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Sample records for shaw s4 substitution

  1. Shaw on Hamlet

    Science.gov (United States)

    Dukore, Bernard F.

    1971-01-01

    Shaw's preoccupation with Hamlet resonates in his creative writing. Article documents this statement not only by examining his novels and plays but by searching through prefaces, postscripts, reviews, letters, speeches, etc. that span Shaw's lifetime. (Author/RB)

  2. Structure health assessment and warning system (SHAWS)

    Science.gov (United States)

    Bock, Daniel M.; Kim, Keehoon; Mapar, Jalal

    2008-03-01

    We are developing a Structure Health Assessment and Warning System (SHAWS) based on building displacement measurements and wireless communication. SHAWS will measure and predict the stability/instability of a building, determine whether it is safe for emergency responders to enter during an emergency, and provide individual warnings on the condition of the structure. SHAWS incorporates remote sensing nodes (RSNs) installed on the exterior frame of a building. Each RSN includes a temperature sensor, a three-axis accelerometer making static-acceleration measurements, and a ZigBee wireless system (IEEE 802.15.4). The RSNs will be deployed remotely using an air cannon delivery system, with each RSN having an innovative adhesive structure for fast (<10 min) and strong installation under emergency conditions. Once the building has moved past a threshold (~0.25 in./building story), a warning will be issued to emergency responders. In addition to the RSNs, SHAWS will include a base station located on an emergency responder's primary vehicle, a PDA for mobile data display to guide responders, and individual warning modules that can be worn by each responder. The individual warning modules will include visual and audio indicators with a ZigBee receiver to provide the proper degree of warning to each responder.

  3. [Synthesis and biological activity of 1,4-benzoquinone-guanylhydrazone-thiosemicarbazone analogs. 1. Substitution at the S atom].

    Science.gov (United States)

    Schulze, W; Gutsche, W; Wohlrabe, K; Fleck, W; Tresselt, D

    1985-08-01

    The synthesis of S-substituted derivatives of 1,4-benzoquinone-guanylhydrazone-thiosemicarbazone is described. The obtained 1,4-benzoquinone-guanylhydrazone-S-alkyl (resp. aralkyl)-isothiosemicarbazones, in comparison with the unsubstituted standard compound, showed a significantly decreased biological activity against the murine leukemias L 1210 and P 388 as well as against the growth of several kinds of bacteria. Therefore the S-substitution seems not to be useful for reaching a maximum activity.

  4. Shaw's Comedy, Language Arts: 5113.90.

    Science.gov (United States)

    Dade County Public Schools, Miami, FL.

    This guide provides the teacher with strategies to aid students in examining five representative plays by Bernard Shaw and in comparing his comedy with the comic art of Oscar Wilde, Richard Sheridan, Ben Jonson, and William Shakespeare. Performance objectives include isolating elements which pertain to the life and times of Shaw, delineating…

  5. Shaw Air Force Base Capital Improvement Program Environmental Assessment

    Science.gov (United States)

    2010-05-01

    A FB Capital Im provem ent Program Environm ental A ssessm ent 3-21 Figure 3.6-1. W ater R esources at Shaw A FB under the Proposed A ction...Figure 3.6-2. W ater R esources at Shaw A FB under A lternative 1 0 Key c::::J Shaw!IFB C’l1 Proposed Project ~ Number -- Creek/Stream c:::::J w

  6. Henri Bergson y George Bernard Shaw: hábito, vida, muerte

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    Álvaro Cortina Urdampilleta

    2015-01-01

    Full Text Available Este artículo indaga en algunos aspectos de la antropología filosófica expuesta en la obra del francés Henri Bergson. Para ello, nos serviremos de la confrontación de su doctrina original con la de un bergsoniano sui generis, el intelectual y dramaturgo irlandés George Bernard Shaw. El Prefacio. A medio siglo infiel, de Shaw, incluido en su obra más ambiciosa, Vuelta a Matusalén. Un Pentateuco Metabiológico, de 1921, será el texto base con el que haremos dialogar a Bergson con este periférico bergsonismo. Tomaremos como hilo conductor la teoría sobre el hábito, en el contexto de la metafísica de la evolución de los seres orgánicos, y lo llevaremos hasta el concepto límite, que parece conciliar ambas posturas: la idea de muerte superable. Ni en Bergson ni en Shaw los hábitos (la Cultura forman parte integral de la esencia del hombre, y la muerte (cuestión en la que Bergson es mucho más elusivo juega en ellos un rol anfibio, entre Cultura y Naturaleza.

