using a light-emitting diode (LED) or a halogen unit, and to compare the residual monomers in the central to the peripheral areas of the composite. Methods Twenty bovine teeth preserved in 0.1% thymol were used in this study. Ten teeth were used to standardize the thickness of the composite film, since different thicknesses would cause different absorbance of light. Brackets were bonded to 10 bovine incisors, with the halogen light (n = 5) and the LED (n = 5). The brackets were debonded, and the remaining composite on the enamel surface was sectioned in 2 regions: peripheral (0.8 mm) and central, resulting in 2 subgroups per group: central halogen (n = 5), peripheral halogen (n = 5), central LED (n = 5), and peripheral LED (n = 5). The spectrometric analysis in the infrared region was used to measure the free monomers with the attenuated total reflectance method. Results Normal distribution was tested by using the Kolmogorov-Smirnov test. Data were compared by 2-way analysis of variance (ANOVA) at P <0.05. The LED group showed fewer residual monomers than did the halogen group (P = 0.014). No differences were found among the regions (P = 0.354), and there were no interactions between light type and region (P = 0.368). Conclusions LED leaves less residual monomer than does the halogen light, even with half of the irradiation time; there were no differences between the central and peripheral regions, and no interaction between light type and region. PMID:21055603

  20. Monomers of the Neurospora plasma membrane H+-ATPase catalyze efficient proton translocation.

    Science.gov (United States)

    Goormaghtigh, E; Chadwick, C; Scarborough, G A

    1986-06-05

    Liposomes prepared by sonication of asolectin were fractionated by glycerol density gradient centrifugation, and the small liposomes contained in the upper region of the gradients were used for reconstitution of purified, radiolabeled Neurospora plasma membrane H+-ATPase molecules by our previously published procedures. The reconstituted liposomes were then subjected to two additional rounds of glycerol density gradient centrifugation, which separate the H+-ATPase-bearing proteoliposomes from ATPase-free liposomes by virtue of their greater density. The isolated H+-ATPase-bearing proteoliposomes in two such preparations exhibited a specific H+-ATPase activity of about 11 mumol of Pi liberated/mg of protein/min, which was approximately doubled in the presence of nigericin plus K+, indicating that a large percentage of the H+-ATPase molecules in both preparations were capable of generating a transmembrane protonic potential difference sufficient to impede further proton translocation. Importantly, quantitation of the number of 105,000-dalton ATPase monomers and liposomes in the same preparations by radioactivity determination and counting of negatively stained images in the electron microscope indicated ATPase monomer to liposome ratios of 0.97 and 1.06. Because every liposome in the preparations must have had at least one ATPase monomer, these ratios indicate that very few of the liposomes had more than one, and simple calculations show that the great majority of active ATPase molecules in the preparations must have been present as proton-translocating monomers. The results thus clearly demonstrate that 105,000-dalton monomers of the Neurospora plasma membrane H+-ATPase can catalyze efficient ATP hydrolysis-driven proton translocation.

  1. Leishmaniasis: vaccine candidates and perspectives.

    Science.gov (United States)

    Singh, Bhawana; Sundar, Shyam

    2012-06-06

    Leishmania is a protozoan parasite and a causative agent of the various clinical forms of leishmaniasis. High cost, resistance and toxic side effects of traditional drugs entail identification and development of therapeutic alternatives. The sound understanding of parasite biology is key for identifying novel drug targets, that can induce the cell mediated immunity (mainly CD4+ and CD8+ IFN-gamma mediated responses) polarized towards a Th1 response. These aspects are important in designing a new vaccine along with the consideration of the candidates with respect to their ability to raise memory response in order to improve the vaccine performance. This review is an effort to identify molecules according to their homology with the host and their ability to be used as potent vaccine candidates.

  2. Enthalpy screen of drug candidates.

    Science.gov (United States)

    Schön, Arne; Freire, Ernesto

    2016-11-15

    The enthalpic and entropic contributions to the binding affinity of drug candidates have been acknowledged to be important determinants of the quality of a drug molecule. These quantities, usually summarized in the thermodynamic signature, provide a rapid assessment of the forces that drive the binding of a ligand. Having access to the thermodynamic signature in the early stages of the drug discovery process will provide critical information towards the selection of the best drug candidates for development. In this paper, the Enthalpy Screen technique is presented. The enthalpy screen allows fast and accurate determination of the binding enthalpy for hundreds of ligands. As such, it appears to be ideally suited to aid in the ranking of the hundreds of hits that are usually identified after standard high throughput screening.

  3. Candidate genes in panic disorder

    DEFF Research Database (Denmark)

    Howe, A. S.; Buttenschön, Henriette N; Bani-Fatemi, A.

    2016-01-01

    The utilization of molecular genetics approaches in examination of panic disorder (PD) has implicated several variants as potential susceptibility factors for panicogenesis. However, the identification of robust PD susceptibility genes has been complicated by phenotypic diversity, underpowered...... association studies and ancestry-specific effects. In the present study, we performed a succinct review of case-control association studies published prior to April 2015. Meta-analyses were performed for candidate gene variants examined in at least three studies using the Cochrane Mantel-Haenszel fixed......-effect model. Secondary analyses were also performed to assess the influences of sex, agoraphobia co-morbidity and ancestry-specific effects on panicogenesis. Meta-analyses were performed on 23 variants in 20 PD candidate genes. Significant associations after correction for multiple testing were observed...

  4. Toward organometallic antischistosomal drug candidates.

    Science.gov (United States)

    Hess, Jeannine; Keiser, Jennifer; Gasser, Gilles

    2015-01-01

    In the recent years, there has been a growing interest in the use of novel approaches for the treatment of parasitic diseases such as schistosomiasis. Among the different approaches used, organometallic compounds were found to offer unique opportunities in the design of antiparasitic drug candidates. A ferrocenyl derivative, namely ferroquine, has even entered clinical trials as a novel antimalarial. In this short review, we report on the studies describing the use of organometallic compounds against schistosomiasis.

  5. 24 CFR 882.803 - Project eligibility and other requirements.

    Science.gov (United States)

    2010-04-01

    ... PERSONS WITH DISABILITIES PROGRAM) SECTION 8 MODERATE REHABILITATION PROGRAMS Section 8 Moderate Rehabilitation Single Room Occupancy Program for Homeless Individuals § 882.803 Project eligibility and other... section, housing suitable for moderate rehabilitation is eligible for inclusion under this...

  6. 24 CFR 242.5 - Eligible mortgagees/lenders.

    Science.gov (United States)

    2010-04-01

    ... URBAN DEVELOPMENT MORTGAGE AND LOAN INSURANCE PROGRAMS UNDER NATIONAL HOUSING ACT AND OTHER AUTHORITIES MORTGAGE INSURANCE FOR HOSPITALS General Eligibility Requirements § 242.5 Eligible mortgagees/lenders. The...

  7. Reactivity of vinyl ethers and vinyl ribosides in UV-initiated free radical copolymerization with acceptor monomers.

    Science.gov (United States)

    Pichavant, Loic; Guillermain, Céline; Coqueret, Xavier

    2010-09-13

    The reactivity of various vinyl ethers and vinyloxy derivatives of ribose in the presence of diethyl fumarate or diethyl maleate was investigated for evaluating the potential of donor-acceptor-type copolymerization applied to unsaturated monomers derived from renewable feedstock. The photochemically induced polymerization of model monomer blends in the bulk state was monitored by infrared spectroscopy. The method allowed us to examine the influence of monomer pair structure on the kinetic profiles. The simultaneous consumption of both monomers was observed, supporting an alternating copolymerization mechanism. A lower reactivity of the blends containing maleates compared with fumarates was confirmed. The obtained kinetic data revealed a general correlation between the initial polymerization rate and the Hansen parameter δ(H) associated with the H-bonding aptitude of the donor monomer.

  8. Guidelines To Select the N-Heterocyclic Carbene for the Organopolymerization of Monomers with a Polar Group

    KAUST Repository

    Falivene, Laura

    2017-02-13

    We report on the DFT stability of zwitterion and spirocycle adducts of five polar monomers with nine N-heterocyclic carbenes (NHC), covering the most typical classes of monomers and NHCs used in organopolymerization. Results indicate that the relative stability of the two adducts is dominated by the singlet-triplet energy gap of the free NHC, with low energy gaps favoring the spirocycle adduct, while high energy gaps favor the zwitterionic adduct. This basic structure/property relationship can be tuned by the hindrance of the NHC and the nature of the monomer. In addition to rationalize existing systems, the 45 NHC/monomer combinations we examined can be used as a guideline to predict the behavior of a new NHC/monomer combination.

  9. US Department of Energy wind turbine candidate site program: the regulatory process

    Energy Technology Data Exchange (ETDEWEB)

    Greene, M.R.; York, K.R.

    1982-06-01

    Sites selected in 1979 as tentative sites for installation of a demonstration MOD-2 turbine are emphasized. Selection as a candidate site in this program meant that the US Department of Energy (DOE) designated the site as eligible for a DOE-purchased and installed meteorological tower. The regulatory procedures involved in the siting and installation of these meteorological towers at the majority of the candidate sites are examined. An attempt is also made, in a preliminary fashion, to identify the legal and regulatory procedures that would be required to put up a turbine at each of these candidate sites. The information provided on each of these sites comes primarily from utility representatives, supplemented by conversations with state and local officials. The major findings are summarized on the following: federal requirements, state requirements, local requirements, land ownership, wind rights, and public attitudes.

  10. 45 CFR 233.51 - Eligibility of sponsored aliens.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 2 2010-10-01 2010-10-01 false Eligibility of sponsored aliens. 233.51 Section... CONDITIONS OF ELIGIBILITY IN FINANCIAL ASSISTANCE PROGRAMS § 233.51 Eligibility of sponsored aliens... affidavit(s) of support or similar agreement on behalf of an alien (who is not the child of the sponsor or...

  11. 14 CFR 61.83 - Eligibility requirements for student pilots.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Eligibility requirements for student pilots... TRANSPORTATION (CONTINUED) AIRMEN CERTIFICATION: PILOTS, FLIGHT INSTRUCTORS, AND GROUND INSTRUCTORS Student Pilots § 61.83 Eligibility requirements for student pilots. To be eligible for a student...

  12. 5 CFR 870.301 - Eligibility for life insurance.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Eligibility for life insurance. 870.301... REGULATIONS (CONTINUED) FEDERAL EMPLOYEES' GROUP LIFE INSURANCE PROGRAM Eligibility § 870.301 Eligibility for life insurance. (a) Each nonexcluded employee is automatically insured for Basic insurance unless...

  13. 7 CFR 632.13 - Eligible lands and water.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 6 2010-01-01 2010-01-01 false Eligible lands and water. 632.13 Section 632.13... lands and water. Lands and water eligible for reclamation are those that were mined for coal or were... lands and water are not eligible if: (a) There is continuing reclamation responsibility on the part of...

  14. 29 CFR 1908.3 - Eligibility and funding.

    Science.gov (United States)

    2010-07-01

    ... remaining range of voluntary compliance activities referred to in 29 CFR 1902.4(c)(2)(xiii), will not be... 29 Labor 5 2010-07-01 2010-07-01 false Eligibility and funding. 1908.3 Section 1908.3 Labor... CONSULTATION AGREEMENTS § 1908.3 Eligibility and funding. (a) State eligibility. Any state may enter into...

  15. 40 CFR 35.135 - Activities eligible for funding.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Activities eligible for funding. 35.135... Activities eligible for funding. (a) A recipient may use a Performance Partnership Grant, subject to the requirements of paragraph (c) of this section, to fund any activity that is eligible for funding under at...

  16. 44 CFR 206.223 - General work eligibility.

    Science.gov (United States)

    2010-10-01

    ... eligible applicant. (b) Private nonprofit facilities. To be eligible, all private nonprofit facilities must be owned and operated by an organization meeting the definition of a private nonprofit organization... by an eligible applicant, as defined in § 206.222, must be owned by a private nonprofit...

  17. 24 CFR 5.510 - Documents of eligible immigration status.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false Documents of eligible immigration... Noncitizens § 5.510 Documents of eligible immigration status. (a) General. A responsible entity shall request and review original documents of eligible immigration status. The responsible entity shall...

  18. 45 CFR 1611.7 - Manner of determining financial eligibility.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false Manner of determining financial eligibility. 1611.7 Section 1611.7 Public Welfare Regulations Relating to Public Welfare (Continued) LEGAL SERVICES CORPORATION FINANCIAL ELIGIBILITY § 1611.7 Manner of determining financial eligibility. (a)(1) In making...

  19. 5 CFR 9901.323 - Eligibility for general salary increase.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Eligibility for general salary increase... Increases § 9901.323 Eligibility for general salary increase. (a) Employees with a current rating of record... recently completed appraisal period are eligible to receive an approved general salary increase in their...

  20. 46 CFR 308.401 - Eligibility for insurance.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 8 2010-10-01 2010-10-01 false Eligibility for insurance. 308.401 Section 308.401 Shipping MARITIME ADMINISTRATION, DEPARTMENT OF TRANSPORTATION EMERGENCY OPERATIONS WAR RISK INSURANCE War Risk Builder's Risk Insurance § 308.401 Eligibility for insurance. A vessel is eligible for...

  1. 44 CFR 302.3 - Documentation of eligibility.

    Science.gov (United States)

    2010-10-01

    ... 44 Emergency Management and Assistance 1 2010-10-01 2010-10-01 false Documentation of eligibility... PROGRAM (EMA) § 302.3 Documentation of eligibility. In order to remain eligible for Federal financial... shall forward the letter, together with all available pertinent documentation from the...

  2. 12 CFR 615.5120 - Purchase eligibility requirement.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Purchase eligibility requirement. 615.5120... AFFAIRS, LOAN POLICIES AND OPERATIONS, AND FUNDING OPERATIONS Other Funding § 615.5120 Purchase eligibility requirement. (a) Limitations. Eligibility to purchase Farm Credit Investment Bonds shall...

  3. 45 CFR 1626.7 - Verification of eligible alien status.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false Verification of eligible alien status. 1626.7... CORPORATION RESTRICTIONS ON LEGAL ASSISTANCE TO ALIENS § 1626.7 Verification of eligible alien status. (a) An alien seeking representation shall submit appropriate documents to verify eligibility, unless the...

  4. 7 CFR 1463.107 - Payment to eligible quota holders.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Payment to eligible quota holders. 1463.107 Section... PROGRAM Tobacco Transition Payment Program § 1463.107 Payment to eligible quota holders. (a) The total amount of contract payments that may be made to an eligible quota holder shall be the product obtained...

  5. 7 CFR 1463.103 - Eligible quota holder.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Eligible quota holder. 1463.103 Section 1463.103... Transition Payment Program § 1463.103 Eligible quota holder. (a) CCC will make a payment under this subpart to a person determined by CCC to be an eligible quota holder, as defined in § 1463.102. (b)...

  6. 20 CFR 416.1100 - Income and SSI eligibility.

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Income and SSI eligibility. 416.1100 Section..., BLIND, AND DISABLED Income General § 416.1100 Income and SSI eligibility. You are eligible for supplemental security income (SSI) benefits if you are an aged, blind, or disabled person who meets the...

  7. 50 CFR 296.4 - Claims eligible for compensation.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 7 2010-10-01 2010-10-01 false Claims eligible for compensation. 296.4... compensation. (a) Claimants. Damage or loss eligible for Fund compensation must be suffered by a commercial fisherman. (b) Damage or loss of fishing gear. Damage or loss is eligible for Fund compensation if it...

  8. 45 CFR 1639.4 - Permissible representation of eligible clients.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false Permissible representation of eligible clients... CORPORATION WELFARE REFORM § 1639.4 Permissible representation of eligible clients. Recipients may represent an individual eligible client who is seeking specific relief from a welfare agency. ...

  9. 45 CFR 1160.4 - Eligibility for international exhibitions.

    Science.gov (United States)

    2010-10-01

    ... AND ARTIFACTS INDEMNITY ACT § 1160.4 Eligibility for international exhibitions. An indemnity agreement...- and domestic-owned objects in an international exhibition. The foreign-owned objects are eligible for indemnity coverage under paragraph (a) of this section, and the domestic-owned objects may be eligible...

  10. 19 CFR 143.43 - RLF eligibility criteria.

    Science.gov (United States)

    2010-04-01

    ... TREASURY (CONTINUED) SPECIAL ENTRY PROCEDURES Remote Location Filing § 143.43 RLF eligibility criteria. (a) Automation criteria. To be eligible for RLF, a licensed customs broker or importer of record must be: (1... 19 Customs Duties 2 2010-04-01 2010-04-01 false RLF eligibility criteria. 143.43 Section...

  11. Photopolymerizable phosphate acrylates as comonomers in dental adhesives with or without triclosan monomer units.

    Science.gov (United States)

    Melinte, Violeta; Buruiana, Tinca; Aldea, Horia; Matiut, Simona; Silion, Mihaela; Buruiana, Emil C

    2014-01-01

    Phosphate diacrylates (CO-DAP, TMP-DAP) based on castor oil or trimethylolpropane were synthesized and evaluated in dental adhesive formulations in comparison with 3-acryloyloxy-2-hydroxypropyl methacrylate phosphate (AMP-P). In an attempt to promote antibacterial activity, another photopolymerizable monomer (TCS-UMA) containing 5-chloro-2-(2,4-dichlorophenoxy)phenol moiety (triclosan) was prepared and incorporated in adhesive resins. Each of these monomers had a molecular structure confirmed by spectral methods. The photopolymerization rates for monomers (0.063-0.088s(-1)) were lower than those determined in the monomer combinations (0.116-0.158s(-1)) incorporating phosphate diacrylate (11wt.%), BisGMA (33wt.%), TEGDMA (10wt.%), UDMA (10wt.%) and HEMA (15wt.%), the degree of conversion varying between 63.4 and 74.5%. The formed copolymers showed high values for water sorption (18.65-57.02μg/mm(3)) and water solubility (3.51-13.38μg/mm(3)), and the contact angle was dependent on the presence of CO-DAP (θF1: 66.67°), TMP-DAP (θF2: 55.05°) or AMP-P (θF3: 52.90°) in the photocrosslinked specimens compared to the sample without phosphate monomer (θF4: 82.14°). The scanning electron microscopy image of the dentin-resin composite interface after applying our F1 formulation (pH: 4.1) and its light-curing for 20s supports the evidence of the formation of the hybrid layer with the tooth structure created by self-etching approach, with no gaps or cracks in the adhesive. A comparative analysis of the adhesion achieved with commercial adhesive systems (Single Bond Universal, C-Bond) rather indicates similarities than differences between them. The addition of triclosan methacrylate (1wt.%) into the formulation inhibited the bacterial growth of the Streptococcus mutans and Escherichia coli in the direct contact area due to the covalently linked antibacterial monomer.

  12. From monomer to monolayer: a global optimisation study of (ZnO)n nanoclusters on the Ag surface.

    Science.gov (United States)

    Demiroglu, Ilker; Woodley, Scott M; Sokol, Alexey A; Bromley, Stefan T

    2014-12-21

    We employ global optimisation to investigate how oxide nanoclusters of increasing size can best adapt their structure to lower the system energy when interacting with a realistic extended metal support. Specifically, we focus on the (ZnO)@Ag(111) system where experiment has shown that the infinite Ag(111)-supported ZnO monolayer limit corresponds to an epitaxially 7 : 8 matched graphene-like (Zn(3)O(3))-based hexagonal sheet. Using a two-stage search method based on classical interatomic potentials and then on more accurate density functional theory, we report global minina candidate structures for Ag-supported (ZnO)n cluster with sizes ranging from n = 1-24. Comparison with the respective global minina structure of free space (ZnO)n clusters reveals that the surface interaction plays a decisive role in determining the lowest energy Ag-supported (ZnO)n cluster structures. Whereas free space (ZnO)n clusters tend to adopt cage-like bubble structures as they grow larger, Ag-supported (ZnO)n clusters of increasing size become progressively more like planar cuts from the infinite graphene-like ZnO single monolayer. This energetic favourability for planar hexagonal Ag-supported clusters over their 3D counterparts can be partly rationalised by the ZnO-Ag(111) epitaxial matching and the increased number of close interactions with the Ag surface. Detailed analysis shows that this tendency can also be attributed to the capacity of 2D clusters to distort to improve their interaction with the Ag surface relative to more rigid 3D bubble cluster isomers. For the larger sized clusters we find that the adsorption energies and most stable structural types appear to be rather converged confirming that our study makes a bridge between the Ag-supported ZnO monomer and the infinite Ag-supported ZnO monolayer.