  7. The ethics of killing human/great-ape chimeras for their organs: a reply to Shaw et al.

    Science.gov (United States)

    Palacios-González, César

    2016-06-01

    The aim of this paper is to critically examine David Shaw, Wybo Dondorp, and Guido de Wert's arguments in favour of the procurement of human organs from human/nonhuman-primate chimeras, specifically from great-ape/human chimeras. My main claim is that their arguments fail and are in need of substantial revision. To prove this I first introduce the topic, and then reconstruct Shaw et al.'s position and arguments. Next, I show that Shaw et al.: (1) failed to properly apply the subsidiarity and proportionality principles; (2) neglected species overlapping cases in their ethical assessment; (3) ignored the ethics literature on borderline persons; and (4) misunderstood McMahan's two-tiered moral theory. These mistakes render an important part of their conclusions either false or problematic to the point that they would no longer endorse them. Finally I will briefly mention a possible multipolar solution to the human organ shortage problem that would reduce the need for chimeras' organs.

  8. Influence of SrO substitution for CaO on the properties of bioactive glass S53P4.

    Science.gov (United States)

    Massera, Jonathan; Hupa, Leena

    2014-03-01

    Commercial melt-quenched bioactive glasses consist of the oxides of silicon, phosphorus, calcium and sodium. Doping of the glasses with oxides of some other elements is known to affect their capability to support hydroxyapatite formation and thus bone tissue healing but also to modify their high temperature processing parameters. In the present study, the influence of gradual substitution of SrO for CaO on the properties of the bioactive glass S53P4 was studied. Thermal analysis and hot stage microscopy were utilized to measure the thermal properties of the glasses. The in vitro bioactivity and solubility was measured by immersing the glasses in simulated body fluid for 6 h to 1 week. The formation of silica rich and hydroxyapatite layers was assessed from FTIR spectra analysis and SEM images of the glass surface. Increasing substitution of SrO for CaO decreased all characteristic temperatures and led to a slightly stronger glass network. The initial glass dissolution rate increased with SrO content. Hydroxyapatite layer was formed on all glasses but on the SrO containing glasses the layer was thinner and contained also strontium. The results suggest that substituting SrO for CaO in S53P4 glass retards the bioactivity. However, substitution greater than 10 mol% allow for precipitation of a strontium substituted hydroxyapatite layer.

  9. Prediction of Instability for Miscible Displacements in a Hele-Shaw Cell Prévision de l'instabilité pour des déplacements miscibles dans une cellule Hele-Shaw

    Directory of Open Access Journals (Sweden)

    Coskuner G.

    2006-11-01

    Full Text Available A universal dimensionless scaling group and its critical value at the onset of instability for a miscible displacement in a Hele-Shaw cell is derived. The derivation is based on a variational technique and it is capable of considering, for the first time, the effect of the length of a Hele-Shaw cell on the criterion for the onset of instability. The theory is verified by comparing it with forty-four Hele-Shaw cell experiments. On calcule un groupe universel sans dimension de mise à l'échelle et sa valeur critique au départ de l'instabilité dans un déplacement miscible dans une cellule Hele-Shaw. Ce calcul est basé sur une technique variationnelle et permet, pour la première fois, de prendre en compte l'effet de la longueur d'une cellule Hele-Shaw sur le critère d'apparition d'instabilité. La théorie est vérifiée en la comparant avec des expériences réalisées avec quarante-quatre cellules Hele-Shaw.

  10. Facile synthesis of some novel 2-substituted-4,6-diarylpyrimidines using 4 ' -hydroxy-3 ' ,5 ' -dinitrochalcones and S-benzylthiouronium chloride

    Directory of Open Access Journals (Sweden)

    K. L. Ameta

    2012-01-01

    Full Text Available Various 4'-hydroxy-3',5'-dinitro substituted chalcones 1 and S-benzylthiouronium chloride (SBT 2 in the presence of DMF-organic bases (morpholine/ pyrrolidine/ piperidine gave 4,6-diaryl-2-(4-morpholinyl / 1-pyrrolidinyl /1-piperidinyl- pyrimidines 4, 5 and 6 in a facile one-pot conversion. In an another attempt reactants 1 and 2 yielded intermediate 2-benzylthiopyrimidines 3, in presence of DMF, which on treatment with heterocyclic secondary amines gave products 4, 5 and 6 in an alternate two-step process.

  11. Multiple bubbles in a Hele-Shaw cell

    International Nuclear Information System (INIS)

    Vasconcelos, G.L.

    1994-01-01

    A new class of exact solutions is reported for an infinite stream of identical groups of bubbles moving with a constant velocity U in a Hele-Shaw cell when surface tension is neglected. It is suggested that the existence of these solutions might explain some of the complex behavior observed in recent experiments on rising bubbles in a Hele-Shaw cell. Solutions for a finite number of bubbles in a channel are also obtained. In this case, it is shown that solutions with an arbitrary bubble velocity U>V, where V is the fluid velocity at infinity, can in general be obtained from a simple transformation of the solutions for U=2V

  12. Ultrasound Promoted Synthesis of Bis(substituted pyrazol-4-ylcarbonyl-Substituted Thioureas

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    Li Xiao

    2009-03-01

    Full Text Available A series of novel bis(substituted pyrazol-4-ylcarbonyl-substituted thioureas have been synthesized by the reactions of substituted pyrazol-4-ylcarbonyl isothiocyanates with different diamines under ultrasound irradiation and classical heating method at 20-25 °C. In general, substantial improvement in rates and modest yields increases were observed when reactions were carried out under sonication, compared with the classical heating method. The structures of these compounds have been elucidated by elemental and spectral (IR, 1H-NMR analysis.

  13. New archeointensity results from the reconstructed ancient kiln by the Tsunakawa-Shaw method

    Science.gov (United States)

    Yamamoto, Y.; Hatakeyama, T.; Kitahara, Y.; Saito, T.

    2017-12-01

    Yamamoto et al. (2015) reported that baked clay samples from the floor of a reconstructed ancient kiln provided a reliable Tsunakawa-Shaw (LTD-DHT Shaw) archeointensity (AI) estimate of 47.3 +/- 2.2 microT which is fairly consistent with the in situ geomagnetic field of 46.4 microT at the time of the reconstruction. The reconstruction was conducted to reproduce an excavated kiln of the seventh century in Japan and Sue-type potteries of contemporary style were also fired (Nakajima et al., 1974). Two of the potteries with reddish color were recently subjected to the Tsunakawa-Shaw archeointensity determinations, resulting in reliable AI estimates of 45.4 +/- 2.3 (N=6) and 48.2 +/- 2.7 microT (N=15) when specimens were heated in air in laboratory (Yamamoto et al., 2017 JpGU-AGU Joint Meeting). We have had another opportunity to take samples from a new reconstructed ancient kiln in Japan which was fired in autumn 2016. The samples were two Sue-type potteries with grayish color (bowl-type and plate-type) and some blocks collected from inner wall of the kiln body. They were cut into mini specimens and then subjected to the Tsunakawa-Shaw experiment. Heating in laboratory was done either in air or vacuum.For the bowl-type pottery, AIs of 46.9 +/- 2.8 (N=6, air) and 45.3 +/- 2.3 microT (N=6, vacuum) are obtained. They are indistinguishable each other and consistent with the IGRF field of 47.4 microT at the reconstructed location in 2016. For the plate-type pottery, AIs result in 41.8 +/- 1.3 (N=4, air) and 43.9 +/- 3.9 microT (N=4, vacuum). They are also indistinguishable each other but the former AI is slightly lower than the IGRF field.For the inner wall, AIs of 45.0 (N=1, air) and 46.8 microT (N=1, vacuum) are obtained from a right-side wall, and those of 45.5 +/- 2.5 (N=2, air) and 47.7 +/- 3.0 microT (N=2, vacuum) are observed from a left-side wall. They are all indistinguishable and consistent with the IGRF field.

  14. Henry Selby Hele-Shaw LLD, DSc, EngD, FRS, WhSch (1854-1941: Engineer, inventor and educationist

    Directory of Open Access Journals (Sweden)

    Jane Carruthers

    2010-03-01

    Full Text Available H.S. Hele-Shaw (1854–1941 was one of the most outstanding engineering scientists of his generation and an eminent figure in engineering education during the late-19th and early-20th centuries. His work in hydrodynamics (the Hele-Shaw cell and Hele-Shaw pump and his important contribution to the successful development of high-speed aircraft (his variable pitch airscrew, continues to be relevant today. In 1922, as President of the Institution of Mechanical Engineers, he introduced the National Certificate scheme in Britain. It is not well known that Hele-Shaw spent two years in South Africa (1904–1905 attached to the Transvaal Technical Institute, a forerunner of the University of the Witwatersrand. One of only three Fellows of the Royal Society of London in southern Africa in 1905, he was a founder Council member of the Royal Society of South Africa and one of the hosts of the 1905 visit to southern Africa by the British Association for the Advancement of Science. The purpose of this paper is to highlight the time he spent in South Africa and to contextualise it within the larger perspective of his engineering career.

  15. Rotating Hele-Shaw cell with a time-dependent angular velocity

    Science.gov (United States)

    Anjos, Pedro H. A.; Alvarez, Victor M. M.; Dias, Eduardo O.; Miranda, José A.

    2017-12-01

    Despite the large number of existing studies of viscous flows in rotating Hele-Shaw cells, most investigations analyze rotational motion with a constant angular velocity, under vanishing Reynolds number conditions in which inertial effects can be neglected. In this work, we examine the linear and weakly nonlinear dynamics of the interface between two immiscible fluids in a rotating Hele-Shaw cell, considering the action of a time-dependent angular velocity, and taking into account the contribution of inertia. By using a generalized Darcy's law, we derive a second-order mode-coupling equation which describes the time evolution of the interfacial perturbation amplitudes. For arbitrary values of viscosity and density ratios, and for a range of values of a rotational Reynolds number, we investigate how the time-dependent angular velocity and inertia affect the important finger competition events that traditionally arise in rotating Hele-Shaw flows.