  13. The FRCR 2B examination: a survey of candidate perceptions and experiences

    Energy Technology Data Exchange (ETDEWEB)

    Yeung, A., E-mail: andrewyeung@hotmail.co [Department of Radiology, Freeman Hospital, Newcastle upon Tyne (United Kingdom); Booth, T.C. [Department of Radiology, Royal Free Hospital, London (United Kingdom); Jacob, K. [Department of Radiology, Weston General Hospital, Weston-super-Mare (United Kingdom); McCoubrie, P. [Department of Radiology, Southmead Hospital, Bristol (United Kingdom); McKnight, L. [Department of Radiology, Morriston Hospital, Swansea (United Kingdom)

    2011-05-15

    Aim: To survey the views of recent candidates of the Fellowship of the Royal College of Radiologists (FRCR) 2B examination with reference to assessment validity, reliability, and acceptability. Materials and methods: One thousand, two hundred and four UK radiology trainees and consultants were invited to complete an automated internet questionnaire regarding their experiences and perceptions of the FRCR 2B examination. The questionnaire was informed by a review of the literature. Eligible participants were candidates who had taken the examination within the previous 3 years. Results: Four hundred and ninety-seven out of 1204 (41%) responses were received; of which 258/497 (52% of respondents) were eligible for inclusion into the study. The rapid reporting component is perceived to be significantly fairer than the oral section (82 versus 70% agree; p < 0.001). The oral component fared poorly in perceived performance-reducing anxiety levels but well in questions relating to validity and reliability. Female candidates are more likely to find the FRCR 2B unfair (p = 0.01) and experience performance-reducing anxiety (p < 0.001) than males. No gender differences were observed in first-time pass rates (p = 0.6). Candidate first language did not affect anxiety levels (p = 0.9) or first-time pass rates (p = 0.06). Only 12% of candidates agreed that the oral examination should move to an objective structured clinical format. Conclusion: Candidates score the FRCR 2B examination well in test validity with little desire for change to the oral examination format. Efforts to help reduce anxiety levels in the oral component would improve perceived fairness.

  14. Prevalence of substance-related disorders in heart transplantation candidates.

    Science.gov (United States)

    Sirri, L; Potena, L; Masetti, M; Tossani, E; Grigioni, F; Magelli, C; Branzi, A; Grandi, S

    2007-01-01

    Substance abuse cessation is one of the leading factors in determining the eligibility for the heart transplantation waiting list, as noncompliance with this issue may seriously endanger posttransplantation outcomes. Yet, the prevalence of substance-related disorders among candidates for heart transplantation has not been evaluated enough. Eighty three heart transplantation candidates were assessed for prior or current substance-related disorders through the Structured Clinical Interview for mental disorders according to DSM-IV. A prior history of at least one substance-related disorder was found in 64% of patients, with nicotine dependence as the most prevalent diagnosis (61.4% of the sample). Ten subjects were currently smokers, despite heart failure. A prior history of alcohol abuse and caffeine intoxication was found in 9.6% and 2.4% of patients, respectively. Substance abuse or dependence behaviors should be monitored during all the phases of heart transplantation program. Early identification of current substance-related disorders may allow better allocation of organ resources and proper lifestyle modification programs provision. A prior history of substance-related disorders should alert physicians to assess patients for possible relapse, especially after transplantation. The inclusion of a specialist in the assessment and treatment of substance-related disorders in the heart transplantation unit may reduce the risk of unsuccessful outcomes due to noncompliance with an adequate lifestyle.

  15. Cyclosophorohexadecaose and succinoglycan monomers as catalytic carbohydrates for the Strecker reaction.

    Science.gov (United States)

    Lee, Sanghoo; Cho, Eunae; Kwon, Chanho; Jung, Seunho

    2007-12-10

    Some microbial carbohydrates have been used as catalysts for the multicomponent Strecker reaction using trimethylsilyl cyanide (TMSCN). Alpha-Cyclosophorohexadecaose (alpha-C16) derived from Xanthomonas species and succinoglycan monomers derived from Rhizobium species acted as catalytic carbohydrates in the mixture solutions of methanol and water. Malonaldehyde bis(phenylimine) as a substrate was completely converted (yield: 100%) into its product to 100% by both alpha-C16 and the succinoglycan monomer (M2), having acetyl, pyruvyl, and succinyl groups as substituents after 1h. The catalytic abilities of the carbohydrates were dependent on the inherent structures of the substrates used in this study, where substrate 1 having a symmetrical structure rather than the others was favorably reacted with the alpha-C16 and M2. Through this study, we suggest that the microbial carbohydrates used in this study could be expected to be environmentally-benign catalysts for the synthesis of alpha-aminonitriles.

  16. Facile synthesis of polyester dendrimers from sequential click coupling of asymmetrical monomers.

    Science.gov (United States)

    Ma, Xinpeng; Tang, Jianbin; Shen, Youqing; Fan, Maohong; Tang, Huadong; Radosz, Maciej

    2009-10-21

    Polyester dendrimers are attractive for in vivo delivery of bioactive molecules due to their biodegradability, but their synthesis generally requires multistep reactions with intensive purifications. A highly efficient approach to the synthesis of dendrimers by simply "sticking" generation by generation together is achieved by combining kinetic or mechanistic chemoselectivity with click reactions between the monomers. In each generation, the targeted molecules are the major reaction product as detected by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). The only separation needed is to remove the little unreacted monomer by simple precipitation or washing. This simple clicklike process without complicated purification is particularly suitable for the synthesis of custom-made polyester dendrimers.

  17. Mangrove tannins and their flavanoid monomers as alternative steel corrosion inhibitors in acidic medium

    Energy Technology Data Exchange (ETDEWEB)

    Rahim, Afidah A. [School of Chemical Sciences, University Sains Malaysia, 11800 Penang (Malaysia)]. E-mail: afidah@usm.my; Rocca, E. [Laboratoire de Chimie du Solide Mineral, Universite Henri Poincare, Nancy I BP 239, 54506 Vandoeuvre Les Nancy (France); Steinmetz, J. [Laboratoire de Chimie du Solide Mineral, Universite Henri Poincare, Nancy I BP 239, 54506 Vandoeuvre Les Nancy (France); Kassim, M.J. [School of Chemical Sciences, University Sains Malaysia, 11800 Penang (Malaysia); Adnan, R. [School of Chemical Sciences, University Sains Malaysia, 11800 Penang (Malaysia); Sani Ibrahim, M. [School of Chemical Sciences, University Sains Malaysia, 11800 Penang (Malaysia)

    2007-02-15

    The inhibitive behaviour on steel of flavanoid monomers that constitute mangrove tannins namely catechin, epicatechin, epigallocatechin and epicatechingallate was investigated in an aerated HCl solution via electrochemical methods. The monomers were found to be mainly cathodic inhibitors and the inhibition efficiency was dependent on concentration. To explain the adsorptive behaviour of the molecules on the steel surface, a semiempirical approach involving quantum chemical calculations using HyperChem 6.0 was undertaken. The HOMO electronic density of the molecule was used to explain the inhibiting mechanism. The most probable adsorption centers were found in the vicinity of the phenolic groups. In a second part, the use of mangrove tannin, extracted from the mangrove barks as steel corrosion inhibitors in acidic media was investigated and its inhibitive efficiency was compared with that of commercial mimosa, quebracho and chestnut tannins. The inhibitive performance of mangrove tannins was comparable to the other tannins investigated, indicating their potential in corrosion protection.

  18. Investigation on Vibrational Spectra and Structures of 4-Mercaptopyridine Monomer and Its Dihydrate

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The optimized molecular structures and vibrational frequencies of 4-mercaptopyridine(4MPY) monomer and its dihydrate were studied by means of the density functional theory(DFT), viz. B3LYP method with the 6-311++G(d,p) basis set. On the basis of the calculations, the assignments of the vibrational spectra of the monomer and the dihydrate were performed, and so were investigated the changes in the structure and the vibrational spectrum of the dihydrate as well as the intermolecular force resulting in the formation of the dihydrate. The calculated results show that each of the water molecule planes is vertical to the pyridine ring plane in the dihydrate that is formed via the H-bonds between 4MPY and water molecules. Furthermore, the structure and the vibrational spectrum of 4MPY can be consi-derably affected by the water molecules.

  19. Direct Arylation Strategies in the Synthesis of π-Extended Monomers for Organic Polymeric Solar Cells

    Directory of Open Access Journals (Sweden)

    Andrea Nitti

    2016-12-01

    Full Text Available π-conjugated macromolecules for organic polymeric solar cells can be rationally engineered at the molecular level in order to tune the optical, electrochemical and solid-state morphology characteristics, and thus to address requirements for the efficient solid state device implementation. The synthetic accessibility of monomers and polymers required for the device is getting increasing attention. Direct arylation reactions for the production of the π-extended scaffolds are gaining importance, bearing clear advantages over traditional carbon-carbon forming methodologies. Although their use in the final polymerization step is already established, there is a need for improving synthetic accessibility to implement them also in the monomer synthesis. In this review, we discuss recent examples highlighting this useful strategy.

  20. Composition and Process for Retarding the Premature Aging of PMR Monomer Solutions and PMR Prepegs

    Science.gov (United States)

    Alston, William B. (Inventor); Gahn, Gloria S. (Inventor)

    2000-01-01

    Polyimides are derived from solutions of at least one low-boiling organic solvent, e.g. isopropanol containing a mixture of polyimide-forming monomers. The monomeric solutions have an extended shelf life at ambient (room) temperatures as high as 80 C, and consist essentially of a mixture of monoalkyl ester-acids, alkyl diester-diacids and aromatic polyamines wherein the alkyl radicals of the esteracids are derived from lower molecular weight aliphatic secondary alcohols having 3 to 5 carbon atoms per molecule such as isopropanol, secondary butanol, 2-methyl-3-butanol, 2 pentanol or 3-pentanol. The solutions of the polyimide-forming monomers have a substantially improved shelf-life and are particularly useful in the aerospace and aeronautical industry for the preparation of polyimide reinforced fiber composites such as the polyimide cured carbon composites used in jet engines, missiles, and for other high temperature applications.

  1. A cleaner two-step synthesis of high purity diallyldimethylammonium chloride monomers for flocculant preparation

    Institute of Scientific and Technical Information of China (English)

    TIAN Bing-hui; FAN Bin; PENG Xian-jia; LUAN Zhao-kun

    2005-01-01

    In order to improve the flocculation efficiency of polydiallyldimethylammonium chloride (PDADMAC), high molecular weight PDADMAC should be prepared from high purity diallyldimethylammonium chloride(DADMAC) monomers. In this paper, a cleaner method with microwave irradiation and alkali solidification was proposed for preparing high pure DADMAC by selective heating under low temperature, and the prepared high purity DADMAC is characterized using FTIR and atomic absorption spectrometry. The new method provides a solution to the key technical problem of PDADMAC synthesis. Comparing with the conventional methods, the results showed that the advantages of the novel synthesis include: (a) high purity DADMAC is improved from 57% to 71%; (b) reaction time of tertiary amine preparation is shortened from 6 h to 7 min; (c) water instead of acetone was used as reaction medium; (d) toxic by-products,wastewater and waste gas are eliminated. Flocculant made from the synthesized high purity DADMAC monomers was proved more efficient in flocculation tests.

  2. Structure and Properties of Silk Fibers Grafted with Vinyl Siloxane Monomer

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Silk fibers were grafted with a novel vinyl siloxane monomer. The properties of silk with different grafting yield were discussed. The results showed that the crease recovery of grafted silk fabric is improved significantly, handle of grafted silk is softer, and grafting has no influence on strength of silk. Graft with low grafting yield has no effect on dyeing properties of silk. The results of IR, SEM photographs and amino acid analysis indicate that the monomer combines with silk fiber by physical sediment and chemical bond, the grafting reactions mainly oecurred on Ser., His. and Arg. of silk fibers, and ester crosslinking forms between silanol and Asp., Glu. of silk molecular side chains. X-ray diffraction patterns of silk fibers suggest that the grafting has no effect on the crystalline regions.

  3. Copolymerization of Propylene and Polar Monomers Using Pd/IzQO Catalysts.

    Science.gov (United States)

    Nakano, Ryo; Nozaki, Kyoko

    2015-09-02

    Palladium catalysts bearing imidazo[1,5-a]quinolin-9-olate-1-ylidene (IzQO) ligands polymerize α-olefins while incorporating polar monomers. The steric environment provided by N-heterocyclic-carbene (NHC) enables regioselective insertion of α-olefins and polar monomers, yielding polypropylene, propylene/allyl carboxylate copolymers, and propylene/methyl acrylate copolymer. Known polymerization catalysts bearing NHC-based ligands decompose rapidly, whereas the present catalyst is durable because of structural confinement, wherein the NHC-plane is coplanar to the metal square plane. The present catalyst system enables facile access to a new class of functionalized polyolefins and helps conceive a new fundamental principle for designing NHC-based ligands.

  4. NGAL (Lcn2) monomer is associated with tubulointerstitial damage in chronic kidney disease.

    Science.gov (United States)

    Nickolas, Thomas L; Forster, Catherine S; Sise, Meghan E; Barasch, Nicholas; Solá-Del Valle, David; Viltard, Melanie; Buchen, Charles; Kupferman, Shlomo; Carnevali, Maria Luisa; Bennett, Michael; Mattei, Silvia; Bovino, Achiropita; Argentiero, Lucia; Magnano, Andrea; Devarajan, Prasad; Mori, Kiyoshi; Erdjument-Bromage, Hediye; Tempst, Paul; Allegri, Landino; Barasch, Jonathan

    2012-09-01

    The type and the extent of tissue damage inform the prognosis of chronic kidney disease (CKD), but kidney biopsy is not a routine test. Urinary tests that correlate with specific histological findings might serve as surrogates for the kidney biopsy. We used immunoblots and ARCHITECT-NGAL assays to define the immunoreactivity of urinary neutrophil gelatinase-associated lipocalin (NGAL) in CKD, and we used mass spectroscopy to identify associated proteins. We analyzed kidney biopsies to determine whether specific pathological characteristics associated with the monomeric NGAL species. Advanced CKD urine contained the NGAL monomer as well as novel complexes of NGAL. When these species were separated, we found a significant correlation between the NGAL monomer and glomerular filtration rate (r=-0.53, Phistology that typifies progressive, severe CKD.

  5. Penelitian penggunaan monomer n-butil akrilat untuk peningkatan mutu kulit secara iradiasi

    Directory of Open Access Journals (Sweden)

    Dwi Wahini Nurhajati

    1996-06-01

    Full Text Available Research on the utilization of n-butyl acrylate monomer for quality improvement leather by irradiation cobalt-60 gamma-rays is carried out as follows: Javanese crust hide was impregnated with water emulsions of n-butyl acrylate monomer for 2 hours, packed in to poly ethylene bags, sealed, then irradiated by cobalt-60 gamma rays (doses : 5 to 25 kGy. The irradiated leather was washed by water, dried and then physical tested. The results of physical test of leather modified with n-butyl acrylate showed the increasing of tensile strength and elongation, decreasing of water absorption, resistance against the flexing test of 20,000 times, and PH was constant. Organoleptic test showed that the softly of the modified leather was no different with unmodified leather.

  6. A Mechanistic Investigation of Gelation. The Sol-Gel Polymerization of Bridged Silsesquioxane Monomers

    Energy Technology Data Exchange (ETDEWEB)

    SHEA,KENNETH J.; LOY,DOUGLAS A.

    2000-07-14

    The study of a homologous series of silsesquioxane monomers has uncovered striking discontinuities in gelation behavior. An investigation of the chemistry during the early stages of the polymerization has provided a molecular basis for these observations. Monomers containing from one to four carbon atoms exhibit a pronounced tendency to undergo inter or intramolecular cyclization. The cyclic intermediates have been characterized by {sup 29}Si NMR, chemical ionization mass spectrometry and isolation from the reaction solution. These carbosiloxanes are local thermodynamic sinks that produce kinetic bottlenecks in the production of high molecular weight silsesquioxanes. The formation of cyclics results in slowing down or in some cases completely shutting down gelation. An additional finding is that the cyclic structures are incorporated intact into the final xerogel. Since cyclization alters the structure of the building block that eventually makes up the xerogel network, it is expected that this will contribute importantly to the bulk properties of the xerogel as well.

  7. Cobalt-mediated radical polymerization of vinyl monomers: investigation of cobalt-coordination

    OpenAIRE

    2009-01-01

    Controlled Radical Polymerization techniques have been developed to obtain well-defined architectures and to control polymer parameters. Among these systems is Cobalt-Mediated Radical Polymerization (CMRP), which is based on the reversible deactivation of the growing radical chains with a cobalt complex, the cobalt (II) bis(acetylacetonate). The interest of this system is not only due to its ability to control the polymerization of very reactive monomers such as vinyl acetate (VAc) and N-viny...

  8. The Acyl Desaturase CER17 Is Involved in Producing Wax Unsaturated Primary Alcohols and Cutin Monomers.

    Science.gov (United States)

    Yang, Xianpeng; Zhao, Huayan; Kosma, Dylan K; Tomasi, Pernell; Dyer, John M; Li, Rongjun; Liu, Xiulin; Wang, Zhouya; Parsons, Eugene P; Jenks, Matthew A; Lü, Shiyou

    2017-02-01

    We report n-6 monounsaturated primary alcohols (C26:1, C28:1, and C30:1 homologs) in the cuticular waxes of Arabidopsis (Arabidopsis thaliana) inflorescence stem, a class of wax not previously reported in Arabidopsis. The Arabidopsis cer17 mutant was completely deficient in these monounsaturated alcohols, and CER17 was found to encode a predicted ACYL-COENZYME A DESATURASE LIKE4 (ADS4). Studies of the Arabidopsis cer4 mutant and yeast variously expressing CER4 (a predicted fatty acyl-CoA reductase) with CER17/ADS4, demonstrated CER4's principal role in synthesis of these monounsaturated alcohols. Besides unsaturated alcohol deficiency, cer17 mutants exhibited a thickened and irregular cuticle ultrastructure and increased amounts of cutin monomers. Although unsaturated alcohols were absent throughout the cer17 stem, the mutation's effects on cutin monomers and cuticle ultrastructure were much more severe in distal than basal stems, consistent with observations that the CER17/ADS4 transcript was much more abundant in distal than basal stems. Furthermore, distal but not basal stems of a double mutant deficient for both CER17/ADS4 and LONG-CHAIN ACYL-COA SYNTHETASE1 produced even more cutin monomers and a thicker and more disorganized cuticle ultrastructure and higher cuticle permeability than observed for wild type or either mutant parent, indicating a dramatic genetic interaction on conversion of very long chain acyl-CoA precursors. These results provide evidence that CER17/ADS4 performs n-6 desaturation of very long chain acyl-CoAs in both distal and basal stems and has a major function associated with governing cutin monomer amounts primarily in the distal segments of the inflorescence stem.

  9. Chiral separation by (S)-naproxen imprinted monolithic column with mixed functional monomers

    Institute of Scientific and Technical Information of China (English)

    Zhen Ying Li; Zhao Sheng Liu; Qing Wei Zhang; Hong Quan Duan

    2007-01-01

    Molecularly imprinted polymers (MIPs), using (S)-naproxen as template and the combination of butyl methacrylate (BMA) and column was evaluated in HPLC mode. The result showed that the monolithic MIPs with the combination of two monomers produced better chiral resolution of rac-naproxen (Rs = 1.55) and column efficiencies of imprinted molecules (N = 2860 plates/m)than that with pure MAA.