  16. Paleomagnetic intensity of Aso pyroclastic flows: Additional results with LTD-DHT Shaw method, Thellier method with pTRM-tail check

    Science.gov (United States)

    Maruuchi, T.; Shibuya, H.

    2009-12-01

    For the sake to calibrate the absolute value of the ’relative paleointensity variation curve’ drawn from sediment cores, Takai et al. (2002) proposed to use pyroclastic flows co-bearing with wide spread tephras. The pyroclastic flows prepare volcanic rocks with TRM, which let us determine absolute paleointensity, and the tephras prepare the correlation with sediment stratigraphy. While 4 out of 6 pyroclastic flows are consistent with Sint-800 paleointensity variation curve, two flows, Aso-2 and Aso-4, show weaker and stronger than Sint-800 beyond the error, respectively. We revisited the paleointensity study of Aso pyroclastic flows, adding LTD- DHT Shaw method, the pTRM-tail check in Thellier experiment, and LTD-DHT Shaw method by using volcanic glasses. We prepared 11 specimens from 3 sites of Aso-1 welded tuff for LTD-DHT Shaw method experiments, and obtained 6 paleointensities satisfied a set of strict criteria. They yield an average paleointensity of 21.3±5.8uT, which is smaller than 31.0±3.4uT provided by Takai et al. (2002). For Aso-2 welded tuff, 11 samples from 3 sites were submitted to Thellier experiments, and 6 passed a set of pretty stringent criteria including pTRM-tail check, which is not performed by Takai et al. (2002). They give an average paleointensity of 20.2±1.5uT, which is virtually identical to 20.2±1.0uT (27 samples) given by Takai et al. (2002). Although the success rate was not good in LTD-DHT Shaw method, 2 out of 12 specimens passed the criteria, and gave 25.8±3.4uT, which is consistent with Takai et al. (2002). In addition, we obtained a reliable paleointensity from a volcanic glass in LTD-DHT Shaw method, it gives a paleointensity of 23.6 uT. It is also consitent with Takai et al. (2002). For Aso-3 welded tuff, we performed only LTD-DHT Shaw method for one specimen from one site yet. It gives a paleointensity of 43.0uT, which is higher than 31.8±3.6uT given by Takai et al. (2002). Eight sites were set for Aso-4 welded tuff

  17. 40 CFR 721.10043 - Dineopentyl-4-substituted phthalate (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Dineopentyl-4-substituted phthalate... Specific Chemical Substances § 721.10043 Dineopentyl-4-substituted phthalate (generic). (a) Chemical... as dineopentyl-4-substituted phthalate (PMN P-02-697) is subject to reporting under this section for...

  18. Synthesis of 4-(2-substituted hydrazinyl)benzenesulfonamides and their carbonic anhydrase inhibitory effects.

    Science.gov (United States)

    Gul, Halise Inci; Kucukoglu, Kaan; Yamali, Cem; Bilginer, Sinan; Yuca, Hafize; Ozturk, Iknur; Taslimi, Parham; Gulcin, Ilhami; Supuran, Claudiu T

    2016-08-01

    In this study, 4-(2-substituted hydrazinyl)benzenesulfonamides were synthesized by microwave irradiation and their chemical structures were confirmed by (1)H NMR, (13)CNMR, and HRMS. Ketones used were: Acetophenone (S1), 4-methylacetophenone (S2), 4-chloroacetophenone (S3), 4-fluoroacetophenone (S4), 4-bromoacetophenone (S5), 4-methoxyacetophenone (S6), 4-nitroacetophenone (S7), 2-acetylthiophene (S8), 2-acetylfuran (S9), 1-indanone (S10), 2-indanone (S11). The compounds S9, S10 and S11 were reported for the first time, while S1-S8 was synthesized by different method than literature reported using microwave irradiation method instead of conventional heating in this study. The inhibitory effects of 4-(2-substituted hydrazinyl)benzenesulfonamide derivatives (S1-S11) against hCA I and II were studied. Cytosolic hCA I and II isoenzymes were potently inhibited by new synthesized sulphonamide derivatives with Kis in the range of 1.79 ± 0.22-2.73 ± 0.08 nM against hCA I and in the range of 1.72 ± 0.58-11.64 ± 5.21 nM against hCA II, respectively.

  19. Mössbauer spectral studies of Ti{sup 4+} substituted nickel ferrite

    Energy Technology Data Exchange (ETDEWEB)

    Kale, C.M., E-mail: cmk1973@rediffmail.com [Department of Physics, Indraraj Art, Commerce, and Science College, Sillod, Aurangabad (India); Bardapurkar, P.P. [S.N. Arts, D.J. Malpani Commerce and B.N. Sarda Science College, Sangamner (India); Shukla, S.J. [Department of Physics, P.G. Research Centre, Deogiri College, Aurangabad (India); Jadhav, K.M. [Department of Physics, Dr. Babasaheb Ambedkar Marathwada University, Aurangabad 431001, M.S. (India)

    2013-04-15

    Polycrystalline ferrites with general formula Ni{sub 1+x}Ti{sub x}Fe{sub 2−2x}O{sub 4}, where 0.0≤x≤0.7 were prepared through double sintering ceramic technique using A.R. grade oxides of respective ions. The phase purity of all the samples was checked by X-ray diffraction (XRD) technique. The X-ray diffraction pattern shows all reflections belonging to cubic spinel structure. No extra peak other than cubic spinel was observed in the X-ray diffraction pattern. Using XRD data, the lattice constant was calculated for all the compositions. The lattice constant decreases linearly with Ti{sup 4+} substitutions and obeys Vegard's law. The magnetic properties (saturation magnetization, magneton number, coercivity) were investigated using pulse field hysteresis loop technique at room temperature. The values of coercivity decreases with Ti{sup 4+} content increases. The saturation magnetization and magneton number both significantly decreases with increase in Ti{sup 4+} substitution. Mössbauer spectra of all the samples exhibit sextet. The Mössbauer parameters obtained from Mössbauer spectrum revealed the influence of titanium substitution. -- Highlights: ► XRD synthesis of Ti{sup 4+} substituted spinel structure. ► Non-magnetic Ti{sup 4+} substitution is much effective on magnetic properties. ► Mössbauer spectrum at room temperature influence on hyperfine field for both (A) and [B] sites. ► Zeeman pattern with small isomer shift exhibits small hyperfine field.

  20. Synthesis of 1-Substituted-4-(Pyridin-4-yl)

    African Journals Online (AJOL)

    Purpose: To synthesize a new series of 1-substituted-4-(pyridin-4-yl) [1,2,4] triazolo [4,3-a]quinazolin- 5(4H)-ones and evaluate them for H1-antihistaminic activity with negligible side effects in guinea pigs. Methods: The synthesized compounds were characterized by Infrared spectroscopy (IR), proton nuclear magnetic ...

  1. Computational modeling of the structure and the ionic conductivity of the solid electrolyte materials Li3AsS4 and its Ge substitutions

    Science.gov (United States)

    Al-Qawasmeh, Ahmad; Holzwarth, N. A. W.

    Oak Ridge National Laboratory (G. Sahu et al.) reported that the substitution of Ge into Li3AsS4 leads to the composition Li3.334Ge0.334As0.666S4 with impressively high ionic conductivity . We use ab initio calculations to examine the structural relationships and the ionic conductivity mechanisms for pure Li3AsS4, Li3.334Ge0.334As0.666S4, and other compositions of these electrolytes. Supported by NSF Grant DMR-1105485 and 1507942 and WFU's DEAC cluster.

  2. Hyperbolic prisms and foams in Hele-Shaw cells

    Energy Technology Data Exchange (ETDEWEB)

    Tufaile, A., E-mail: tufaile@usp.br [Soft Matter Laboratory, Escola de Artes, Ciencias e Humanidades, Universidade de Sao Paulo, 03828-000, Sao Paulo (Brazil); Tufaile, A.P.B. [Soft Matter Laboratory, Escola de Artes, Ciencias e Humanidades, Universidade de Sao Paulo, 03828-000, Sao Paulo (Brazil)

    2011-10-03

    The propagation of light in foams creates patterns which are generated due to the reflection and refraction of light. One of these patterns is observed by the formation of multiple mirror images inside liquid bridges in a layer of bubbles in a Hele-Shaw cell. We are presenting the existence of these patterns in foams and their relation with hyperbolic geometry and Sierpinski gaskets using the Poincare disk model. The images obtained from the experiment in foams are compared to the case of hyperbolic optical elements. -- Highlights: → The chaotic scattering of light in foams generating deltoid patterns is based on hyperbolic geometry. → The deltoid patterns are obtained through the Plateau borders in a Hele-Shaw cell. → The Plateau borders act like hyperbolic prism. → Some effects of the refraction and reflection of the light rays were studied using a hyperbolic prism.

  3. Non-Newtonian Hele-Shaw Flow and the Saffman-Taylor Instability

    International Nuclear Information System (INIS)

    Kondic, L.; Shelley, M.J.; Palffy-Muhoray, P.