  10. Chemical analysis of monomers in epoxy resins based on bisphenols F and A.

    Science.gov (United States)

    Pontén, A; Zimerson, E; Sörensen, O; Bruze, M

    2004-05-01

    Diglycidyl ether of bisphenol A (DGEBA) is the monomer and most important contact allergen in epoxy resin(s) based on bisphenol A (DGEBA-R). Both thin-layer chromatography (TLC) and high-pressure liquid chromatography (HPLC) methods are available for the analysis of products containing DGEBA-R. With respect to detection and quantification, epoxy resins of the bisphenol F-type, i.e. epoxy resins containing the isomers of diglycidyl ethers of bisphenol F (DGEBF), are not as well investigated as DGEBA-R. The isomers of DGEBF are p,p'-DGEBF, o,p'-DGEBF and o,o'-DGEBF. Both p,p'-DGEBF and o,p'-DGEBF have been shown to be contact allergens in humans, and all 3 isomers are sensitizers in the guinea pig maximization test. We aimed (i). to develop HPLC methods for separation and purification of the individual DGEBF isomers, (ii). to detect and quantify the DGEBF isomers in epoxy resins of the bisphenol F-type and (iii). to evaluate and develop the TLC as a method for the detection of the DGEBF monomers. We found the total content of the DGEBF isomers in the investigated epoxy resins of the bisphenol F-type to vary from 17.0 to 81.7% w/w. Some of them also contained 0.1-2.4% w/w DGEBA. The HPLC method showed a sensitivity that was 2000-20 000x higher than that obtained with the TLC method for the DGEBF monomers. We concluded that the range of the DGEBF isomer content in epoxy resins of the bisphenol F-type is approximately the same as the monomer content in liquid compared to solid DGEBA-R. The relevance of contact allergy to DGEBA-R can remain unrecognized if the suspected product is an epoxy resin of the bisphenol F-type, which is analysed with the TLC method.

  11. Direct Arylation Strategies in the Synthesis of π-Extended Monomers for Organic Polymeric Solar Cells

    OpenAIRE

    Andrea Nitti; Riccardo Po; Gabriele Bianchi; Dario Pasini

    2016-01-01

    π-conjugated macromolecules for organic polymeric solar cells can be rationally engineered at the molecular level in order to tune the optical, electrochemical and solid-state morphology characteristics, and thus to address requirements for the efficient solid state device implementation. The synthetic accessibility of monomers and polymers required for the device is getting increasing attention. Direct arylation reactions for the production of the π-extended scaffolds are gaining importance,...

  12. Papain-Catalyzed Synthesis of Polyglutamate Containing a Nylon Monomer Unit

    OpenAIRE

    Kenjiro Yazawa; Keiji Numata

    2016-01-01

    Peptides have the potential to serve as an alternative for petroleum-based polymers to support a sustainable society. However, they lack thermoplasticity, owing to their strong intermolecular interactions. In contrast, nylon is famous for its thermoplasticity and chemical resistance. Here, we synthesized peptides containing a nylon unit to modify their thermal properties by using papain-catalyzed chemoenzymatic polymerization. We used l-glutamic acid alkyl ester as the amino acid monomer and ...

  13. Controlled Release of Benzocaine from Monomer and Copolymer Carriers in Synthetic Gastro-intestinal Media

    Directory of Open Access Journals (Sweden)

    Houaria Merine

    2014-05-01

    Full Text Available New dosage forms able to control drug release in the gastro-intestinal media have been prepared and investigated in this paper. Two different type of medicinal agent bonding (MA, in our case Benzocaine (Bz, were chosen in order to examine drug release. i MA attached to ethylenic monomer (m,p-vinylbenzaldehyde, condensation reaction. ii The copolymer carrier (Cp is obtained by copolymerizing this monomer. These two carriers were well characterized by microanalysis, FTIR, DSC (Tg and GPC (Ip and the two fraction α and β were calculated from elemental analyses of Cp. The results showed good polydispersity and low average molecular weight. MA linked to an organic product by the azomethine function (C=N, hydrolytically sensitive, allowed controlled release of Bz, from the monomer carrier and from the bending Schiff bases groups. Theoretical and experimental analyses of controlled release of Bz kinetics from monomer and copolymer carriers were conducted for the case of contact with synthetic gastro-intestinal fluids at various pH (1,2; 6,0 and 8,0 at 37°C. The process was found to be controlled by the nature of media (heterogeneous, which involved the preliminary hydrolysis, and the drug (Bz diffusing out of structure of copolymer (Cp to the external aqueous media. The results obtained on the rate of delivery showed a clear difference between pH = 1,2 and pH = 6,0 and 8,0 based on: i The cation of p-aminoniumbenzoic acid (PABAH+ release at pH = 1,2 ii Bz release at pH = 6,0 and 8,0

  14. Ferrocene-Based Monomers, Oligomers and Polymers as Electro-Active Materials

    OpenAIRE

    Al Khalyfeh, Khaled

    2016-01-01

    The present PhD thesis deals with the synthesis and characterization of functionalized ferrocenes with up to four aldehyde and vinyl groups and their usage as monomers to produce novel ferrocene-based oligomers with conjugated backbones via ADMET (acyclic diene metathesis) and HWE (Horner-Wadsworth-Emmons) reaction protocols. In addition, ferrocene-containing polymers (linear, cross-linked and co-polymers) with aliphatic backbones generated by anionic bulk and solution polymerization routes, ...

  15. Effect of trifluoroethylene monomers on molecular conformation of poly (vinylidene fluoride-trifluoroethylene) copolymer

    Institute of Scientific and Technical Information of China (English)

    Li Ji-Chao; Wang Chun-Lei; Zhong Wei-Lie

    2004-01-01

    Hartree-Fock and density functional theory (DFT) methods were employed to study poly (vinylidene fluoridetrifluoroethylene) [P(VDF-TrFE)] molecular chains with different VDF contents. The dependence of dipole moment of P(VDF-TrFE) chains on VDF content obtained from our calculation is in good agreement with the experiment. The TrFE monomer plays an important role in introducing the gauche bond into copolymer chains. A possible mechanism was interpreted.

  16. Hemoglobin-imprinted polymer gel prepared using modified glucosamine as functional monomer

    Institute of Scientific and Technical Information of China (English)

    Hai Li Zhao; Tian Ying Guo; Yong Qing Xia; Mou Dao Song

    2008-01-01

    A new functional glycomonomer was obtained from modified glucosamine.Hemoglobin-imprinted polymer gel was prepared with allyl-bromide modified glucosamine as functional monomer,poly(ethylene-glycol)diaorylate(PEGDA)as cross-linker and ammonium persulfate[(NH4)2S2O8]/sodium hydrogen sulfite(NaHSO3)as initiators in a phosphate buffer.The adsorption capacity and selective adsorption of the molecular imprinting polymer(MIP)were also discussed.

  17. D-polyglutamine amyloid recruits L-polyglutamine monomers and kills cells

    Science.gov (United States)

    Kar, Karunakar; Arduini, Irene; Drombosky, Kenneth W.; van der Wel, Patrick C. A.; Wetzel, Ronald

    2014-01-01

    Polyglutamine (polyQ) amyloid fibrils are observed in disease tissue and have been implicated as toxic agents responsible for neurodegeneration in expanded CAG repeat diseases like Huntington’s disease (HD). Despite intensive efforts, the mechanism of amyloid toxicity remains unknown. As a novel approach to probing polyQ toxicity, we investigate here how some cellular and physical properties of polyQ amyloid vary with the chirality of the glutamine residues in the polyQ. We challenged PC12 cells with small amyloid fibrils composed of either L- or D-polyQ peptides and found that D-fibrils are as cytotoxic as L-fibrils. We also found using fluorescence microscopy that both aggregates effectively seed the aggregation of cell-produced L-polyQ proteins, suggesting a surprising lack of stereochemical restriction in seeded elongation of polyQ amyloid. To investigate this effect further, we studied chemically synthesized D- and L-polyQ in vitro. We found that, as expected, D-polyQ monomers are not recognized by proteins that recognize L-polyQ monomers. However, amyloid fibrils prepared from D-polyQ peptides can efficiently seed the aggregation of L-polyQ monomers in vitro, and vice versa. This result is consistent with our cell results on polyQ recruitment, but is inconsistent with previous literature reports on the chiral specificity of amyloid seeding. This chiral cross-seeding can be rationalized by a model for seeded elongation featuring a “rippled β-sheet” interface between seed fibril and docked monomers of opposite chirality. The lack of chiral discrimination in polyQ amyloid cytotoxicity is consistent with several toxicity mechanisms, including recruitment of cellular polyQ proteins. PMID:24291210

  18. Vegetable oil-derived epoxy monomers and polymer blends: A comparative study with review

    OpenAIRE

    T. P. Schuman; Wang, R.

    2013-01-01

    Glycidyl esters of epoxidized fatty acids derived from soybean oil (EGS) and linseed oil (EGL) have been synthesized to have higher oxirane content, more reactivity and lower viscosity than epoxidized soybean oil (ESO) or epoxidized linseed oil (ELO). The EGS and ESO, for comparison, were used neat and in blends with diglycidyl ether of bisphenol A (DGEBA). Thermosetting resins were fabricated with the epoxy monomers and either BF3 catalyst or anhydride. The curing behaviors, glass transition...

  19. Enhanced lignin monomer production caused by cinnamic Acid and its hydroxylated derivatives inhibits soybean root growth.

    Directory of Open Access Journals (Sweden)

    Rogério Barbosa Lima

    Full Text Available Cinnamic acid and its hydroxylated derivatives (p-coumaric, caffeic, ferulic and sinapic acids are known allelochemicals that affect the seed germination and root growth of many plant species. Recent studies have indicated that the reduction of root growth by these allelochemicals is associated with premature cell wall lignification. We hypothesized that an influx of these compounds into the phenylpropanoid pathway increases the lignin monomer content and reduces the root growth. To confirm this hypothesis, we evaluated the effects of cinnamic, p-coumaric, caffeic, ferulic and sinapic acids on soybean root growth, lignin and the composition of p-hydroxyphenyl (H, guaiacyl (G and syringyl (S monomers. To this end, three-day-old seedlings were cultivated in nutrient solution with or without allelochemical (or selective enzymatic inhibitors of the phenylpropanoid pathway in a growth chamber for 24 h. In general, the results showed that 1 cinnamic, p-coumaric, caffeic and ferulic acids reduced root growth and increased lignin content; 2 cinnamic and p-coumaric acids increased p-hydroxyphenyl (H monomer content, whereas p-coumaric, caffeic and ferulic acids increased guaiacyl (G content, and sinapic acid increased sinapyl (S content; 3 when applied in conjunction with piperonylic acid (PIP, an inhibitor of the cinnamate 4-hydroxylase, C4H, cinnamic acid reduced H, G and S contents; and 4 when applied in conjunction with 3,4-(methylenedioxycinnamic acid (MDCA, an inhibitor of the 4-coumarate:CoA ligase, 4CL, p-coumaric acid reduced H, G and S contents, whereas caffeic, ferulic and sinapic acids reduced G and S contents. These results confirm our hypothesis that exogenously applied allelochemicals are channeled into the phenylpropanoid pathway causing excessive production of lignin and its main monomers. By consequence, an enhanced stiffening of the cell wall restricts soybean root growth.

  20. HEMA inhibits interfacial nano-layering of the functional monomer MDP.

    Science.gov (United States)

    Yoshida, Y; Yoshihara, K; Hayakawa, S; Nagaoka, N; Okihara, T; Matsumoto, T; Minagi, S; Osaka, A; Van Landuyt, K; Van Meerbeek, B

    2012-11-01

    Previous research showed that the functional monomer 10-methacryloxydecyl dihydrogen phosphate (MDP) ionically bonds to hydroxyapatite (HAp) and forms a nano-layered structure at the interface with HAp-based substrates. Such hydrophobic nano-layering is considered to contribute to the long-term durability of the bond to tooth tissue. However, dental adhesives are complex mixtures usually containing different monomers. This study investigated the effect of the monomer 2-hydroxyethylmethacrylate (HEMA) on the chemical interaction of MDP with HAp by x-ray diffraction (XRD), nuclear magnetic resonance (NMR), and quartz crystal microbalance (QCM). We examined the chemical interaction of 5 experimental MDP solutions with increasing concentrations of HEMA. XRD revealed that addition of HEMA inhibits nano-layering at the interface, while NMR confirmed that MDP remained adsorbed onto the HAp surface. QCM confirmed this adsorption of MDP to HAp, as well as revealed that the demineralization rate of HAp by MDP was reduced by HEMA. It was concluded that even though the adsorption of MDP to HAp was not hindered, addition of HEMA inhibited interfacial nano-layering. Potential consequences with regard to bond durability necessitate further research.

  1. Chemical graft polymerization of sulfobetaine monomer on polyurethane surface for reduction in platelet adhesion.

    Science.gov (United States)

    Yuan, Jiang; Chen, Li; Jiang, Xuefeng; Shen, Jian; Lin, Sicong

    2004-11-25

    Surface modification is an effective way to improve the hemocompatibility and remain bulk properties of biomaterials. Recently, polymer tailored with zwitterions was found having good blood compatibility. In this study, the zwitterionic monomer of sulfobetaine was graft polymerized onto polyurethane (PU) surface in a three-step heterogenous system through the vinyl bonds of acrylic acid (AA) or hydroxyethyl methacrylate (HEMA), which was immobilized with hexamethylene diisocyanate (HDI) beforehand. First, PU was activated with isocyanate groups using HDI as coupling agent. Second, AA or HEMA was introduced through reaction of AA or HEMA with NCO groups bonded on PU surface. Last, zwitterionic monomer of sulfobetain was graft polymerized with vinyl group of AA or HEMA using AIBN as polymerization initiator. The reaction process was monitored with ATR-IR spectra and XPS spectra. Variation of graft yield with temperature and monomer feed concentration was investigated and feasible conditions were optimized. The wettability of films was investigated by water contact angle measurement and water absorbance. Platelet adhesion experiment was conducted as a preliminary test to confirm the improved blood compatibility of PU. The number of platelets adhering to PU decreased greatly comparing with the originals after 1 and 3 h of contact with human plate-rich plasma (PRP).

  2. Poly-amido-saccharides: synthesis via anionic polymerization of a β-lactam sugar monomer.

    Science.gov (United States)

    Dane, Eric L; Grinstaff, Mark W

    2012-10-01

    Enantiopure poly-amido-saccharides (PASs) with a defined molecular weight and narrow dispersity are synthesized using an anionic ring-opening polymerization of a β-lactam sugar monomer. The PASs have a previously unreported main chain structure that is composed of pyranose rings linked through the 1- and 2-positions by an amide with α-stereochemistry. The monomer is synthesized in one-step from benzyl-protected D-glucal and polymerized using mild reaction conditions to give degrees of polymerization ranging from 25 to >120 in high yield. Computational modeling reveals how the monomer's structure and steric bulk affect the thermodynamics and kinetics of polymerization. Protected and deprotected polymers and model compounds are characterized using a variety of methods (NMR, GPC, IR, DLS, etc.). On the basis of circular dichroism, the deprotected polymer possesses a regular secondary structure in aqueous solution, which agrees favorably with the prediction of a helical structure using molecular modeling. Furthermore, we provide evidence suggesting that the polymers bind the lectin concanavalin A at the same site as natural carbohydrates, showing the potential of these polymers to mimic natural polysaccharides. PASs offer the advantages associated with synthetic polymers, such as greater control over structure and derivitization. At the same time, they preserve many of the structural features of natural polysaccharides, such as a stereochemically regular, rigid pyranose backbone, that make natural carbohydrate polymers important materials both for their unique properties and useful applications.

  3. Molecularly imprinted microspheres prepared by precipitation polymerization at high monomer concentrations

    Directory of Open Access Journals (Sweden)

    Renkecz Tibor

    2014-01-01

    Full Text Available Highly crosslinked polymer microparticles have been prepared by precipitation polymerization using high monomer loadings (≥25 v/v % which generally would lead to bulk monoliths. The microparticle format was achieved by the use of non-solvating diluents either alone or in combination with co-solvents. Two distinct morphologies were observed. Monodisperse smooth microspheres were obtained using a thermodynamically good co-solvent whereas segmented irregular particles were formed with poorer co-solvents. It has been found that during polymerization the forming polymer particles were enriched in the co-solvent and this effect was more pronounced when good co-solvents were used. The type of functional monomer, crosslinker and co-solvent, and the non-solvent/co-solvent ratio were identified as influential parameters on the microparticle morphology. With the proposed methodology molecularly imprinted microparticles have been prepared successfully for three different templates, naproxen, diclofenac and toltrazuril using various functional monomers, crosslinkers and polymerization solvent mixtures.

  4. Vinyl monomers-induced synthesis of polyvinyl alcohol-stabilized selenium nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Shah, Chetan P.; Singh, Krishan K. [Radiation and Photochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India); Kumar, Manmohan, E-mail: manmoku@barc.gov.in [Radiation and Photochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India); Bajaj, Parma N. [Radiation and Photochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India)

    2010-01-15

    A simple wet chemical method has been developed to synthesize selenium nanoparticles (size 100-200 nm), by reaction of sodium selenosulphate precursor with different vinyl monomers, such as acrylamide, N,N'-dimethylene bis acrylamide, methyl methacrylate, sodium acrylate, etc., in aqueous medium, under ambient conditions. Polyvinyl alcohol has been used to stabilize the selenium nanoparticles. Average size of the synthesized selenium nanoparticles can be controlled by adjusting concentration of both the precursors and the stabilizer. Rate of the reaction as well as size of the resultant selenium nanoparticles have been correlated with the functional groups of the different monomers. UV-vis optical absorption spectroscopy, X-ray diffraction, energy dispersive X-rays, differential scanning calorimetry, atomic force microscopy, scanning electron microscopy and transmission electron microscopy techniques have been employed to characterize the synthesized selenium nanoparticles. Gas chromatographic analysis of the reaction mixture established the non-catalytic role of the vinyl monomers, which were found to be consumed during the course of the reaction.

  5. A new label dosimetry system based on pentacosa-diynoic acid monomer for low dose applications

    Energy Technology Data Exchange (ETDEWEB)

    Abdel-Fattah, A.A.; Abdel-Rehim, F. [National Center for Radiation Research and Technology, Atomic Energy Authority, P.O. Box 8029, Nasr City, Cairo (Egypt); Soliman, Y.S., E-mail: yasser_shabaan@hotmail.com [National Center for Radiation Research and Technology, Atomic Energy Authority, P.O. Box 8029, Nasr City, Cairo (Egypt)

    2012-01-15

    The dosimetric characteristics of {gamma}-radiation sensitive labels based on polyvinyl butyral (PVB) and a conjugated diacetylene monomer, 10,12-pentacosa-diynoic acid (PCDA) have been investigated using reflectance colorimeter. Two types of labels (colourless and yellow) based on PCDA monomer were prepared using an Automatic Film Applicator System. Upon {gamma}-ray exposure, the colourless label turns progressively blue, while the yellow colour label turns to green then to dark blue. The colour intensity of the labels is proportional to the radiation absorbed dose. The useful dose range was 15 Gy-2 kGy depending on PCDA monomer concentration. The expanded uncertainty of dose measurement of the colourless label was 6.06 (2{sigma}). - Highlights: > Using 10,12-pentacosa-diynoic acid (PCDA) in preparation of label dosimeter. > PCDA polymerises upon {gamma}-rays exposure producing a blue coloured polymer. > Useful dose range is 15 Gy to 2 kGy depending on concentration of PCDA. > Overall uncertainty of label dosimeter was 6.06 at 2{sigma}.

  6. Formation of monomer residues in PS, PC, PA-6 and PVC upon {gamma}-irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Young Park, Gun [Graduate School of Biotechnology, Korea University, 1.5-Ka, Anam-Dong, Seongbuk-Ku, Seoul 136-701 (Korea, Republic of); Yong Cho, Seung [Functional Food Research Center, College of Life Sciences, Korea University, 1.5-Ka, Anam-Dong, Seongbuk-Ku, Seoul 136-701 (Korea, Republic of); Hoon Jeon, Dae [Graduate School of Biotechnology, Korea University, 1.5-Ka, Anam-Dong, Seongbuk-Ku, Seoul 136-701 (Korea, Republic of); Food Packaging Division, Korea Food and Drug Administration (KFDA), 5 Nokbun-Dong, Eunpyung-Ku, Seoul 122-704 (Korea, Republic of); Shin Kwak, In [Food Packaging Division, Korea Food and Drug Administration (KFDA), 5 Nokbun-Dong, Eunpyung-Ku, Seoul 122-704 (Korea, Republic of); Ho Lee, Kwang [Food Packaging Division, Korea Food and Drug Administration (KFDA), 5 Nokbun-Dong, Eunpyung-Ku, Seoul 122-704 (Korea, Republic of); Park, H.J. [Graduate School of Biotechnology, Korea University, 1.5-Ka, Anam-Dong, Seongbuk-Ku, Seoul 136-701 (Korea, Republic of) and Department of Packaging Science, Clemson University, Clemson, South Carolina 29634-0370 (United States)]. E-mail: hjpark@korea.ac.kr

    2006-09-15

    Food packaging polymers, polystyrene (PS), polycarbonate (PC), polyamide-6 (PA-6), and polyvinylchloride (PVC), were irradiated with dose in the range 5-200 kGy. The quantities of corresponding monomer residues (styrene monomer, bisphenol-A, {epsilon}-caprolactam, vinyl chloride) released from target materials were analyzed using a SIM mode of GC/MSD. Styrene monomer in PS showed a slight increase from 740 to 777 ppm at 5-30 kGy and then decreased as the dose increased from 30 to 200 kGy. Bisphenol-A in PC was dose independent at the low doses, 5, 10 and 30 kGy, but its level increased from 173 to 473 ppm at 30 kGy and thereafter remained unchanged through 200 kGy. {epsilon}-Caprolactam in PA-6 was also dose independent, in the range of 5-200 kGy, but its level (122-164 ppm) was found to be higher than those (71 ppm) of non-irradiated sample. As for PVC, the quantity of vinyl chloride tended to increase from 8 to 18 ppm at 5-200 kGy.