    1998-01-01

    We explore the Saffman-Taylor instability of a gas bubble expanding into a shear thinning liquid in a radial Hele-Shaw cell. Using Darcy close-quote s law generalized for non-Newtonian fluids, we perform simulations of the full dynamical problem. The simulations show that shear thinning significantly influences the developing interfacial patterns. Shear thinning can suppress tip splitting, and produce fingers which oscillate during growth and shed side branches. Emergent length scales show reasonable agreement with a general linear stability analysis. copyright 1998 The American Physical Society

  4. Noval 1-substituted-3,5-dimethyl-4-[(substituted phenyl diazenyl] pyrazole derivatives: Synthesis and pharmacological activity

    Directory of Open Access Journals (Sweden)

    Sabir Hussain

    2015-05-01

    Full Text Available Several-1-carbothioamide-3,5-dimethyl-4-[(substituted phenyl diazenyl] pyrazoles 2a–d, 1-(pyridine-4-ylcarbonyl-3,5-dimethyl-4-[(substituted phenyl diazenyl] pyrazoles 3a–d, 1-(5-chloro-6-fluoro-1,3-benzothiazole-2-ylthiocarbamoyl-3,5-dimethyl-4-[(substituted phenyl diazenyl] pyrazoles 4a–d and 1-[(1,2,4-triazole-4-yl carbothioamide]-3,5-dimethyl-4-[(substituted phenyl diazenyl] pyrazoles 5a–d were synthesized. The structures of the newly synthesized compounds were supported by IR, 1H NMR and mass spectral data. These compounds were investigated for their, anti-inflammatory, analgesic, ulcerogenic, lipid peroxidation, antibacterial and antifungal activities. Some of the synthesized compounds showed potent anti-inflammatory activity along with minimal ulcerogenic effect and lipid peroxidation, compared to ibuprofen and flurbiprofen. Some of the tested compounds also showed moderate antimicrobial activity against tested bacterial and fungal strains.

  5. Ab initio calculations for the substitutions of Al(OH)4- and SO42- with Si tetrahedra

    International Nuclear Information System (INIS)

    Rahman, Md.Mazibur; Tanaka, Satoru; Nagasaki, Shinya

    2001-01-01

    We have studied the interaction phenomena for the substitutions of Al(OH) 4 - and SO 4 2- with both paired and bridging Si tetrahedra likely to be occurred in C-S-H gel coexisting with ettringite system. Gaussian 94 program has been used to obtain the total energy of the molecule in the optimized structure employing HF/3-21G level of theory. It has been investigated that the net charge on the substitution site causes the modification of the original structure during the substitution. The substitutions of Al(OH) 4 - with Si tetrahedra were found to be thermodynamically possible in both paired and bridging Si tetrahedra at chemical equilibrium. The substitutions of SO 4 2- with Si tetrahedra were found to be thermodynamically possible at the limited positions as well. It this work, these possibilities are also discussed with the estimated activated energies for the substitutions of Al(OH) 4 - and SO 4 2- with paired Si tetrahedra. (author)

  6. 4-Substituted boro-proline dipeptides: synthesis, characterization, and dipeptidyl peptidase IV, 8, and 9 activities.

    Science.gov (United States)

    Wu, Wengen; Liu, Yuxin; Milo, Lawrence J; Shu, Ying; Zhao, Peng; Li, Youhua; Woznica, Iwona; Yu, Gengli; Sanford, David G; Zhou, Yuhong; Poplawski, Sarah E; Connolly, Beth A; Sudmeier, James L; Bachovchin, William W; Lai, Jack H

    2012-09-01

    The boroProline-based dipeptidyl boronic acids were among the first DPP-IV inhibitors identified, and remain the most potent known. We introduced various substitutions at the 4-position of the boroProline ring regioselectively and stereoselectively, and incorporated these aminoboronic acids into a series of 4-substituted boroPro-based dipeptides. Among these dipeptidyl boronic acids, Arg-(4S)-boroHyp (4q) was the most potent inhibitor of DPP-IV, DPP8 and DPP9, while (4S)-Hyp-(4R)-boroHyp (4o) exhibited the most selectivity for DPP-IV over DPP8 and DPP9. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. Synthesis, Characterization and Antifungal Evaluation of 5-Substituted-4-Amino-1,2,4-Triazole-3-Thioesters

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    Aurangzeb Hasan

    2011-01-01

    Full Text Available A series of 5-substituted-4-amino-1,2,4-triazole-3-thioesters was synthesized by converting variously substituted organic acids successively into the corresponding esters, hydrazides, 5-substituted-1,3,4-oxadiazole-2-thiols, 5-substituted-1,2,4-triazole-2-thiols and 5-substituted-1,3,4-oxadiazole-2-thioesters. Finally the target compounds were obtained by refluxing 5-substituted-1,3,4-oxadiazole-2-thioesters in the presence of hydrazine hydrate and absolute alcohol. The structures of the synthesized compounds were established by physicochemical and spectroscopic methods. The synthesized compounds were evaluated for their in vitro antifungal activity. Some of the evaluated compounds possessed significant antifungal activity as compared to a terbinafine standard.

  8. Effect of the oxygen isoelectronic substitution in Cu2ZnSnS4 and its photovoltaic application

    International Nuclear Information System (INIS)

    Tablero, C.