  7. Permeability of different types of medical protective gloves to acrylic monomers.

    Science.gov (United States)

    Lönnroth, Emma-Christin; Wellendorf, Hanne; Ruyter, Eystein

    2003-10-01

    Dental personnel and orthopedic surgeons are at risk when manually handling products containing methyl methacrylate (MMA). Dental products may also contain cross-linking agents such as ethylene glycol dimethacrylate (EGDMA) or 1,4-butanediol dimethacrylate (1,4-BDMA). Skin contact with monomers can cause hand eczema, and the protection given by gloves manufactured from different types of material is not well known. The aim of this study was to determine the breakthrough time (BTT, min) as a measure of protection (according to the EU standard EN-374-3) for a mixture consisting of MMA, EGDMA and 1,4-BDMA. Fifteen different gloves representing natural rubber latex material, synthetic rubber material (e.g. nitrile rubbers), and synthetic polymer material were tested. The smallest monomer MMA permeated within 3 min through all glove materials. A polyethylene examination glove provided the longest protection period to EGDMA and 1, 4-BDMA (> 120 min and 25.0 min), followed by the surgical glove Tactylon (6.0 min and 8.7 min) and the nitrile glove Nitra Touch (5.0 min and 8.7 min). This study showed that the breakthrough time (based on permeation rate) cannot be regarded as a 'safe limit'. When the permeation rate is low, monomers may have permeated before BTT can be determined. Using double gloves with a synthetic rubber inner glove and a natural rubber outer glove provided longer protection when the inner glove was rinsed in water before placing the outer glove on top.

  8. Energy landscapes of the monomer and dimer of the Alzheimer's peptide A β (1 -28 )

    Science.gov (United States)

    Dong, Xiao; Chen, Wei; Mousseau, Normand; Derreumaux, Philippe

    2008-03-01

    The cytoxicity of Alzheimer's disease has been linked to the self-assembly of the 40 /42 amino acid of the amyloid-β (A β ) peptide into oligomers. To understand the assembly process, it is important to characterize the very first steps of aggregation at an atomic level of detail. Here, we focus on the N-terminal fragment 1-28, known to form fibrils in vitro. Circular dichroism and NMR experiments indicate that the monomer of A β (1 -28 ) is α -helical in a membranelike environment and random coil in aqueous solution. Using the activation-relaxation technique coupled with the OPEP coarse grained force field, we determine the structures of the monomer and of the dimer of A β (1 -28 ) . In agreement with experiments, we find that the monomer is predominantly random coil in character, but displays a non-negligible β -strand probability in the N-terminal region. Dimerization impacts the structure of each chain and leads to an ensemble of intertwined conformations with little β -strand content in the region Leu17-Ala21. All these structural characteristics are inconsistent with the amyloid fibril structure and indicate that the dimer has to undergo significant rearrangement en route to fibril formation.

  9. Energy landscapes of the monomer and dimer of the Alzheimer's peptide Abeta(1-28).

    Science.gov (United States)

    Dong, Xiao; Chen, Wei; Mousseau, Normand; Derreumaux, Philippe

    2008-03-28

    The cytotoxicity of Alzheimer's disease has been linked to the self-assembly of the 4042 amino acid of the amyloid-beta (Abeta) peptide into oligomers. To understand the assembly process, it is important to characterize the very first steps of aggregation at an atomic level of detail. Here, we focus on the N-terminal fragment 1-28, known to form fibrils in vitro. Circular dichroism and NMR experiments indicate that the monomer of Abeta(1-28) is alpha-helical in a membranelike environment and random coil in aqueous solution. Using the activation-relaxation technique coupled with the OPEP coarse grained force field, we determine the structures of the monomer and of the dimer of Abeta(1-28). In agreement with experiments, we find that the monomer is predominantly random coil in character, but displays a non-negligible beta-strand probability in the N-terminal region. Dimerization impacts the structure of each chain and leads to an ensemble of intertwined conformations with little beta-strand content in the region Leu17-Ala21. All these structural characteristics are inconsistent with the amyloid fibril structure and indicate that the dimer has to undergo significant rearrangement en route to fibril formation.

  10. Two Functionally Distinct Sources of Actin Monomers Supply the Leading Edge of Lamellipodia

    Science.gov (United States)

    Vitriol, Eric A.; McMillen, Laura M.; Kapustina, Maryna; Gomez, Shawn M.; Vavylonis, Dimitrios; Zheng, James Q.

    2015-01-01

    Summary Lamellipodia, the sheet-like protrusions of motile cells, consist of networks of actin filaments (F-actin) regulated by the ordered assembly from and disassembly into actin monomers (G-actin). Traditionally, G-actin is thought to exist as a homogeneous pool. Here, we show that there are two functionally and molecularly distinct sources of G-actin that supply lamellipodial actin networks. G-actin originating from the cytosolic pool requires the monomer binding protein thymosin β4 (Tβ4) for optimal leading edge localization, is targeted to formins, and is responsible for creating an elevated G/F-actin ratio that promotes membrane protrusion. The second source of G-actin comes from recycled lamellipodia F-actin. Recycling occurs independently of Tβ4 and appears to regulate lamellipodia homeostasis. Tβ4-bound G-actin specifically localizes to the leading edge because it doesn’t interact with Arp2/3-mediated polymerization sites found throughout the lamellipodia. These findings demonstrate that actin networks can be constructed from multiple sources of monomers with discrete spatiotemporal functions. PMID:25865895

  11. Sequence Analysis of Trimer Isomers Formed by Montmorillonite Catalysis in the Reaction of Binary Monomer Mixtures

    Science.gov (United States)

    Ertem, Gözen; Hazen, Robert M.; Dworkin, Jason P.

    2007-10-01

    Oligonucleotides are structurally similar to short RNA strands. Therefore, their formation via non-enzymatic reactions is highly relevant to Gilbert's RNA world scenario (1986) and the origin of life. In laboratory synthesis of oligonucleotides from monomers, it is necessary to remove the water molecules from the reaction medium to shift the equilibrium in favor of oligonucleotide formation, which would have been impossible for reactions that took place in dilute solutions on the early Earth. Model studies designed to address this problem demonstrate that montmorillonite, a phyllosilicate common on Earth and identified on Mars, efficiently catalyzes phosphodiester-bond formation between activated mononucleotides in dilute solutions and produces RNA-like oligomers. The purpose of this study was to examine the sequences and regiospecificity of trimer isomers formed in the reaction of 5'-phosphorimidazolides of adenosine and uridine. Results demonstrated that regiospecificity and sequence specificity observed in the dimer fractions are conserved in their elongation products. With regard to regiospecificity, 61% of the linkages were found to be RNA-like 3',5'-phosphodiester bonds. With regard to sequence specificity, we found that 88% of the linear trimers were hetero-isomers with 61% A-monomer and 39% U-monomer incorporation. These results lend support to Bernal's hypothesis that minerals may have played a significant role in the chemical processes that led to the origin of life by catalyzing the formation of phosphodiester bonds in RNA-like oligomers.

  12. Synthesis and characterization of copolymers from hindered amines and vinyl monomers

    Directory of Open Access Journals (Sweden)

    Marcelo Aparecido Chinelatto

    2014-01-01

    Full Text Available New copolymers from hindered amines and vinyl monomers were synthesized by radical chain polymerization. To obtain polymeric HALS, acrylamide-(1ATP and acrylate-(4ATP monomers, derivatives from 2,2,6,6-tetramethylpiperidine and 2,2,6,6-tetramethyl-4-piperidinol were synthesized. The radical chain polymerization of 1ATP with styrene (Sty using 1-butanethiol (BTN resulted in a copolymer with 95 units of Sty and 15 units of 1ATP. The radical chain polymerization of 1ATP and vinyl acetate (VAc has produced only 1ATP homopolymer. In the chain polymerization of 4ATP with Sty or VAc, the hydrogen atom bonded to the nitrogen of 4ATP is labile enough to originate another radical at this site. The steric hindrance imposed by methyl groups on this bonding site hampers its reaction with other propagating species and the formation of a copolymer or network structure will be dependent on the size of the pendent group in the vinyl monomer.

  13. Self-assembly of actin monomers into long filaments: Brownian Dynamics simulations

    DEFF Research Database (Denmark)

    Shillcock, Julian C.

    2009-01-01

    /detachment events. When a single filament is allowed to grow in a bath of constant concentration of free ADP-actin monomers, its growth rate increases linearly with the free monomer concentration in quantitative agreement with in vitro experiments. Theresults also show that the waiting time is governed by exponential......Brownian dynamics simulations are used to study the dynamical process of self-assembly of actin monomers into long filaments containing up to 1000 actin protomers. In order to overcome the large separation of time scales between the diffusive motion of the freemonomers and the relatively slow...... states corresponding to a bound adenosine triphosphate (ATP), adenosine diphosphate with inorganic phosphate (ADP/P), and ADP molecule. The simplest situation that has been studied experimentally is provided by the polymerization of ADP-actin, for which all protomers are identical. This case is used...

  14. Non-conjugated small molecule FRET for differentiating monomers from higher molecular weight amyloid beta species.

    Directory of Open Access Journals (Sweden)

    Chongzhao Ran

    Full Text Available BACKGROUND: Systematic differentiation of amyloid (Aβ species could be important for diagnosis of Alzheimer's disease (AD. In spite of significant progress, controversies remain regarding which species are the primary contributors to the AD pathology, and which species could be used as the best biomarkers for its diagnosis. These controversies are partially caused by the lack of reliable methods to differentiate the complicated subtypes of Aβ species. Particularly, differentiation of Aβ monomers from toxic higher molecular weight species (HrMW would be beneficial for drug screening, diagnosis, and molecular mechanism studies. However, fast and cheap methods for these specific aims are still lacking. PRINCIPAL FINDINGS: We demonstrated the feasibility of a non-conjugated FRET (Förster resonance energy transfer technique that utilized amyloid beta (Aβ species as intrinsic platforms for the FRET pair assembly. Mixing two structurally similar curcumin derivatives that served as the small molecule FRET pair with Aβ40 aggregates resulted in a FRET signal, while no signal was detected when using Aβ40 monomer solution. Lastly, this FRET technique enabled us to quantify the concentrations of Aβ monomers and high molecular weight species in solution. SIGNIFICANCE: We believe that this FRET technique could potentially be used as a tool for screening for inhibitors of Aβ aggregation. We also suggest that this concept could be generalized to other misfolded proteins/peptides implicated in various pathologies including amyloid in diabetes, prion in bovine spongiform encephalopathy, tau protein in AD, and α-synuclein in Parkinson disease.

  15. Wire and extended ladder model predict THz oscillations in DNA monomers, dimers and trimers

    CERN Document Server

    Lambropoulos, K; Morphis, A; Tassi, M; Lopp, R; Georgiadis, G; Theodorakou, M; Chatzieleftheriou, M; Simserides, C

    2016-01-01

    We call \\textit{monomer} a B-DNA base pair and study, analytically and numerically, electron or hole oscillations in \\textit{monomers}, \\textit{dimers} and \\textit{trimers}. We employ two Tight Binding (TB) approaches: (I) at the base-pair level, using the on-site energies of the base pairs and the hopping parameters between successive base pairs i.e. \\textit{a wire model}, and (II) at the single-base level, using the on-site energies of the bases and the hopping parameters between neighbouring bases, specifically between (a) two successive bases in the same strand, (b) complementary bases that define a base pair, and (c) diagonally located bases of successive base pairs, i.e. \\textit{an extended ladder model} since it also includes the diagonal hoppings (c). For \\textit{monomers}, with TB II, we predict periodic carrier oscillations with frequency $f \\approx$ 50-550 THz. For \\textit{dimers}, with TB I, we predict periodic carrier oscillations with $f \\approx$ 0.25-100 THz. For \\textit{trimers made of identic...

  16. Hydrophobic Coatings on Cotton Obtained by in Situ Plasma Polymerization of a Fluorinated Monomer in Ethanol Solutions.

    Science.gov (United States)

    Molina, Ricardo; Teixidó, Josep Maria; Kan, Chi-Wai; Jovančić, Petar

    2017-02-15

    Plasma polymerization using hydrophobic monomers in the gas phase is a well-known technology to generate hydrophobic coatings. However, synthesis of functional hydrophobic coatings using plasma technology in liquids has not yet been accomplished. This work is consequently focused on polymerization of a liquid fluorinated monomer on cotton fabric initiated by atmospheric plasma in a dielectric barrier discharge configuration. Functional hydrophobic coatings on cotton were successfully achieved using in situ atmospheric plasma-initiated polymerization of fluorinated monomer dissolved in ethanol. Gravimetric measurements reveal that the amount of polymer deposited on cotton substrates can be modulated with the concentration of monomer in ethanol solution, and cross-linking reactions occur during plasma polymerization of a fluorinated monomer even without the presence of a cross-linking agent. FTIR and XPS analysis were used to study the chemical composition of hydrophobic coatings and to get insights into the physicochemical processes involved in plasma treatment. SEM analysis reveals that at high monomer concentration, coatings possess a three-dimensional pattern with a characteristic interconnected porous network structure. EDX analysis reveals that plasma polymerization of fluorinated monomers takes place preferentially at the surface of cotton fabric and negligible polymerization takes place inside the cotton fabric. Wetting time measurements confirm the hydrophobicity of cotton coatings obtained although equilibrium moisture content was slightly decreased. Additionally, the abrasion behavior and resistance to washing of plasma-coated cotton has been evaluated.

  17. A Simple and Rapid Method for Quality Control of Major Histocompatibility Complex-Peptide Monomers by Flow Cytometry.

    Science.gov (United States)

    Chandran, P Anoop; Heidu, Sonja; Zelba, Henning; Schmid-Horch, Barbara; Rammensee, Hans-Georg; Pascolo, Steve; Gouttefangeas, Cécile

    2017-01-01

    Major histocompatibility complex (MHC) multimers are essential tools in T cell immunomonitoring, which are employed both in basic and clinical research, as well as for assessing clinical samples during therapy. The generation of MHC monomers loaded with synthetic peptides is an elaborate and time-consuming process. It would be beneficial to assess the quality of these monomers prior to downstream applications. In this technical note, we describe a novel flow cytometry-based, cell-free, quick, and robust assay to check the quality of MHC monomers directly after refolding or after long-term storage.

  18. A Simple and Rapid Method for Quality Control of Major Histocompatibility Complex–Peptide Monomers by Flow Cytometry

    Science.gov (United States)

    Chandran, P. Anoop; Heidu, Sonja; Zelba, Henning; Schmid-Horch, Barbara; Rammensee, Hans-Georg; Pascolo, Steve; Gouttefangeas, Cécile

    2017-01-01

    Major histocompatibility complex (MHC) multimers are essential tools in T cell immunomonitoring, which are employed both in basic and clinical research, as well as for assessing clinical samples during therapy. The generation of MHC monomers loaded with synthetic peptides is an elaborate and time-consuming process. It would be beneficial to assess the quality of these monomers prior to downstream applications. In this technical note, we describe a novel flow cytometry-based, cell-free, quick, and robust assay to check the quality of MHC monomers directly after refolding or after long-term storage. PMID:28228758

  19. Concomitant contact allergy to formaldehyde and methacrylic monomers in students of dental medicine and dental patients

    Directory of Open Access Journals (Sweden)

    Maya Lyapina

    2014-10-01

    Full Text Available Objectives: A multitude of acrylic monomers is used in dentistry. Formaldehyde is a ubiquitous chemical agent, which is an ingredient of some dental materials and may be released from methacrylate-based composites. The purpose of the study is to evaluate the incidence and the risk of cross-sensitization to some methacrylic monomers (methylmethacrylate – MMA, triethyleneglycol dimethacrylate – TEGDMA, ethyleneglycol dimethacrylate – EGDMA, 2,2-bis-[4-(2-hydroxy-3-metha­crylo-xypropoxyphenyl]-propane – Bis-GMA, 2-hydroxy-ethyl methacrylate 2-HEMA, and tetrahydrofurfuryl methacry­late and formaldehyde in students of dentistry, dental professionals and dental patients. Material and Methods: A total of 139 participants were included in the study, i.e., occupationally exposed dental professionals, students of the 3rd, 4th and 6th year of dental medicine, and occupationally unexposed dental patients. They were patch-tested with methacrylic monomers and formaldehyde. The results were subjected to statistical analysis (p < 0.05. Results: From the allergic to formaldehyde students of the 3rd and 4th year of dental medicine, 46.2% were also sensitized to MMA. Among the group of patients, the incidence of cross-sensitization to formaldehyde and methacrylic monomers was as follows: to TEGDMA – 20.6%, to ethyleneglycol dimethacrylate – 20.7%, to 2-HEMA – 20.7% and to tetrahydrofurfuryl methacrylate – 24.1%. Contact allergy to MMA was diagnosed among 22.7%, and to TEGDMA – among 27.1% of the students of the 3rd and 4th year of dental medicine. In the group of occupationally unexposed dental patients the prevalence of contact allergy to ethyleneglycol dimethacrylate was 20.7%, to Bis-GMA – 27.6%, to 2-HEMA – 44.9% and to tetrahydrofurfuryl methacrylate – 38.0%. Conclusions: The students of the 3rd and 4th year of dental medicine could be outlined as a group at risk of sensitization to MMA and TEGDMA and of cross-sensitization to MMA

  20. Anti-inflammatory peptide regulates the supply of heat shock protein 70 monomers: implications for aging and age-related disease.

    Science.gov (United States)

    Cunningham, Timothy J; Greenstein, Jeffrey I; Loewenstern, Joshua; Degermentzidis, Elias; Yao, Lihua

    2015-04-01

    Reducing the levels of toxic protein aggregates has become a focus of therapy for disorders like Alzheimer's and Parkinson's diseases, as well as for the general deterioration of cells and tissues during aging. One approach has been an attempt to influence the production or activity of a class of reparative chaperones called heat shock proteins (HSPs), of which HSP70 is a promising candidate. Manipulation of HSP70 expression results in disposal of misfolded protein aggregates that accumulate in aging and disease models. Recently, HSP70 has been shown to bind specifically to an amino-terminal sequence of a human diffusible survival evasion peptide (DSEP), dermcidin. This sequence includes CHEC-9, an orally available anti-inflammatory and cell survival peptide. In the present study, we found that the CHEC-9 peptide also binds HSP70 in the cytosol of the cerebral cortex after oral delivery in normal rats. Western analysis of non-heat-denatured, unreduced samples suggested that peptide treatment increased the level of active HSP70 monomers from the pool of chaperone oligomers, a process that may be stimulated by potentiation of the chaperone's adenosine triphosphatase (ATPase). In these samples, a small but consistent gel shift was observed for glyceraldehyde 3-phosphate dehydrogenase (GAPDH), a multifunctional protein whose aggregation is influenced by HSP70. CHEC-9 treatment of an in vitro model of α-synuclein aggregation also results in HSP70-dependent dissolution of these aggregates. HSP70 oligomer-monomer equilibrium and its potential to control protein aggregate disease warrant increased experimental attention, especially if a peptide fragment of an endogenous human protein can influence the process.

  1. Novel Pb2+ ion imprinted polymers based on ionic interaction via synergy of dual functional monomers for selective solid-phase extraction of Pb2+ in water samples.