    2012-01-01

    The optoelectronic properties of Cu 2 ZnSnS 4 and environmental considerations have attracted significant interest for photovoltaics. Using first-principles, we analyze the possible improvement of this material as a photovoltaic absorber via the isoelectronic substitution of S with O atoms. The evolution of the acceptor level is analyzed with respect to the atomic position of the nearest neighbors of the O atom. We estimate the maximum efficiency of this compound when used as a light absorber. The presence of the sub-band gap level below the conduction band could increases the solar-energy conversion with respect to the host. - Highlights: ► Cu 2 ZnSnS 4 is a promising material for low cost thin film solar cell technology. ► Its optoelectronic properties could be improved by states in the band gap. ► The oxygen to give rise to deep traps. ► Maximum efficiency can be larger than the host semiconductor.

  9. Analisis Isi Lambung Ikan Senangin (Eleutheronema tetradactylum Shaw di Perairan Dumai

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    Titrawani Titrawani

    2016-03-01

    Full Text Available The research about stomach content analysis of thraedfin fish (Eleutheronema tetradactylum Shaw “senangin fish” in Dumai aquatic was taken out on July until Maret 2011. The research aimed to know the kind of senangin fish’s food include main food, supplement food and additional food. The used analysis based on Natarjan and Jingran in Effendi (1979, by analysis index of preponderance (Higher Part Index. Based on them main food of senangin fish are  Crustacea,  Engraulidae and animal debric.

  10. MHD Hele-Shaw flow of Rivlin-Ericksen fluid

    International Nuclear Information System (INIS)

    Ghosh, B.C.; Sengupta, P.R.

    1995-01-01

    In this paper, an attempt has been made to study the MHD Hele-Shaw flow of Rivlin-Ericksen visco-elastic fluid assuming the pressure gradient to be proportional to exp (-nt). The velocity components are obtained and the effect of visco-elasticity is discussed on velocity components. (author). 8 refs

  11. Selective Se-for-S substitution in Cs-bearing uranyl compounds

    Energy Technology Data Exchange (ETDEWEB)

    Gurzhiy, Vladislav V., E-mail: vladgeo17@mail.ru [Department of Crystallography, St. Petersburg State University, University Emb. 7/9, 199034 St. Petersburg, Russia Federation (Russian Federation); Tyumentseva, Olga S.; Krivovichev, Sergey V. [Department of Crystallography, St. Petersburg State University, University Emb. 7/9, 199034 St. Petersburg, Russia Federation (Russian Federation); Tananaev, Ivan G. [Far Eastern Federal University, Suhanova st. 8, Vladivostok 690950 (Russian Federation)

    2017-04-15

    Phase formation in the mixed sulfate-selenate aqueous system of uranyl nitrate and cesium nitrate has been investigated. Two types of crystalline compounds have been obtained and characterized using a number of experimental (single crystal XRD, FTIR, SEM) and theoretical (information-based complexity calculations, topological analysis) techniques. No miscibility gaps have been observed for Cs{sub 2}[(UO{sub 2}){sub 2}(TO{sub 4}){sub 3}] (T= S, Se), which crystallizes in tetragonal system, P-42{sub 1}m, a =9.616(1)–9.856(2), c =8.105(1)–8.159(1) Å, V =749.6(2)–792.5(3) Å{sup 3}. Nine phases with variable amount of S and Se have been structurally characterized. The structures of the Cs{sub 2}[(UO{sub 2}){sub 2}(TO{sub 4}){sub 3}] (T= S, Se) compounds are based upon the [(UO{sub 2}){sub 2}(TO{sub 4}){sub 3}]{sup 2-} layers of corner-sharing uranyl pentagonal bipyramids and TO{sub 4} tetrahedra. The layers contain two types of tetrahedral sites: T1 (3-connected, i.e. having three O atoms shared by adjacent uranyl polyhedra) and T2 (4-connected). The Se-for-S substitution in tetrahedral sites is highly selective with smaller S{sup 6+} cation showing a strong preference for the more tightly bonded T2 site. Crystallization in the pure Se system starts with the formation of Cs{sub 2}[(UO{sub 2})(SeO{sub 4}){sub 2}(H{sub 2}O)](H{sub 2}O) crystals, its subsequent dissolution and formation of Cs{sub 2}[(UO{sub 2}){sub 2}(SeO{sub 4}){sub 3}]. The information-based structural complexity calculations for these two phases support the rule that more topologically complex structures form at the latest stages of crystallization. - Graphical abstract: Nine phases representing the Cs{sub 2}[(UO{sub 2}){sub 2}(TO{sub 4}){sub 3}] (T= S, Se) solid solution series with variable amount of S and Se have been prepared by isothermal evaporation from aqueous solutions and characterized using a number of experimental and theoretical techniques. No immiscibility is observed between the

  12. Substitution Effects and Linear Free Energy Relationships During Reduction of 4- Benzoyl-n-(4-substituted Benzyl)pyridinium Cations

    Science.gov (United States)