    Science.gov (United States)

    Cai, Xiaoqiang; Li, Jinhua; Zhang, Zhong; Yang, Fangfang; Dong, Ruichen; Chen, Lingxin

    2014-01-08

    A novel kind of Pb(2+) ion imprinted polymers (IIPs) was prepared based on ionic interactions via the synergy of dual functional monomers of methacrylic acid and vinyl pyridine for selective solid-phase extraction (SPE) of Pb(2+) in water samples. Suspension polymerization was employed for the formation of template Pb(2+)/monomer complex by self-assembly in the presence of ethylene glycol dimethacrylate cross-linker. The resulted Pb(2+) IIPs showed fast kinetics, high binding capacity, and the adsorption processes obeyed intraparticle diffusion kinetics and Langmuir isotherm models. The IIPs displayed excellent selectivity toward Pb(2+) over other metal ions such as Cu(2+), Cd(2+), Zn(2+), and Mn(2+) with selective coefficients above 30, as well as high anti-interference ability for Pb(2+) confronting with common coexisting various ions. Through 10 adsorption-desorption cycles, the reusable IIPs exhibited a good recoverability with the standard error within 5%. These features suggested the IIPs were ideal candidates for extraction and removal of Pb(2+) ions. Consequently, the IIPs were utilized as SPE sorbents and related parameters were optimized. An excellent linearity was presented in the range of 0.2-50 μg L(-1) (R(2) = 0.9998), as well as the limits of detection and quantification were achieved of 0.06 and 0.19 μg L(-1), respectively. A good repeatability was obtained with the relative standard deviation of 2.8%. Furthermore, real water samples were successfully analyzed and satisfactory recoveries varying from 95.5 to 104.6% were attained. The IIPs-SPE demonstrated potential application perspectives for rapid and high-effective cleanup and enrichment of trace Pb(2+) ions in complicated matrices.

  2. Dimer monomer transition and dimer re-formation play important role for ATM cellular function during DNA repair.

    Science.gov (United States)

    Du, Fengxia; Zhang, Minjie; Li, Xiaohua; Yang, Caiyun; Meng, Hao; Wang, Dong; Chang, Shuang; Xu, Ye; Price, Brendan; Sun, Yingli

    2014-10-03

    The ATM protein kinase, is a serine/threonine protein kinase that is recruited and activated by DNA double-strand breaks, mediates responses to ionizing radiation in mammalian cells. Here we show that ATM is held inactive in unirradiated cells as a dimer and phosphorylates the opposite strand of the dimer in response to DNA damage. Cellular irradiation induces rapid intermolecular autophosphorylation of serine 1981 that causes dimer dissociation and initiates cellular ATM kinase activity. ATM cannot phosphorylate the substrates when it could not undergo dimer monomer transition. After DNA repair, the active monomer will undergo dephosphorylation to form dimer again and dephosphorylation is critical for dimer re-formation. Our work reveals novel function of ATM dimer monomer transition and explains why ATM dimer monomer transition plays such important role for ATM cellular activity during DNA repair.

  3. Influence of Monomer Concentration on the Morphologies and Electrochemical Properties of PEDOT, PANI, and PPy Prepared from Aqueous Solution

    Directory of Open Access Journals (Sweden)

    Shalini Kulandaivalu

    2016-01-01

    Full Text Available Poly(3,4-ethylenedioxyhiophene (PEDOT, polyaniline (PANI, and polypyrrole (PPy were prepared on indium tin oxide (ITO substrate via potentiostatic from aqueous solutions containing monomer and lithium perchlorate. The concentration of monomers was varied between 1 and 10 mM. The effects of monomer concentration on the polymers formation were investigated and compared by using Fourier transform infrared spectroscopy (FTIR, Raman spectroscopy, scanning electron microscopy (SEM, cyclic voltammetry (CV, and electrochemical impedance spectroscopy (EIS measurements. FTIR and Raman spectra showed no changes in the peaks upon the increment of the concentration. Based on the SEM images, the increment in monomer concentration gives significant effect on morphologies and eventually affects the electrochemical properties. PEDOT electrodeposited from 10 mM solution showed excellent electrochemical properties with the highest specific capacitance value of 12.8 mF/cm2.

  4. The role of cyclase-associated protein in regulating actin filament dynamics – more than a monomer-sequestration factor

    OpenAIRE

    Ono, Shoichiro

    2013-01-01

    Dynamic reorganization of the actin cytoskeleton is fundamental to a number of cell biological events. A variety of actin-regulatory proteins modulate polymerization and depolymerization of actin and contribute to actin cytoskeletal reorganization. Cyclase-associated protein (CAP) is a conserved actin-monomer-binding protein that has been studied for over 20 years. Early studies have shown that CAP sequesters actin monomers; recent studies, however, have revealed more active roles of CAP in a...

  5. The C-terminal dimerization motif of cyclase-associated protein is essential for actin monomer regulation.

    Science.gov (United States)

    Iwase, Shohei; Ono, Shoichiro

    2016-12-01

    Cyclase-associated protein (CAP) is a conserved actin-regulatory protein that functions together with actin depolymerizing factor (ADF)/cofilin to enhance actin filament dynamics. CAP has multiple functional domains, and the function to regulate actin monomers is carried out by its C-terminal half containing a Wiskott-Aldrich Syndrome protein homology 2 (WH2) domain, a CAP and X-linked retinitis pigmentosa 2 (CARP) domain, and a dimerization motif. WH2 and CARP are implicated in binding to actin monomers and important for enhancing filament turnover. However, the role of the dimerization motif is unknown. Here, we investigated the function of the dimerization motif of CAS-2, a CAP isoform in the nematode Caenorhabditis elegans, in actin monomer regulation. CAS-2 promotes ATP-dependent recycling of ADF/cofilin-bound actin monomers for polymerization by enhancing exchange of actin-bound nucleotides. The C-terminal half of CAS-2 (CAS-2C) has nearly as strong activity as full-length CAS-2. Maltose-binding protein (MBP)-tagged CAS-2C is a dimer. However, MBP-CAS-2C with a truncation of either one or two C-terminal β-strands is monomeric. Truncations of the dimerization motif in MBP-CAS-2C nearly completely abolish its activity to sequester actin monomers from polymerization and enhance nucleotide exchange on actin monomers. As a result, these CAS-2C variants, also in the context of full-length CAS-2, fail to compete with ADF/cofilin to release actin monomers for polymerization. CAS-2C variants lacking the dimerization motif exhibit enhanced binding to actin filaments, which is mediated by WH2. Taken together, these results suggest that the evolutionarily conserved dimerization motif of CAP is essential for its C-terminal region to exert the actin monomer-specific regulatory function.

  6. Updated evaluation of the migration of styrene monomer and oligomers from polystyrene food contact materials to foods and food simulants.

    Science.gov (United States)

    Genualdi, Susan; Nyman, Patricia; Begley, Timothy

    2014-04-01

    Due to the 2011 labelling of styrene monomer as "reasonably anticipated to be a human carcinogen" by the National Institutes of Health's National Toxicology Program (NTP) and the controversy over whether styrene oligomers mimic the physiological effects of estrogen, an updated review of styrene monomer and oligomers in food and food contact materials (FCMs) was performed. The concentrations of styrene monomer and oligomers were determined in 24 polystyrene (PS) products and ranged from 9.3 to 3100 mg kg(-1) for the styrene monomer, 130-2900 mg kg(-1) for the sum of three styrene dimers, and 220-16,000 mg kg(-1) for the sum of six styrene trimers. Foods in contact with PS packaging had styrene monomer concentrations ranging from 2.6 to 163 ng g(-1); dimer concentrations from the limit of quantitation (LOQ) to 4.8 ng g(-1) and trimer concentrations were all below the LOQ (2 ng g(-1)). Diffusion coefficients (Dp) and partition coefficients (K) were also calculated for styrene dimers and trimers. The results presented here indicate that styrene monomer concentrations in foods have not significantly changed since the 1980s and monomer concentrations in food packaging quantified in this study were all below USFDA limits. Although styrene dimers and trimers are present in higher concentrations in PS FCMs than the monomer, their migration to food is limited because of their high K values (4 × 10(2) to 2 × 10(6)) and their low diffusion coefficients in PS products. Additionally, diffusion coefficients calculated using USFDA-recommended food simulants and Arrhenius plots describing the temperature dependence of styrene dimers and trimers can be used in future calculations of dietary intake of the styrene oligomers.

  7. Molecular weight distribution of A2-B2 type condensation polymers in the presence of capping monomer C

    Institute of Scientific and Technical Information of China (English)

    张连来; 廖琦; 顾宜; 江璐霞; 蔡兴贤

    1996-01-01

    The molecular weight distribution of A2-B2 type condensation polymers in the presence of capping monomer C has been derived with statistical calculation and Monte Carlo simulation methods. The Monte Carlo simulation result agrees with that of statistical calculation. The number distribution function and weight distribution function of seven types of molecules existing in A2-B2-C system have been obtained. The effect of reactivity of capping monomer C on these distributions are discussed.

  8. The Use of Commercial Non-Hazardous Air Pollutant Monomers to Optimize the Properties of Fatty Acid-Based Resins

    Science.gov (United States)

    2009-05-01

    Reviewing all of the data, it was found that the di-functional monomers produced resins with lower viscosities, higher modulus, and higher Tg than the...to storage modulus Tg Glass transition temperature of polymer TGA Thermogravimetric analysis UPE Unsaturated polyester VE Vinyl ester...The Use of Commercial Non-Hazardous Air Pollutant Monomers to Optimize the Properties of Fatty Acid-Based Resins by John J. La Scala, Priya

  9. Computational Modeling and Theoretical Calculations on the Interactions between Spermidine and Functional Monomer (Methacrylic Acid in a Molecularly Imprinted Polymer

    Directory of Open Access Journals (Sweden)

    Yujie Huang

    2015-01-01

    Full Text Available This paper theoretically investigates interactions between a template and functional monomer required for synthesizing an efficient molecularly imprinted polymer (MIP. We employed density functional theory (DFT to compute geometry, single-point energy, and binding energy (ΔE of an MIP system, where spermidine (SPD and methacrylic acid (MAA were selected as template and functional monomer, respectively. The geometry was calculated by using B3LYP method with 6-31+(d basis set. Furthermore, 6-311++(d, p basis set was used to compute the single-point energy of the above geometry. The optimized geometries at different template to functional monomer molar ratios, mode of bonding between template and functional monomer, changes in charge on natural bond orbital (NBO, and binding energy were analyzed. The simulation results show that SPD and MAA form a stable complex via hydrogen bonding. At 1 : 5 SPD to MAA ratio, the binding energy is minimum, while the amount of transferred charge between the molecules is maximum; SPD and MAA form a stable complex at 1 : 5 molar ratio through six hydrogen bonds. Optimizing structure of template-functional monomer complex, through computational modeling prior synthesis, significantly contributes towards choosing a suitable pair of template-functional monomer that yields an efficient MIP with high specificity and selectivity.

  10. A review of our development of dental adhesives--effects of radical polymerization initiators and adhesive monomers on adhesion.

    Science.gov (United States)

    Ikemura, Kunio; Endo, Takeshi

    2010-03-01

    This paper reviews the development of dental adhesives by collating information of related studies from original scientific papers, reviews, and patent literatures. Through our development, novel radical polymerization initiators, adhesive monomers, and microcapsules were synthesized, and their effects on adhesion were investigated. It was found that 5-monosubstituted barbituric acid (5-MSBA)-containing ternary initiators in conjunction with adhesive monomers contributed to effective adhesion with good polymerization reactivity. Several kinds of novel adhesive monomers bearing carboxyl group, phosphonic acid group or sulfur-containing group were synthesized, and investigated their multi-purpose bonding functions. It was suggested that the flexible methylene chain in the structure of adhesive monomers played a pivotal role in their enhanced bonding durability. It was found that the combination of acidic monomers with sulfur-containing monomer markedly improved adhesion to enamel, dentin, porcelain, alumina, zirconia, non-precious metals and precious metals. A new poly(methyl methacrylate) (PMMA)-type adhesive resin comprising microencapsulated polymerization initiators was also found to exhibit both good formulation stability and excellent adhesive property.

  11. SNPing away at candidate genes.

    Science.gov (United States)

    Suchard, M A; Bailey, J N; Elashoff, D A; Sinsheimer, J S

    2001-01-01

    We develop regression methodology to identify subsets of single nucleotide polymorphisms (SNPs) within candidate genes related to quantitative traits and apply our methods to the simulated Genetic Analysis Workshop (GAW) 12 data set. In the data set we find 694 SNP loci with minimum allele frequencies of at least 0.01. We assume an additive casual model between these SNPs and all five quantitative traits. After initial screening using one-way analysis of variance, we employ a computationally efficient, simulated annealing algorithm to select among all possible subsets of SNP loci, using a generalization of Mallows' Cp as our optimality criterion. The simple transition kernel we develop evaluates new subsets in O(1), by requiring just three arithmetic operations to calculate the proposed RSS based on the Gauss-Jordan pivot. We identify an SNP loci located at 6-5782 related to traits 2 and 3 and several sites on gene 2 related to trait 5 using a subsample of 1,000 individuals and the full data set (n = 8,250) for comparison.

  12. High-resolution structure of a retroviral protease folded as a monomer

    Energy Technology Data Exchange (ETDEWEB)

    Gilski, Miroslaw [A. Mickiewicz University, 60-780 Poznan (Poland); Polish Academy of Sciences, 61-704 Poznan (Poland); Kazmierczyk, Maciej; Krzywda, Szymon [A. Mickiewicz University, 60-780 Poznan (Poland); Zábranská, Helena [Academy of Sciences of the Czech Republic, 166 10 Prague (Czech Republic); Cooper, Seth; Popović, Zoran [University of Washington, Box 352350, Seattle, WA 98195 (United States); Khatib, Firas; DiMaio, Frank; Thompson, James; Baker, David [University of Washington, Box 357350, Seattle, WA 98195 (United States); Pichová, Iva [Academy of Sciences of the Czech Republic, 166 10 Prague (Czech Republic); Jaskolski, Mariusz, E-mail: mariuszj@amu.edu.pl [A. Mickiewicz University, 60-780 Poznan (Poland); Polish Academy of Sciences, 61-704 Poznan (Poland)

    2011-11-01

    The crystal structure of Mason–Pfizer monkey virus protease folded as a monomer has been solved by molecular replacement using a model generated by players of the online game Foldit. The structure shows at high resolution the details of a retroviral protease folded as a monomer which can guide rational design of protease dimerization inhibitors as retroviral drugs. Mason–Pfizer monkey virus (M-PMV), a D-type retrovirus assembling in the cytoplasm, causes simian acquired immunodeficiency syndrome (SAIDS) in rhesus monkeys. Its pepsin-like aspartic protease (retropepsin) is an integral part of the expressed retroviral polyproteins. As in all retroviral life cycles, release and dimerization of the protease (PR) is strictly required for polyprotein processing and virion maturation. Biophysical and NMR studies have indicated that in the absence of substrates or inhibitors M-PMV PR should fold into a stable monomer, but the crystal structure of this protein could not be solved by molecular replacement despite countless attempts. Ultimately, a solution was obtained in mr-rosetta using a model constructed by players of the online protein-folding game Foldit. The structure indeed shows a monomeric protein, with the N- and C-termini completely disordered. On the other hand, the flap loop, which normally gates access to the active site of homodimeric retropepsins, is clearly traceable in the electron density. The flap has an unusual curled shape and a different orientation from both the open and closed states known from dimeric retropepsins. The overall fold of the protein follows the retropepsin canon, but the C{sup α} deviations are large and the active-site ‘DTG’ loop (here NTG) deviates up to 2.7 Å from the standard conformation. This structure of a monomeric retropepsin determined at high resolution (1.6 Å) provides important extra information for the design of dimerization inhibitors that might be developed as drugs for the treatment of retroviral infections

  13. Prediction of monomer isomery in Florine: a workflow dedicated to nonribosomal peptide discovery.

    Directory of Open Access Journals (Sweden)

    Thibault Caradec

    Full Text Available Nonribosomal peptides represent a large variety of natural active compounds produced by microorganisms. Due to their specific biosynthesis pathway through large assembly lines called NonRibosomal Peptide Synthetases (NRPSs, they often display complex structures with cycles and branches. Moreover they often contain non proteogenic or modified monomers, such as the D-monomers produced by epimerization. We investigate here some sequence specificities of the condensation (C and epimerization (E domains of NRPS that can be used to predict the possible isomeric state (D or L of each monomer in a putative peptide. We show that C- and E- domains can be divided into 2 sub-regions called Up-Seq and Down-Seq. The Up-Seq region corresponds to an InterPro domain (IPR001242 and is shared by C- and E-domains. The Down-Seq region is specific to the enzymatic activity of the domain. Amino-acid signatures (represented as sequence logos previously described for complete C-and E-domains have been restricted to the Down-Seq region and amplified thanks to additional sequences. Moreover a new Down-Seq signature has been found for Ct-domains found in fungi and responsible for terminal cyclization of the peptides. The identification of these signatures has been included in a workflow named Florine, aimed to predict nonribosomal peptides from NRPS sequence analyses. In some cases, the prediction of isomery is guided by genus-specific rules. Florine was used on a Pseudomonas genome to allow the determination of the type of pyoverdin produced, the update of syringafactin structure and the identification of novel putative products.

  14. A robust and versatile photoinduced living polymerization of conjugated and unconjugated monomers and its oxygen tolerance.

    Science.gov (United States)

    Xu, Jiangtao; Jung, Kenward; Atme, Amir; Shanmugam, Sivaprakash; Boyer, Cyrille

    2014-04-09

    Controlled/living radical polymerization techniques have transformed polymer chemistry in the last few decades, affording the production of polymers with precise control over both molecular weights and architectures. It is now possible to synthesize almost an infinite variety of macromolecules using nonspecialized equipment, finding applications in high-tech industry. However, they have several shortcomings. Until recently, living radical polymerizations could not be controlled by an external stimulus, such as visible light, pH, mechanical, chemical, etc. Moreover, they are usually sensitive to trace amounts of oxygen in the system. In this Article, we report a photoinduced living polymerization technique, which is able to polymerize a large range of monomers, including conjugated and unconjugated monomers, using ultralow concentrations of an iridium-based photoredox catalyst (typically 1 ppm to monomers) and a low energy visible LED as the light source (1-4.8 W, λ(max) = 435 nm). The synthesis of homopolymers with molecular weights ranging from 1000 to 2,000,000 g/mol was successfully achieved with narrow molecular weight distributions (M(w)/M(n) < 1.3). In addition, chain extensions of poly(methacrylate)s, poly(styrene), poly(N-vinyl pyrrolidinone), poly(vinyl ester)s, and poly(acrylate)s were performed to prepare diblock copolymers. The reusability of the catalyst was demonstrated by the synthesis of a decablock polymer by multiple chain extensions. Most importantly, this process was employed to prepare well-defined polymers and multiblock copolymers in the presence of air.

  15. A Research on the Comparison of the MultipleIntelligince Types of the Candidates Who Succeeded and Failedinthe Entrance Exams of Physical Educationand Sports School

    Directory of Open Access Journals (Sweden)

    Murat KUL

    2014-07-01

    Full Text Available The purpose of the study , candidates who participated in a special aptitude test of Physical Education and Sports School are compared those who were eligible to register with the win of Multiple Inte lligence Areas. In the research Scan model was used. Within the investigation, in 785 candidates who applied Bartin Universty School of Physical Education and Sports Special Ability Test for 2013 - 2014 academic year, 536 volunteer candidates who have average age x yaş = 21.15± 2.66 constitude. As data collection tool, belogns to the candidates personal information form and “Multiple Intelligences Inventory” which was developed by Özden (2003 for he identification of multiple intellegences was applied. Reliability coefficient was discovered as .96. In evaluation of data, SPSS data an alysis program was used. In evaluation of data, frequency, average, standard, deviation from descriptive statistical techniques was used. Also by taking into account normal distribution of the data, Independent Sample T - test of statistical techniques was u sed. In considering the findings of the study “Bodily - Kinesthetic Intelligence” which is a field of Multiple Intelligences of candidates as statistically significant diffirence was found in the area. Candidates winning higher than avarage scores candidates who can not win are seen to have. Also, “Social - Interpersonal Intelligence” of candidates qualifing to register with who can not qualify to register statistically significant results were observed in the levels. Winning candidates in this area compared t o the candidates who win more than others, it is concluded that they carry the dominant features. As a result of “Verbal - Linguistic Intelligence”, “Logical - Mathematical Intelligence”, “Musical - Rhythmic Intelligence”, “Bodily - Kinesthetic Intelligence, “Soci al - Interpersonal Intelligence” of Multiple Intelligence Areas candidates who participated in Physical Education

  16. Environmental effects on the lignin model monomer, vanillyl alcohol, studied by raman spectroscopy

    DEFF Research Database (Denmark)

    Larsen, Kiki Lyster; Barsberg, Søren Talbro

    2011-01-01

    units, respectively. Raman spectroscopy gives valuable knowledge on lignin and has a large potential for further developments. Thus in the present work we show how the use of electronic structure theory can support the study of environmental effects on lignin Raman bands. Raman spectra of the lignin...... model monomer, vanillyl alcohol (G type), dissolved in different solvents were compared to investigate such effects on the Raman band shapes and positions. Density functional theory combined with the polarizable continuum model were applied to assign the observed bands and tested for prediction accuracy...

  17. Synthesis and Characterization of Oligodeoxyribonucleotides Modified with 2'-Amino-α-l-LNA Adenine Monomers

    DEFF Research Database (Denmark)

    Andersen, Nicolai K; Anderson, Brooke A; Wengel, Jesper

    2013-01-01

    The development of conformationally restricted nucleotide building blocks continues to attract considerable interest because of their successful use within antisense, antigene, and other gene-targeting strategies. Locked nucleic acid (LNA) and its diastereomer α-l-LNA are two interesting examples...... (ONs) modified with 2'-amino-α-l-LNA adenine monomers W-Z. The synthesis of the target phosphoramidites 1-4 is initiated from pentafuranose 5, which upon Vorbrüggen glycosylation, O2'-deacylation, O2'-activation and C2'-azide introduction yields nucleoside 8. A one-pot tandem Staudinger...

  18. 1,3-Diphenylethenylcarbazolyl-Based Monomer for Cross-Linked Hole Transporting Layers

    Directory of Open Access Journals (Sweden)

    Maryte Daskeviciene

    2015-05-01

    Full Text Available A new cross-linkable monomer containing 1,3-diphenylethenylcarbazolyl-based hole-transporting moieties and four reactive epoxy groups, was prepared by a multistep synthesis route from 1,3-bis(2,2-diphenylethenyl-9H-carbazol-2-ol and its application for the in situ formation of cross-linked hole transporting layers was investigated. A high concentration of flexible aliphatic epoxy chains ensures good solubility and makes this compound an attractive cross-linking agent. The synthesized compounds were characterized by various techniques, including differential scanning calorimetry, xerographic time of flight, and electron photoemission in air methods.

  19. Preparation, isolation, and characterization of cutin monomers and oligomers from tomato peels.

    Science.gov (United States)

    Osman, S F; Irwin, P; Fett, W F; O'Connor, J V; Parris, N

    1999-02-01

    Cutin in tomato peels was depolymerized in methanolic base to yield cutin monomers or a mixture of cutin oligomers. These products were isolated by typical solvent extraction methods or by precipitation, and the isolates were characterized by chromatographic and spectroscopic analyses. It was determined that the compositions of the isolates from both isolation procedures were similar, although solvent extraction gave higher yields. However, the precipitation method, which is easy to carry out and avoids the use of undesirable organic solvents, may be preferable in commercial processes for recovering these compounds.

  20. Modification of biodegradable polymers by radiation crosslinking technique with polyfunctional monomers

    Energy Technology Data Exchange (ETDEWEB)

    Yoshii, Fumio E-mail: yoshii@taka.jaeri.go.jp; Suhartini, Meri; Nagasawa, Naotsugu; Mitomo, Hiroshi; Kume, Tamikazu

    2003-08-01

    Poly({epsilon}-caprolactone) (PCL) and poly(butylene succinate-co-adipate) (PBSA) were electron beam-irradiated in the presence of five different polyfunctional monomers at ambient temperature. Trimethallyl isocyanurate (TMAIC) has been found to greatly enhance the radiation crosslinking of PCL and PBSA. It was pointed out that the optimum yield of gel fraction can be achieved when the polymers were irradiated at a dose of 50 kGy in the presence of 1% TMAIC. High gel fraction largely improves heat stability of PBSA, while biodegradability evaluated by soil burial test of the crosslinked polymers is slightly retarded, however they are effectively destroyed with a slightly smaller rate.

  1. Modification of biodegradable polymers by radiation crosslinking technique with polyfunctional monomers

    Science.gov (United States)

    Yoshii, Fumio; Suhartini, Meri; Nagasawa, Naotsugu; Mitomo, Hiroshi; Kume, Tamikazu

    2003-08-01

    Poly(ɛ-caprolactone) (PCL) and poly(butylene succinate-co-adipate) (PBSA) were electron beam-irradiated in the presence of five different polyfunctional monomers at ambient temperature. Trimethallyl isocyanurate (TMAIC) has been found to greatly enhance the radiation crosslinking of PCL and PBSA. It was pointed out that the optimum yield of gel fraction can be achieved when the polymers were irradiated at a dose of 50 kGy in the presence of 1% TMAIC. High gel fraction largely improves heat stability of PBSA, while biodegradability evaluated by soil burial test of the crosslinked polymers is slightly retarded, however they are effectively destroyed with a slightly smaller rate.

  2. Organic Crystal Engineering of Thermosetting Cyanate Ester Monomers: Influence of Structure on Melting Point

    Science.gov (United States)

    2016-05-27

    heating baseline does show a modest non - linearity due to its nearness to the onset of the wide melting peak. Because we elected not to use heating...Guenthner, Sean M. Ramirez , Michael D. Ford, Denisse Soto, Jerry A. Boatz, Kamran B. Ghiassi and Joseph M. Mabry 5d. PROJECT NUMBER 5e. TASK...longer Si-C bonds for C-C bonds in the monomer chemical structure results in the “unlocking” of new degrees of freedom in non -interlocking molecules

  3. Construction of Multi-Chromophoric Spectra from Monomer Data: Applications to Resonant Energy Transfer

    CERN Document Server

    Chenu, Aurélia

    2016-01-01

    We develop a model that establishes a quantitative link between the physical properties of molecular aggregates and their constituent building blocks. The relation is built on the coherent potential approximation, calibrated against exact results, and proven reliable for a wide range of parameters. It provides a practical method to compute spectra and transfer rates in multi-chromophoric systems from experimentally accessible monomer data. Applications to F\\"orster energy transfer reveal optimal transfer rates as functions of both the system-bath coupling and intra-aggregate coherence.

  4. INS as a probe of inter-monomer angles in polymers

    CERN Document Server

    Eijck, L V; Grozema, F C; Schepper, I M D; Kearley, G J

    2002-01-01

    The angle between monomers in conjugated polymers plays an important role in their conductivity. The vibrational spectrum is sensitive to this angle and can be used to probe the distribution of angles in poorly crystalline systems. We show that the INS spectrum is correctly calculated for bithiophene and shows the molecule to be planar in the solid - in agreement with crystallographic measurements. Poor agreement between observed and calculated spectra in the 700-cm sup - sup 1 region may be due to dynamic coupling, but this does not detract from the angle-sensitivity of the spectra. (orig.)

  5. Construction of Multichromophoric Spectra from Monomer Data: Applications to Resonant Energy Transfer

    Science.gov (United States)

    Chenu, Aurélia; Cao, Jianshu

    2017-01-01

    We develop a model that establishes a quantitative link between the physical properties of molecular aggregates and their constituent building blocks. The relation is built on the coherent potential approximation, calibrated against exact results, and proven reliable for a wide range of parameters. It provides a practical method to compute spectra and transfer rates in multichromophoric systems from experimentally accessible monomer data. Applications to Förster energy transfer reveal optimal transfer rates as functions of both the system-bath coupling and intra-aggregate coherence.

  6. Glucagon stop-go kinetics supports a monomer-trimer fibrillation model

    CERN Document Server

    Kosmrlj, Andrej; Kyrsting, Anders; Otzen, Daniel E; Oddershede, Lene B; Jensen, Mogens H

    2014-01-01

    We investigate in vitro fibrillation kinetics of the hormone peptide glucagon at various concentrations using confocal microscopy and determine the glucagon fibril persistence length $60 \\mu\\textrm{m}$. At all concentrations we observe that periods of individual fibril growth are interrupted by periods of stasis. The growth probability is large at high and low concentrations and is reduced for intermediate glucagon concentrations. To explain this behavior we propose a simple model, where fibrils come in two forms, one built entirely from glucagon monomers and one entirely from glucagon trimers. The opposite building blocks act as fibril growth blockers, and this generic model reproduces experimental behavior well.

  7. Teacher Candidates' Communication Skills and Communicator Styles

    OpenAIRE

    Cem ÇUHADAR; Özgür, Hasan; Akgün, Fatma; GÜNDÜZ, Şemseddin

    2015-01-01

    The purpose of this study is to find out the relationship between the communication skills and the communicator styles of teacher candidates. This research was conducted among the senior class students, studying at Trakya University, Faculty of Education in the fall semester of the 2012-2013 academic year. 205 women and 110 men, in a total of 315 teacher candidates participated in the research. As a result, it has been observed that the teacher candidates bear animated/expressive features the...

  8. Graft copolymers of polyurethane with various vinyl monomers via radiation-induced miniemulsion polymerization: Influential factors to grafting efficiency and particle morphology

    Energy Technology Data Exchange (ETDEWEB)

    Wang Hua [CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, University of Science and Technology of China (USTC), Hefei, Anhui 230026 (China); Wang Mozhen [CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, University of Science and Technology of China (USTC), Hefei, Anhui 230026 (China)], E-mail: pstwmz@ustc.edu.cn; Ge Xuewu [CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, University of Science and Technology of China (USTC), Hefei, Anhui 230026 (China)], E-mail: xwge@ustc.edu.cn

    2009-02-15

    Graft copolymers of polyurethane (PU) with various vinyl monomers were synthesized through a one-pot but two-step miniemulsion polymerization process. Firstly, the polycondensation of isophorone diisocyanate (IPDI) with hydroxyl-terminated polybutadiene (HTPB) had been performed in aqueous miniemulsion at 40 deg. C in order to obtain PU dispersions. Consecutively, an in-situ graft copolymerization of the vinyl monomers with the synthesized PU was initiated by {gamma}-ray radiation at room temperature. The grafting efficiency of PU with vinyl monomer (G{sub PU/monomer}) was calculated from {sup 1}H NMR spectra and the particle morphology of the final hybrid latex was observed by transmission electron microscopy (TEM). As there was no monomer transferring in miniemulsion system, homogenous hybrid particles would be synthesized provided that the monomer was miscible with PU, such as styrene. With the increase of the polarity of the monomer, the compatibility of PU with monomer decreased. G{sub PU/monomer} varied as G{sub PU/styrene}(37%)>G{sub PU/butyl} {sub acrylate} {sub (BA)}(21%)>G{sub PU/methyl} {sub methacrylate} {sub (MMA)}(12%). The proportion of homogeneous nucleation would increase as the hydrophilicity of the monomer increased. High temperature would destabilize the miniemulsion so as to result in a less grafting efficiency. Compared to the phase separation during the seeded emulsion polymerization, the miniemulsion polymerization method facilitated the preparation of homogeneous materials owing to its monomer droplet nucleation mechanism.

  9. A conserved cysteine residue is involved in disulfide bond formation between plant plasma membrane aquaporin monomers.

    Science.gov (United States)

    Bienert, Gerd P; Cavez, Damien; Besserer, Arnaud; Berny, Marie C; Gilis, Dimitri; Rooman, Marianne; Chaumont, François

    2012-07-01

    AQPs (aquaporins) are conserved in all kingdoms of life and facilitate the rapid diffusion of water and/or other small solutes across cell membranes. Among the different plant AQPs, PIPs (plasma membrane intrinsic proteins), which fall into two phylogenetic groups, PIP1 and PIP2, play key roles in plant water transport processes. PIPs form tetramers in which each monomer acts as a functional channel. The intermolecular interactions that stabilize PIP oligomer complexes and are responsible for the resistance of PIP dimers to denaturating conditions are not well characterized. In the present study, we identified a highly conserved cysteine residue in loop A of PIP1 and PIP2 proteins and demonstrated by mutagenesis that it is involved in the formation of a disulfide bond between two monomers. Although this cysteine seems not to be involved in regulation of trafficking to the plasma membrane, activity, substrate selectivity or oxidative gating of ZmPIP1s (Zm is Zea mays), ZmPIP2s and hetero-oligomers, it increases oligomer stability under denaturating conditions. In addition, when PIP1 and PIP2 are co-expressed, the loop A cysteine of ZmPIP1;2, but not that of ZmPIP2;5, is involved in the mercury sensitivity of the channels.

  10. Monomer composition of polysaccharides of seed cell walls and the taxonomy of the Vochysiaceae.

    Science.gov (United States)

    Mayworm, M A; Buckeridge, M S; Salatino, A

    2000-11-01

    The distribution of polysaccharides from the seed cell walls of 57 samples of Vochysiaceae native to Brazil were studied, comprising 16 species distributed among the genera Callisthene, Qualea, Salvertia and Vochysia. The polysaccharides were extracted with hot water, then hydrolyzed with the resulting monomers analyzed by HPLC. All samples yielded arabinose, galactose, glucose. mannose and rhamnose, the relative amounts of each monomer, however, varying from one sample to another. Arabinose was always the predominant component, which implies that it might possibly be used as a marker of the Vochysiaceae. The quantitative distribution of monosaccharides was similar between the species of Qualea and Callisthene, characterized by the predominance of arabinose and mannose, and between the species of Salvertia and Vochysia, which contained higher amounts of arabinose and galactose. Such results are consistent with affinities inferred from floral morphology, wood anatomy and molecular data. Substantial intraspecific variation was observed for some species. UPGMA analysis based on the distribution of the monosaccharides reveals two main clusters, according to the links commented above. The resultant phenogram is not coherent with the current sectional classification of the Vochysiaceae, but the differences in the monosaccharides distribution between the two clusters are strongly supported by ANOVA.

  11. EFFECT OF GAMMA RAYS IN THE PREPARATION OF POLYMER AND HYDROGEL FROM ACRYLAMIDE MONOMER

    Institute of Scientific and Technical Information of China (English)

    M. M. Alam; M. F. Mina; F. Akhtar

    2003-01-01

    The formation of polymer and hydrogel from aqueous solutions having 20, 30 and 40% concentrations of acrylamide monomer by γ-ray irradiation processing in the dose range 0.06-30 kGy using a Co-60 source and their characterization have been observed. Polymer conversion and gel fraction are found to depend on radiation doses. Polymer conversion increases with the increase of dose, depending on the solution concentration, where maximum conversion is achieved at 0.18, 0.16 and 0.10 kGy for 20%, 30% and 40% concentrations, respectively. On the other hand, gel fraction increases with dose from the gel point (0.12 kGy) for all concentrations, where 100% conversion of gel occurs at doses ≥ 5 kGy. Tensile strength, viscosity and molecular weight (Mw) of polymer samples increase with both the dose and the concentration, showing a high value of Mw up to ≈108. Swelling of hydrogels under water with respect to time varies due to the variation of cross-linking density formed in the gels and the maximum swelling mainly occurs within 24 h. A remarkable change of surface morphology reveals characteristic features of monomer, polymer and hydrogel films.

  12. Synthesis of Molecularly Imprinted Polymers for Amino Acid Derivates by Using Different Functional Monomers

    Directory of Open Access Journals (Sweden)

    Sonia Scorrano

    2011-03-01

    Full Text Available Fmoc-3-nitrotyrosine (Fmoc-3-NT molecularly imprinted polymers (MIPs were synthesized to understand the influence of several functional monomers on the efficiency of the molecular imprinting process. Acidic, neutral and basic functional monomers, such as acrylic acid (AA, methacrylic acid (MAA, methacrylamide (MAM, 2-vinylpyridine (2-VP, 4-vinylpyridine (4-VP, have been used to synthesize five different polymers. In this study, the MIPs were tested in batch experiments by UV-visible spectroscopy in order to evaluate their binding properties. The MIP prepared with 2-VP exhibited the highest binding affinity for Fmoc-3NT, for which Scatchard analysis the highest association constant (2.49 × 104 M−1 was obtained. Furthermore, titration experiments of Fmoc-3NT into acetonitrile solutions of 2-VP revealed a stronger bond to the template, such that a total interaction is observed. Non-imprinted polymers as control were prepared and showed no binding affinities for Fmoc-3NT. The results are indicative of the importance of ionic bonds formed between the –OH residues of the template molecule and the pyridinyl groups of the polymer matrix. In conclusion, 2-VP assists to create a cavity which allows better access to the analytes.

  13. Preparation and characterization of monomers to tetramers of a collagen-like domain from Streptococcus pyogenes.

    Science.gov (United States)

    Peng, Yong Y; Stoichevska, Violet; Howell, Linda; Madsen, Soren; Werkmeister, Jerome A; Dumsday, Geoff J; Ramshaw, John A M

    2014-01-01

    The collagen like domain Scl2 from Streptococcus pyogenes has been proposed as a potential biomedical material. It is non-cytotoxic and non-immunogenic and can be prepared in good yield in fermentation. The Scl2 collagen domain is about a quarter of the length, 234 residues, of the main collagen type, mammalian type I collagen (1014 residues) that is currently used in biomedical devices. In the present study we have made constructs comprising 1 to 4 copies of the Scl2 collagen domain, plus these same constructs with a CysCys sequence at the C-terminal, analogous to that found in mammalian type III collagens. The yields of these constructs were examined from 2 L fermentation studies. The yields of both series declined with increasing size. Circular dichroism showed that the addition of further collagen domains did not lead to a change in the melting temperature compared to the monomer domain. Addition of the CysCys sequence led to a small additional stabilization of about 2-3°C for the monomer construct when the folding (V) domain was present.

  14. Therapeutic TNF Inhibitors can Differentially Stabilize Trimeric TNF by Inhibiting Monomer Exchange

    Science.gov (United States)

    van Schie, Karin A.; Ooijevaar-de Heer, Pleuni; Dijk, Lisanne; Kruithof, Simone; Wolbink, Gertjan; Rispens, Theo

    2016-01-01

    Tumor necrosis factor (TNF) is a homotrimeric cytokine that is a key mediator of inflammation. It is unstable at physiological concentrations and slowly converts into an inactive form. Here, we investigated the mechanism of this process by using a Förster resonance energy transfer (FRET) assay that allowed monitoring of monomeric subunit exchange in time. We observed continuous exchange of monomeric subunits even at concentrations of TNF high enough to maintain its bioactivity. The kinetics of this process closely corresponds with the appearance of monomeric subunits and disappearance of trimeric TNF in time at ng/ml concentrations as monitored by high-performance size-exclusion chromatography (HP-SEC). Furthermore, of the five therapeutic TNF inhibitors that are currently used in the clinic, three (adalimumab, infliximab, etanercept) were found to completely inhibit the monomer exchange reaction and stabilize TNF trimers, whereas golimumab and certolizumab could not prevent monomer exchange, but did slow down the exchange process. These differences were not correlated with the affinities of the TNF inhibitors, measured with both surface plasmon resonance (SPR) and in fluid phase using fluorescence-assisted HP-SEC. The stabilizing effect of these TNF inhibitors might result in prolonged residual TNF bioactivity under conditions of incomplete blocking, as observed in vitro for adalimumab. PMID:27605058

  15. A thioacidolysis method tailored for higher-throughput quantitative analysis of lignin monomers.

    Science.gov (United States)

    Harman-Ware, Anne E; Foster, Cliff; Happs, Renee M; Doeppke, Crissa; Meunier, Kristoffer; Gehan, Jackson; Yue, Fengxia; Lu, Fachuang; Davis, Mark F

    2016-10-01

    Thioacidolysis is a method used to measure the relative content of lignin monomers bound by β-O-4 linkages. Current thioacidolysis methods are low-throughput as they require tedious steps for reaction product concentration prior to analysis using standard GC methods. A quantitative thioacidolysis method that is accessible with general laboratory equipment and uses a non-chlorinated organic solvent and is tailored for higher-throughput analysis is reported. The method utilizes lignin arylglycerol monomer standards for calibration, requires 1-2 mg of biomass per assay and has been quantified using fast-GC techniques including a Low Thermal Mass Modular Accelerated Column Heater (LTM MACH). Cumbersome steps, including standard purification, sample concentrating and drying have been eliminated to help aid in consecutive day-to-day analyses needed to sustain a high sample throughput for large screening experiments without the loss of quantitation accuracy. The method reported in this manuscript has been quantitatively validated against a commonly used thioacidolysis method and across two different research sites with three common biomass varieties to represent hardwoods, softwoods, and grasses. © 2016 The Authors. Biotechnology Journal published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Synthesis of star-shaped pyrrole and thiophene functionalized monomers and optoelectrochemical properties of corresponding copolymers

    Energy Technology Data Exchange (ETDEWEB)

    Ak, Metin [Middle East Technical University, Department of Chemistry, 06531 Ankara (Turkey); Pamukkale University, Department of Chemistry, 20020 Denizli (Turkey); Toppare, Levent [Middle East Technical University, Department of Chemistry, 06531 Ankara (Turkey)], E-mail: toppare@metu.edu.tr

    2009-04-15

    Star-shaped thiophene and pyrrole functionalized monomers namely 2,4,6-tris(4-(1H-pyrrol-1-yl)phenoxy)-1,3,5-triazine (TriaPy) and 2,4,6-tris(4-(1H-pyrrol-1-yl)phenoxy)-1,3,5-triazine (TriaTh) were synthesized from 2,4,6-trichloro-1,3,5-triazine, thiophen-3-ylmethanol and 4-(1H-pyrrol-1-yl)phenol. Electrochemical copolymerization of monomers with thiophene and pyrrole was achieved in tetrabutylammonium tetrafluoroborate/acetonitrile (TBAFB/AN). Resulting copolymers were characterized by Fourier transform infrared (FTIR) spectrometer, cyclic voltammetry (CV) and conductivity measurements. Spectroelectrochemical analysis reflected that copolymer films have low {lambda}{sub max} for {pi}-{pi}* electronic transitions accompanied with a rather high band gap compared to polythiophene and polypyrrole. Switching abilities of copolymer films were evaluated by a kinetic study via measuring the transmittance (%T) at the maximum contrast.

  17. Recovery and Utilization of Lignin Monomers as Part of the Biorefinery Approach

    Directory of Open Access Journals (Sweden)

    Kirsten M. Davis

    2016-10-01

    Full Text Available Lignin is a substantial component of lignocellulosic biomass but is under-utilized relative to the cellulose and hemicellulose components. Historically, lignin has been burned as a source of process heat, but this heat is usually in excess of the process energy demands. Current models indicate that development of an economically competitive biorefinery system requires adding value to lignin beyond process heat. This addition of value, also known as lignin valorization, requires economically viable processes for separating the lignin from the other biomass components, depolymerizing the lignin into monomeric subunits, and then upgrading these monomers to a value-added product. The fact that lignin’s biological role is to provide biomass with structural integrity means that this heteropolymer can be difficult to depolymerize. However, there are chemical and biological routes to upgrade lignin from its native form to compounds of industrial value. Here we review the historical background and current technology of (thermo chemical depolymerization of lignin; the natural ability of microbial enzymes and pathways to utilize lignin, the current prospecting work to find novel microbial routes to lignin degradation, and some applications of these microbial enzymes and pathways; and the current chemical and biological technologies to upgrade lignin-derived monomers.

  18. The Optimization of Synthesizing Graft Copolymer of Starch with Vinyl Monomers

    Institute of Scientific and Technical Information of China (English)

    WANG Zhiyu; LIU Zuoxin

    2006-01-01

    The graft copolymerization of acrylamide (AM)/acrylic acid (AA) onto starch (St-g-pAA and St-g-p(AA-co-AM)) was carried out using an orthogonal test method. The combined effects of different reaction conditions on the water absorbency of the graft copolymers were optimized through mathematical statistical methods of range and square variance analysis. The maximum water absorbency was obtained when the ratio of dried starch to distilled water was 1∶8 (w/w), the ratio of starch to monomer 1∶6 (w/w), the initiator concentration 4.40×10-3 mol/L, the crosslinker concentration 10.86×10-2 mol/L, and the basicity to AA 0.70(mol/mol). Both the graft copolymers have an excellent water absorption capacity in distilled water and in 0.9wt% NaCl solution. It was also found that in distilled water the water absorbency of St-g-pAA was higher than that of St-g-p(AA-co-AM), while in 0.9wt% NaCl solution, the situation was just the reverse. The correlation between the water absorbency and the nature of the solution and the properties of the copolymers, which is related to the properties of the monomers, was discussed. The grafting of AA and AM onto starch was confirmed by the IR spectra of St-g-pAA and St-g-p(AA-co-AM).

  19. Multiple routes and milestones in the folding of HIV-1 protease monomer.

    Directory of Open Access Journals (Sweden)

    Massimiliano Bonomi

    Full Text Available Proteins fold on a time scale incompatible with a mechanism of random search in conformational space thus indicating that somehow they are guided to the native state through a funneled energetic landscape. At the same time the heterogeneous kinetics suggests the existence of several different folding routes. Here we propose a scenario for the folding mechanism of the monomer of HIV-1 protease in which multiple pathways and milestone events coexist. A variety of computational approaches supports this picture. These include very long all-atom molecular dynamics simulations in explicit solvent, an analysis of the network of clusters found in multiple high-temperature unfolding simulations and a complete characterization of free-energy surfaces carried out using a structure-based potential at atomistic resolution and a combination of metadynamics and parallel tempering. Our results confirm that the monomer in solution is stable toward unfolding and show that at least two unfolding pathways exist. In our scenario, the formation of a hydrophobic core is a milestone in the folding process which must occur along all the routes that lead this protein towards its native state. Furthermore, the ensemble of folding pathways proposed here substantiates a rational drug design strategy based on inhibiting the folding of HIV-1 protease.

  20. Preliminary study of acrylamide monomer decomposition during methane fermentation of dairy waste sludge.

    Science.gov (United States)

    Mroczek, Ewelina; Konieczny, Piotr; Lewicki, Andrzej; Waśkiewicz, Agnieszka; Dach, Jacek

    2016-07-01

    Polyacrylamide (PAM) used in sludge dewatering exists widely in high-solid anaerobic digestion. Acrylamide is registered in the list of chemicals demonstrating toxic, carcinogenic and mutagenic properties. Therefore, it is reasonable to ask about the mobility of such residual substances in the environment. The study was carried out to assess the impact of the mesophilic (39±1°C) and thermophilic (54±1°C) fermentation process on the level of acrylamide monomer (AMD) content in the dairy sludge. The material was analysed using high-performance liquid chromatography (HPLC) for quantification of AMD. The results indicate that the process of methane fermentation continues regardless of the temperature effects on the degradation of AMD in dairy sludge. The degree of reduction of acrylamide monomer for thermophilic fermentation is 100%, while for mesophilic fermentation it is 91%. In practice, this means that biogas technology eliminates the risk of AMD migration to plant tissue. Moreover, it should be stressed that 90% of cumulative biogas and methane production was reached one week earlier under thermophilic conditions - the dynamics of the methanisation process were over 20% faster.

  1. A thioacidolysis method tailored for higher-throughput quantitative analysis of lignin monomers

    Energy Technology Data Exchange (ETDEWEB)

    Harman-Ware, Anne E. [Bioenergy Science Center, Golden CO USA; National Bioenergy Center, National Renewable Energy Laboratory, Golden CO USA; Foster, Cliff [Great Lakes BioEnergy Research Center, Michigan State University, East Lansing MI USA; Happs, Renee M. [Bioenergy Science Center, Golden CO USA; National Bioenergy Center, National Renewable Energy Laboratory, Golden CO USA; Doeppke, Crissa [Bioenergy Science Center, Golden CO USA; National Bioenergy Center, National Renewable Energy Laboratory, Golden CO USA; Meunier, Kristoffer [Great Lakes BioEnergy Research Center, Michigan State University, East Lansing MI USA; Gehan, Jackson [Great Lakes BioEnergy Research Center, Michigan State University, East Lansing MI USA; Yue, Fengxia [Wisconsin Bioenergy Initiative, University of Wisconsin, Madison WI USA; Lu, Fachuang [Wisconsin Bioenergy Initiative, University of Wisconsin, Madison WI USA; Davis, Mark F. [Bioenergy Science Center, Golden CO USA; National Bioenergy Center, National Renewable Energy Laboratory, Golden CO USA

    2016-09-14

    Thioacidolysis is a method used to measure the relative content of lignin monomers bound by SS-O-4 linkages. Current thioacidolysis methods are low-throughput as they require tedious steps for reaction product concentration prior to analysis using standard GC methods. A quantitative thioacidolysis method that is accessible with general laboratory equipment and uses a non-chlorinated organic solvent and is tailored for higher-throughput analysis is reported. The method utilizes lignin arylglycerol monomer standards for calibration, requires 1-2 mg of biomass per assay and has been quantified using fast-GC techniques including a Low Thermal Mass Modular Accelerated Column Heater (LTM MACH). Cumbersome steps, including standard purification, sample concentrating and drying have been eliminated to help aid in consecutive day-to-day analyses needed to sustain a high sample throughput for large screening experiments without the loss of quantitation accuracy. The method reported in this manuscript has been quantitatively validated against a commonly used thioacidolysis method and across two different research sites with three common biomass varieties to represent hardwoods, softwoods, and grasses.

  2. Characterization of cluster/monomer ratio in pulsed supersonic gas jets

    Science.gov (United States)

    Gao, Xiaohui; Shim, Bonggu; Wang, Xiaoming; Downer, Mike

    2008-11-01

    While Rayleigh scatter and interferometry are standard methods for determining average cluster size and total atomic density, respectively, in cluster gas jets, determination of cluster mass fraction has required additional input from gasdynamic simulations. Here we determine cluster mass fraction experimentally with fs-time-resolved measurement of refractive index using frequency domain interferometery (FDI) after ionization and heating by a pump pulse. The essence of this method is that the negative index contribution of monomer plasma appears immediately after ionization by the pump, whereas the positive contribution of clustered plasma becomes significant only after clusters expand to a Mie resonance condition, enabling separation of monomer and cluster densities in the time domain. This method allows us to investigate various influences (nozzle geometry, temperature, etc.) on cluster fraction, which varies widely in nominally identical gas jets, and is a critical parameter in realizing phase-matched harmonic generation at high laser intensity, which would lead to an efficient table-top soft X-ray source.

  3. Short-time dynamics of monomers and dimers in quasi-two-dimensional colloidal mixtures

    Science.gov (United States)

    Sarmiento-Gómez, Erick; Villanueva-Valencia, José Ramón; Herrera-Velarde, Salvador; Ruiz-Santoyo, José Arturo; Santana-Solano, Jesús; Arauz-Lara, José Luis; Castañeda-Priego, Ramón

    2016-07-01

    We report on the short-time dynamics in colloidal mixtures made up of monomers and dimers highly confined between two glass plates. At low concentrations, the experimental measurements of colloidal motion agree well with the solution of the Navier-Stokes equation at low Reynolds numbers; the latter takes into account the increase in the drag force on a colloidal particle due to wall-particle hydrodynamic forces. More importantly, we find that the ratio of the short-time diffusion coefficient of the monomer and that of the center of mass of the dimmer is almost independent of both the dimer molar fraction, xd, and the total packing fraction, ϕ , up to ϕ ≈0.5 . At higher concentrations, this ratio displays a small but systematic increase. A similar physical scenario is observed for the ratio between the parallel and the perpendicular components of the short-time diffusion coefficients of the dimer. This dynamical behavior is corroborated by means of molecular dynamics computer simulations that include explicitly the particle-particle hydrodynamic forces induced by the solvent. Our results suggest that the effects of colloid-colloid hydrodynamic interactions on the short-time diffusion coefficients are almost identical and factorable in both species.

  4. Analytic solution of two-density integral equations for sticky Janus dumbbells with arbitrary monomer diameters

    Science.gov (United States)

    Gazzillo, Domenico; Munaò, Gianmarco; Prestipino, Santi

    2016-06-01

    We study a pure fluid of heteronuclear sticky Janus dumbbells, considered to be the result of complete chemical association between unlike species in an initially equimolar mixture of hard spheres (species A) and sticky hard spheres (species B) with different diameters. The B spheres are particles whose attractive surface layer is infinitely thin. Wertheim's two-density integral equations are employed to describe the mixture of AB dumbbells together with unbound A and B monomers. After Baxter factorization, these equations are solved analytically within the associative Percus-Yevick approximation. The limit of complete association is taken at the end. The present paper extends to the more general, heteronuclear case of A and B species with size asymmetry a previous study by Wu and Chiew [J. Chem. Phys. 115, 6641 (2001)], which was restricted to dumbbells with equal monomer diameters. Furthermore, the solution for the Baxter factor correlation functions qi j α β ( r ) is determined here in a fully analytic way, since we have been able to find explicit analytic expressions for all the intervening parameters.

  5. Structural and Vibrational Study on Monomer and Dimer Forms and Water Clusters of Acetazolamide

    Directory of Open Access Journals (Sweden)

    Aysen E. Ozel

    2013-01-01

    Full Text Available Experimental IR and Raman spectra of solid acetazolamide have been analysed by computing the molecular structures and vibrational spectra of monomer and dimer forms and water clusters of acetazolamide. The possible stable conformers of free acetazolamide molecule in the ground state were obtained by scanning the potential energy surface through the dihedral angles, D1 (1S-2C-6S-9N, D2 (4N-5C-12N-14C, and D3 (5C-12N-14C-16C. The final geometry parameters for the obtained stable conformers were determined by means of geometry optimization, carried out at DFT/B3LYP/6-31G++(d,p theory level. Afterwards the possible dimer forms of the molecule and acetazolamide-H2O clusters were formed and their energetically preferred conformations were investigated using the same method and the same level of theory. The effect of BSSE on the structure and energy of acetazolamide dimer has been investigated. The assignment of the vibrational modes was performed based on the potential energy distribution of the vibrational modes, calculated by using GAR2PED program. The experimental vibrational wavenumbers of solid acetazolamide are found to be in better agreement with the calculated wavenumbers of dimer form of acetazolamide than those of its monomeric form. NBO analysis has been performed on both monomer and dimer geometries.

  6. O-Toluic Acid Monomer and Monohydrate: Rotational Spectra, Structures, and Atmospheric Implications

    Science.gov (United States)

    Schnitzler, Elijah G.; Zenchyzen, Brandi L. M.; Jäger, Wolfgang

    2015-06-01

    Clusters of carboxylic acids with water, sulfuric acid, and other atmospheric species potentially increase the rate of new particle formation in the troposphere. Here, we present high-resolution pure rotational spectra of o-toluic acid and its complex with water in the range of 5-14 GHz, measured with a cavity-based molecular beam Fourier-transform microwave spectrometer. In both the monomer and the complex, the carboxylic acid functional group adopts a syn- conformation, with the acidic proton oriented away from the aromatic ring. In the complex, water participates in two hydrogen bonds, forming a six-membered intermolecular ring. Despite its large calculated c-dipole moment, no c-type transitions were observed for the complex, because of a large amplitude "wagging" motion of the unbound hydrogen of water, similar to the case of the benzoic acid-water complex. No methyl internal rotation splittings were observed, consistent with a high barrier (7 kJ mol-1) calculated for the monomer at the B3LYP/6-311++G(d,p) level of theory. Using statistical thermodynamics, experimental rotational constants were combined with a theoretical frequency analysis and binding energy to give an estimate of the percentage of hydrated acid in the atmosphere under various conditions. F. Riccobono, et al., Science, 344, 717 (2014). R. Zhang, et al., Science, 304, 1487 (2004). E. G. Schnitzler and W. Jäger, Phys. Chem. Chem. Phys., 16, 2305 (2014).

  7. Self-association of oxime: electronic and vibrational structures of formaldoxime monomer, dimer, and trimer

    Science.gov (United States)

    Akagi, Kazuo; Tanabe, Yukitoshi; Yamabe, Tokio

    1983-10-01

    The self-association of oxime is investigated from the aspect of intermolecular hydrogen bonding through ab initio SCF MO calculations on formaldoxime monomer, dimer, and trimer. It is understood from population analysis that formaldoxime monomer has inherently a suitable electronic distribution for constructing OH⋯3N hydrogen-bonded cyclic dimer and trimer. The formaldoxime trimer is characterized as the depressed nine membered ring. It is also confirmed to be more stable and preferable as a predominantly existing species than the dimer, which accounts for the experimental value of average association number for oximes. Vibrational analysis reveals that upon the self-association the OH stretching vibration is red-shifted, while both the OH in-plane and out-of-plane bending ones are blue-shifted, the results of which lead to a global feature of motion that ring wagging and ring puckering are activated. Largely enhanced intensities of IR-active OH stretching vibrations are well rationalized with more prominent charge polarization centered around =NOH sites in the formaldoxime dimer and trimer.

  8. Genomic redistribution of GR monomers and dimers mediates transcriptional response to exogenous glucocorticoid in vivo.

    Science.gov (United States)

    Lim, Hee-Woong; Uhlenhaut, N Henriette; Rauch, Alexander; Weiner, Juliane; Hübner, Sabine; Hübner, Norbert; Won, Kyoung-Jae; Lazar, Mitchell A; Tuckermann, Jan; Steger, David J

    2015-06-01

    Glucocorticoids (GCs) are commonly prescribed drugs, but their anti-inflammatory benefits are mitigated by metabolic side effects. Their transcriptional effects, including tissue-specific gene activation and repression, are mediated by the glucocorticoid receptor (GR), which is known to bind as a homodimer to a palindromic DNA sequence. Using ChIP-exo in mouse liver under endogenous corticosterone exposure, we report here that monomeric GR interaction with a half-site motif is more prevalent than homodimer binding. Monomers colocalize with lineage-determining transcription factors in both liver and primary macrophages, and the GR half-site motif drives transcription, suggesting that monomeric binding is fundamental to GR's tissue-specific functions. In response to exogenous GC in vivo, GR dimers assemble on chromatin near ligand-activated genes, concomitant with monomer evacuation of sites near repressed genes. Thus, pharmacological GCs mediate gene expression by favoring GR homodimer occupancy at classic palindromic sites at the expense of monomeric binding. The findings have important implications for improving therapies that target GR.

  9. Final report of the safety assessment of methacrylate ester monomers used in nail enhancement products.

    Science.gov (United States)

    2005-01-01

    Methacrylate ester monomers are used in as artificial nail builders in nail enhancement products. They undergo rapid polymerization to form a hard material on the nail that is then shaped. While Ethyl Methacrylate is the primary monomer used in nail enhancement products, other methacrylate esters are also used. This safety assessment addresses 22 other methacrylate esters reported by industry to be present in small percentages as artificial nail builders in cosmetic products. They function to speed up polymerization and/or form cross-links. Only Tetrahydrofurfuryl Methacrylate was reported to the FDA to be in current use. The polymerization rates of these methacrylate esters are within the same range as Ethyl Methacrylate. While data are not available on all of these methacrylate esters, the available data demonstrated little acute oral, dermal, or i.p. toxicity. In a 28-day inhalation study on rats, Butyl Methacrylate caused upper airway irritation; the NOAEL was 1801 mg/m3. In a 28-day oral toxicity study on rats, t-Butyl Methacrylate had a NOAEL of 20 mg/kg/day. Beagle dogs dosed with 0.2 to 2.0 g/kg/day of C12 to C18 methacrylate monomers for 13 weeks exhibited effects only in the highest dose group: weight loss, emesis, diarrhea, mucoid feces, or salivation were observed. Butyl Methacrylate (0.1 M) and Isobutyl Methacrylate (0.1 M) are mildly irritating to the rabbit eye. HEMA is corrosive when instilled in the rabbit eye, while PEG-4 Dimethacrylate and Trimethylolpropane Trimethacrylate are minimally irritating to the eye. Dermal irritation caused by methacrylates is documented in guinea pigs and rabbits. In guinea pigs, HEMA, Isopropylidenediphenyl Bisglycidyl Methacrylate, Lauryl Methacrylate, and Trimethylolpropane Trimethacrylate are strong sensitizers; Butyl Methacrylate, Cyclohexyl Methacrylate, Hexyl Methacrylate, and Urethane Methacrylate are moderate sensitizers; Hydroxypropyl Methacrylate is a weak sensitizer; and PEG-4 Dimethacrylate and

  10. Detection and quantification of monomers in unstimulated whole saliva after treatment with resin-based composite fillings in vivo.

    Science.gov (United States)

    Michelsen, Vibeke B; Kopperud, Hilde B M; Lygre, Gunvor B; Björkman, Lars; Jensen, Einar; Kleven, Inger S; Svahn, Johanna; Lygre, Henning

    2012-02-01

    Resin-based dental restorative materials contain allergenic methacrylate monomers, which may be released into saliva after restorative treatment. Monomers from resin-based composite materials have been demonstrated in saliva in vitro; however, studies analyzing saliva after restorative therapy are scarce. The aim of this study was to quantify methacrylate monomers in saliva after treatment with a resin-based composite filling material. Saliva was collected from 10 patients at four start points--before treatment, and 10 min, 24 h, and 7 d after treatment--and analysed by combined chromatography/mass spectrometry. The monomers bisphenol-A diglycidyl methacrylate (Bis-GMA), 2-hydroxyethyl methacrylate (HEMA), and urethane dimethacrylate (UDMA) were detected and quantified in the samples collected shortly (10 min) after treatment. The amounts detected ranged from 0.028 to 9.65 μg ml(-1) for Bis-GMA, from 0.015 to 0.19 μg ml(-1) for HEMA, and from 0.004 to 1.2 μg ml(-1) for UDMA. Triethyleneglycol dimethacrylate (TEGDMA) was detected in four of the samples. Ethoxylated bisphenol-A dimethacrylate (Bis-EMA) was not detected. Monomers were not detected in saliva samples collected before treatment, or 24 h or 7 d after treatment, with the exception of one sample, 24 h after treatment, in which HEMA was detected. In conclusion, monomers from the investigated resin-based composite and adhesive system were present in saliva shortly after treatment. One week after treatment, no monomers could be detected in patients' saliva samples.

  11. Molecular Design, Graft Polymerization and Performance Evaluation of Radiation Curable Flame Retardant Monomers Derived from Phosphorus-Nitrogen Systems

    Science.gov (United States)

    Edwards, Brian Tyndall

    The textile industry is constantly seeking new technologies to make its production more efficient, economical and environmentally friendly. An exciting new strategy to impart value-added functional finishes to textiles is the use of radiation, such as ultraviolet (UV) light, to drive the polymerization of monomers onto the surface of the substrates. These grafted polymeric layers provide the fiber or fabric with interesting new properties, such as antimicrobial behavior, water and oil repellency or flame retardancy. With the aid of a photoinitiator, UV curing can take place very rapidly and the process is waterless and uses less energy than traditional textile wet processing. With these thoughts in mind, this research explores the molecular design, synthesis, UV induced graft polymerization and performance evaluation of nine phosphorus-based flame retardant monomers for cellulosic cotton substrates. All monomers in this work were easily prepared using one-pot reactions procedures. With the assistance of Irgacure 819 photoinitiator, seven of the nine monomers were shown to simultaneously graft and polymerize onto the surface of cotton fabrics under UV radiation. JMPRTM Pro 10 software was used to explore the effect of variables, such as monomer concentration, photoinitiator concentration and UV exposure time, on the yield of the grafted polymeric layer. Burn testing of the treated fabrics in the vertical, 45° and horizontal orientations showed that all nine monomers were effective flame retardants that function via the condensed phase mechanism by encouraging the formation of nonflammable char. These burn test results were validated by thermogravimetric analysis, which demonstrated quantitatively that all nine monomers strongly promote the generation of a protective char. Finally, scanning electron microscopy was used to examine the surface morphology of the treated fabrics and visualize the grafted polymeric layer.

  12. Evaluating historical candidate genes for schizophrenia

    DEFF Research Database (Denmark)

    Farrell, M S; Werge, T; Sklar, P

    2015-01-01

    Prior to the genome-wide association era, candidate gene studies were a major approach in schizophrenia genetics. In this invited review, we consider the current status of 25 historical candidate genes for schizophrenia (for example, COMT, DISC1, DTNBP1 and NRG1). The initial study for 24 of thes...

  13. 40 CFR 307.21 - Nature of eligible claims.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 27 2010-07-01 2010-07-01 false Nature of eligible claims. 307.21... Nature of eligible claims. (a) Claims may be asserted against the Fund for necessary costs incurred for... nature, differing materially from those ordinarily encountered and generally recognized as inherent...

  14. 7 CFR 1751.102 - Modernization Plan Developer; eligibility.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 11 2010-01-01 2010-01-01 false Modernization Plan Developer; eligibility. 1751.102 Section 1751.102 Agriculture Regulations of the Department of Agriculture (Continued) RURAL UTILITIES... State Telecommunications Modernization Plan § 1751.102 Modernization Plan Developer; eligibility....

  15. 13 CFR 127.400 - What is an eligibility examination?

    Science.gov (United States)

    2010-01-01

    ... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false What is an eligibility examination? 127.400 Section 127.400 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION WOMEN-OWNED SMALL BUSINESS FEDERAL CONTRACT ASSISTANCE PROCEDURES Eligibility Examinations § 127.400 What is an...

  16. 49 CFR 37.125 - ADA paratransit eligibility: Process.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 1 2010-10-01 2010-10-01 false ADA paratransit eligibility: Process. 37.125... INDIVIDUALS WITH DISABILITIES (ADA) Paratransit as a Complement to Fixed Route Service § 37.125 ADA paratransit eligibility: Process. Each public entity required to provide complementary paratransit service...

  17. 49 CFR 37.123 - ADA paratransit eligibility: Standards.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 1 2010-10-01 2010-10-01 false ADA paratransit eligibility: Standards. 37.123... INDIVIDUALS WITH DISABILITIES (ADA) Paratransit as a Complement to Fixed Route Service § 37.123 ADA paratransit eligibility: Standards. (a) Public entities required by § 37.121 of this subpart to...

  18. 5 CFR 870.701 - Eligibility for life insurance.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Eligibility for life insurance. 870.701... REGULATIONS (CONTINUED) FEDERAL EMPLOYEES' GROUP LIFE INSURANCE PROGRAM Annuitants and Compensationers § 870.701 Eligibility for life insurance. (a) When an insured employee retires, Basic life insurance...

  19. 14 CFR 152.109 - Project eligibility: Airport planning.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Project eligibility: Airport planning. 152....109 Project eligibility: Airport planning. (a) Airport master planning. A proposed project for airport master planning is not approved unless— (1) The location of the existing or proposed airport is included...

  20. 42 CFR 433.148 - Denial or termination of eligibility.

    Science.gov (United States)

    2010-10-01

    ... Assignment of Rights to Benefits § 433.148 Denial or termination of eligibility. In administering the assignment of rights provision, the agency must: (a) Deny or terminate eligibility for any applicant or recipient who— (1) Refuses to assign his own rights or those of any other individual for whom he can...

  1. 38 CFR 21.47 - Eligibility for employment assistance.

    Science.gov (United States)

    2010-07-01

    ...) Providing employment services to veterans eligible for a rehabilitation program under chapter 31. Each... otherwise currently eligible for and entitled to participate in a program of rehabilitation under chapter 31... vocational rehabilitation program or a similar program under the Rehabilitation Act of 1973, as amended....

  2. 20 CFR 638.400 - Eligibility for participation.

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Eligibility for participation. 638.400... Placements in the Job Corps § 638.400 Eligibility for participation. To participate in the Job Corps, a young... citizen, United States national, a lawfully admitted permanent resident alien, a lawfully admitted...

  3. 42 CFR 407.10 - Eligibility to enroll.

    Science.gov (United States)

    2010-10-01

    ... SUPPLEMENTARY MEDICAL INSURANCE (SMI) ENROLLMENT AND ENTITLEMENT Individual Enrollment and Entitlement for SMI... individual is eligible to enroll for SMI if he or she— (1) Is entitled to hospital insurance under any of the.... An individual is not eligible to enroll for SMI if he or she has been convicted of— (1)...

  4. 40 CFR 35.535 - Activities eligible for funding.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Activities eligible for funding. 35.535... § 35.535 Activities eligible for funding. (a) Delegated, approved, or authorized activities. A Tribe or... approved for funding that the applicant now proposes to move into a Performance Partnership Grant,...

  5. 45 CFR 1308.12 - Eligibility criteria: Orthopedic impairment.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false Eligibility criteria: Orthopedic impairment. 1308... DISABILITIES Health Services Performance Standards § 1308.12 Eligibility criteria: Orthopedic impairment. (a) A child is classified as having an orthopedic impairment if the condition is severe enough to...

  6. 8 CFR 1208.13 - Establishing asylum eligibility.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Establishing asylum eligibility. 1208.13... IMMIGRATION REGULATIONS PROCEDURES FOR ASYLUM AND WITHHOLDING OF REMOVAL Asylum and Withholding of Removal § 1208.13 Establishing asylum eligibility. (a) Burden of proof. The burden of proof is on the...

  7. 8 CFR 208.13 - Establishing asylum eligibility.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Establishing asylum eligibility. 208.13... FOR ASYLUM AND WITHHOLDING OF REMOVAL Asylum and Withholding of Removal § 208.13 Establishing asylum eligibility. (a) Burden of proof. The burden of proof is on the applicant for asylum to establish that he...

  8. 34 CFR 303.4 - Limitation on eligible children.

    Science.gov (United States)

    2010-07-01

    ... 34 Education 2 2010-07-01 2010-07-01 false Limitation on eligible children. 303.4 Section 303.4 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF SPECIAL EDUCATION... eligible children. This part 303 does not apply to any child with disabilities receiving a free appropriate...

  9. 34 CFR 200.91 - SEA counts of eligible children.

    Science.gov (United States)

    2010-07-01

    ... 34 Education 1 2010-07-01 2010-07-01 false SEA counts of eligible children. 200.91 Section 200.91... Prevention and Intervention Programs for Children and Youth Who are Neglected, Delinquent, or At-Risk of Dropping Out § 200.91 SEA counts of eligible children. To receive an allocation under part D, subpart 1 of...

  10. 14 CFR 437.5 - Eligibility for an experimental permit.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Eligibility for an experimental permit. 437... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING EXPERIMENTAL PERMITS General Information § 437.5 Eligibility for an experimental permit. The FAA will issue an experimental permit to a person to launch...

  11. 12 CFR 1806.200 - Community eligibility and designation.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 7 2010-01-01 2010-01-01 false Community eligibility and designation. 1806.200 Section 1806.200 Banks and Banking COMMUNITY DEVELOPMENT FINANCIAL INSTITUTIONS FUND, DEPARTMENT OF THE TREASURY BANK ENTERPRISE AWARD PROGRAM Awards § 1806.200 Community eligibility and designation. (a)...

  12. 42 CFR 431.980 - Eligibility review procedures.

    Science.gov (United States)

    2010-10-01

    ....980 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES... Estimating Improper Payments in Medicaid and CHIP § 431.980 Eligibility review procedures. (a) Active case reviews. The agency must verify eligibility for all selected active cases for Medicaid and CHIP for the...

  13. 45 CFR 233.22 - Determining eligibility under prospective budgeting.

    Science.gov (United States)

    2010-10-01

    ... SERVICES COVERAGE AND CONDITIONS OF ELIGIBILITY IN FINANCIAL ASSISTANCE PROGRAMS § 233.22 Determining... 45 Public Welfare 2 2010-10-01 2010-10-01 false Determining eligibility under prospective budgeting. 233.22 Section 233.22 Public Welfare Regulations Relating to Public Welfare OFFICE OF FAMILY...

  14. 45 CFR 1611.4 - Financial eligibility for legal assistance.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false Financial eligibility for legal assistance. 1611.4 Section 1611.4 Public Welfare Regulations Relating to Public Welfare (Continued) LEGAL SERVICES... permissible under applicable law and regulation. (b) Consistent with the recipient's financial eligibility...

  15. 45 CFR 1611.8 - Change in financial eligibility status.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false Change in financial eligibility status. 1611.8 Section 1611.8 Public Welfare Regulations Relating to Public Welfare (Continued) LEGAL SERVICES... determination of financial eligibility and accepting a client for service, the recipient becomes aware that a...

  16. 22 CFR 228.23 - Eligibility of marine insurance.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Eligibility of marine insurance. 228.23 Section 228.23 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT RULES ON SOURCE, ORIGIN AND NATIONALITY FOR COMMODITIES AND SERVICES FINANCED BY USAID Conditions Governing the Eligibility of Commodity-Related Services for USAID Financing § 228.23...

  17. 24 CFR 1003.201 - Basic eligible activities.

    Science.gov (United States)

    2010-04-01

    ... equipment for use as part of a solid waste facility is eligible. In addition, the purchase of fire... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Basic eligible activities. 1003.201 Section 1003.201 Housing and Urban Development Regulations Relating to Housing and Urban Development...

  18. 13 CFR 301.1 - Overview of eligibility requirements.

    Science.gov (United States)

    2010-01-01

    ... sources of funding for the Project must fulfill the Investment Rate and Matching Share requirements set..., DEPARTMENT OF COMMERCE ELIGIBILITY, INVESTMENT RATE AND PROPOSAL AND APPLICATION REQUIREMENTS General § 301.1 Overview of eligibility requirements. In order to receive EDA Investment Assistance, an applicant and...

  19. 24 CFR 891.575 - Leasing to eligible families.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Leasing to eligible families. 891.575 Section 891.575 Housing and Urban Development Regulations Relating to Housing and Urban... Handicapped-Section 8 Assistance § 891.575 Leasing to eligible families. (a) Availability of assisted...

  20. 24 CFR 883.605 - Leasing to eligible families.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Leasing to eligible families. 883.605 Section 883.605 Housing and Urban Development Regulations Relating to Housing and Urban... Housing Assistance Payments Contract § 883.605 Leasing to eligible families. The provisions of 24 CFR...

  1. 24 CFR 880.504 - Leasing to eligible families.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Leasing to eligible families. 880.504 Section 880.504 Housing and Urban Development Regulations Relating to Housing and Urban... Housing Assistance Payments Contract § 880.504 Leasing to eligible families. (a) Availability of units...

  2. 24 CFR 891.720 - Leasing to eligible families.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Leasing to eligible families. 891.720 Section 891.720 Housing and Urban Development Regulations Relating to Housing and Urban... Handicapped Families and Individuals-Section 162 Assistance § 891.720 Leasing to eligible families....

  3. 9 CFR 51.23 - Eligibility for indemnity.

    Science.gov (United States)

    2010-01-01

    ... BRUCELLOSIS Indemnity for Sheep, Goats, and Horses § 51.23 Eligibility for indemnity. Owners of animals destroyed because of brucellosis are eligible to receive Federal indemnity for their animals if the animals are: (a) Sheep and goats in an affected herd or flock; (b) Sheep and goats that were obtained from...

  4. 9 CFR 54.3 - Animals eligible for indemnity payments.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Animals eligible for indemnity payments. 54.3 Section 54.3 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE... SCRAPIE Scrapie Indemnification Program § 54.3 Animals eligible for indemnity payments. (a) Indemnity...

  5. 45 CFR 1308.16 - Eligibility criteria: Traumatic brain injury.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false Eligibility criteria: Traumatic brain injury. 1308... DISABILITIES Health Services Performance Standards § 1308.16 Eligibility criteria: Traumatic brain injury. A child is classified as having traumatic brain injury whose brain injuries are caused by an...

  6. 49 CFR 639.17 - Eligible lease costs.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 7 2010-10-01 2010-10-01 false Eligible lease costs. 639.17 Section 639.17 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL TRANSIT ADMINISTRATION, DEPARTMENT OF TRANSPORTATION CAPITAL LEASES Requirements § 639.17 Eligible lease costs. (a) All...

  7. Health Care Coverage among Child Support-Eligible Children.

    Science.gov (United States)

    Aron, Laudan Y.

    Using data from the National Survey of America's Families (a nationally representative survey of the economic, social, and health characteristics of children, adults, and their families), this paper discusses health care coverage among child support eligible children. It begins with a detailed profile of child support eligible children living with…

  8. 7 CFR 1427.165 - Eligible seed cotton.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Eligible seed cotton. 1427.165 Section 1427.165... OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS COTTON Recourse Seed Cotton Loans § 1427.165 Eligible seed cotton. (a) Seed cotton pledged as collateral for a loan must be tendered to CCC by...

  9. 28 CFR 2.2 - Eligibility for parole; adult sentences.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Eligibility for parole; adult sentences. 2.2 Section 2.2 Judicial Administration DEPARTMENT OF JUSTICE PAROLE, RELEASE, SUPERVISION AND... § 2.2 Eligibility for parole; adult sentences. (a) A Federal prisoner serving a maximum term or...

  10. 45 CFR 1626.5 - Alien status and eligibility.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false Alien status and eligibility. 1626.5 Section 1626... RESTRICTIONS ON LEGAL ASSISTANCE TO ALIENS § 1626.5 Alien status and eligibility. Subject to all other... may provide legal assistance to an alien who is present in the United States and who is within one...

  11. 47 CFR 90.115 - Foreign government and alien eligibility.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Foreign government and alien eligibility. 90... government and alien eligibility. (a) No station authorization in the radio services governed by this part....9(c) of this chapter) if such entity is: (1) An alien or the representative of any alien; (2)...

  12. 48 CFR 919.7007 - Eligibility to be a Protege.

    Science.gov (United States)

    2010-10-01

    ... Protege. 919.7007 Section 919.7007 Federal Acquisition Regulations System DEPARTMENT OF ENERGY SOCIOECONOMIC PROGRAMS SMALL BUSINESS PROGRAMS The Department of Energy Mentor-Protege Program 919.7007 Eligibility to be a Protege. (a) To be eligible for selection as a Protege, a firm must: (1) Be a...

  13. 48 CFR 919.7005 - Eligibility to be a Mentor.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Eligibility to be a Mentor. 919.7005 Section 919.7005 Federal Acquisition Regulations System DEPARTMENT OF ENERGY SOCIOECONOMIC PROGRAMS SMALL BUSINESS PROGRAMS The Department of Energy Mentor-Protege Program 919.7005 Eligibility to...

  14. 5 CFR 870.1101 - Eligibility for a Living Benefit.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Eligibility for a Living Benefit. 870.1101 Section 870.1101 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT (CONTINUED) CIVIL SERVICE REGULATIONS (CONTINUED) FEDERAL EMPLOYEES' GROUP LIFE INSURANCE PROGRAM Living Benefits § 870.1101 Eligibility for a Living Benefit. (a)...

  15. A Method for Determining the Probability of Special Education Eligibility.

    Science.gov (United States)

    Braden, Jeffrey P.; Algina, James

    1989-01-01

    Proposes new method for calculating probability that student meets eligibility criteria for special education which avoids the distortion of dichotomous classification, uses multiple sources and measurement error in a meaningful manner, and promotes the accurate use of test data in eligibility decisions. (Author/NB)

  16. 24 CFR 3288.15 - Eligibility for dispute resolution.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Eligibility for dispute resolution... HOUSING AND URBAN DEVELOPMENT MANUFACTURED HOME DISPUTE RESOLUTION PROGRAM HUD Manufactured Home Dispute Resolution Program in HUD-Administered States § 3288.15 Eligibility for dispute resolution. (a) Initiation...

  17. 14 CFR 61.153 - Eligibility requirements: General.

    Science.gov (United States)

    2010-01-01

    ... (CONTINUED) AIRMEN CERTIFICATION: PILOTS, FLIGHT INSTRUCTORS, AND GROUND INSTRUCTORS Airline Transport Pilots § 61.153 Eligibility requirements: General. To be eligible for an airline transport pilot certificate... rating issued under this part; (2) Meet the military experience requirements under § 61.73 of this...

  18. 38 CFR 21.7550 - Ending dates of eligibility.

    Science.gov (United States)

    2010-07-01

    ... characterized by the Secretary of the military department concerned. The expiration of such a reservist's period... characterized by the Secretary of the military department concerned. The expiration of such a reservist's period... Reserve Eligibility § 21.7550 Ending dates of eligibility. (a) Time limit on eligibility—(1)...

  19. 40 CFR 310.5 - Am I eligible for reimbursement?

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 27 2010-07-01 2010-07-01 false Am I eligible for reimbursement? 310.5 Section 310.5 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SUPERFUND, EMERGENCY... HAZARDOUS SUBSTANCE RELEASES Provisions Who Can Be Reimbursed? § 310.5 Am I eligible for reimbursement? If...

  20. 49 CFR 639.13 - Eligible types of leases.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 7 2010-10-01 2010-10-01 false Eligible types of leases. 639.13 Section 639.13..., DEPARTMENT OF TRANSPORTATION CAPITAL LEASES Requirements § 639.13 Eligible types of leases. (a) General. Any... classification of the leasing arrangement for tax purposes. (b) Special circumstances. A recipient may...