    Leventis, Nicholas; Zhang, Guo-Hui; Rawashdeh, Abdel-Monem M.; Sotiriou-Leventis, Chariklia; Gray, Hugh R. (Technical Monitor)

    2003-01-01

    In analogy to 4-(para-substituted benzoyl)-N-methylpyridinium cations (1-X's), the title species (2-X's, -X = -OCH3, -CH3, -H, -Br, -COCH3, -NO2) undergo two reversible, well-separated (E(sub 1/2) greater than or equal to 650 mV) one-electron reductions. The effect of substitution on the reduction potentials of 2-X's is much weaker than the effect of the same substituents on 1-X's: the Hammett rho-values are 0.80 and 0.93 for the 1st- and 2nd-e reduction of 2-X's vs. 2.3 and 3.3 for the same reductions of 1-X's, respectively. Importantly, the nitro group of 2-NO2 undergoes reduction before the 2nd-e reduction of the 4-benzoylpyridinium system. These results suggest that the redox potentials of the 4-benzoylpyridinium system can be course-tuned via p-benzoyl substitution and fine-tuned via para-benzyl substitution. Introducing the recently derived substituent constant of the -NO2(sup)- group (sigma para-NO2(sup)- = -0.97) yields an excellent correlation for the 3rd-e reduction of 2- NO2 (corresponding to the reduction of the carbonyl group) with the 2nd-e reduction of the other 2-X's, and confirms the electron donating properties of -NO2(sup)-.

  13. Preparation of novel trifluoroacetylketene O,N-acetals and trifluoromethyl-containing S,S-sulfoximido N-substituted heterocycles

    Energy Technology Data Exchange (ETDEWEB)

    Bonacorso, Helio G.; Vezzosi, Renata P.; Rodrigues, Isadora R.; Drekener, Roberta L.; Porte, Liliane M. F.; Flores, Alex F.C.; Zanatta, Nilo; Martins, Marcos A.P. [Universidade Federal de Santa Maria (UFSM), RS (Brazil). Dept. de Quimica], e-mail: heliogb@base.ufsm.br

    2009-07-01

    Two new trifluoroacetylketene O,N-acetals [CF{sub 3}C(O)CH=C(OEt)(NS(O)R{sub 2}), where R = CH{sub 3}, Ph] derived from the reaction of 4,4-diethoxy-1,1,1-trifluorobut-3-en-2-one [CF{sub 3}C(O) CH=C(OEt){sub 2}] with S,S-dimethyl- and S-methyl-S-phenyl-sulfoximide [HN=S(O)R{sub 2}], in the presence of triethylamine, have been obtained, in 60-72% yields, and applied in the synthesis of S,S-dimethylsulfoximido-substituted pyrazoles, isoxazoles and pyrimidines, in 55-89% yields, from the reactions of 4-ethoxy-4-(S,S-dimethylsulfoximido)-1,1,1-trifluorobut-3-en-2-one with hydrazines, hydroxylamine hydrochloride and acetylguanidine. (author)

  14. Substitution rates in the X- and Y-linked genes of the plants, Silene latifolia and S. dioica.

    Science.gov (United States)

    Filatov, Dmitry A; Charlesworth, Deborah

    2002-06-01

    Theory predicts that selection should be less effective in the nonrecombining genes of Y-chromosomes, relative to the situation for genes on the other chromosomes, and this should lead to the accumulation of deleterious nonsynonymous substitutions. In addition, synonymous substitution rates may differ between X- and Y-linked genes because of the male-driven evolution effect and also because of actual differences in per-replication mutation rates between the sex chromosomes. Here, we report the first study of synonymous and nonsynonymous substitution rates on plant sex chromosomes. We sequenced two pairs of sex-linked genes, SlX1-SlY1 and SlX4-SlY4, from dioecious Silene latifolia and S. dioica, and their non-sex-linked homologues from nondioecious S. vulgaris and Lychnis flos-jovis, respectively. The rate of nonsynonymous substitutions in the SlY4 gene is significantly higher than that in the SlX4 gene. Silent substitution rates are also significantly higher in both Y-linked genes, compared with their X-linked homologues. The higher nonsynonymous substitution rate in the SlY4 gene is therefore likely to be caused by a mutation rate difference between the sex chromosomes. The difference in silent substitution rates between the SlX4 and SlY4 genes is too great to be explained solely by a higher per-generation mutation rate in males than females. It is thus probably caused by a difference in per-replication mutation rates between the sex chromosomes. This suggests that the local mutation rate can change in a relatively short evolutionary time.

  15. 77 FR 5781 - Record of Decision for the Air Space Training Initiative Shaw Air Force Base, South Carolina...

    Science.gov (United States)

    2012-02-06

    ... DEPARTMENT OF DEFENSE Department of the Air Force Record of Decision for the Air Space Training Initiative Shaw Air Force Base, South Carolina Final Environmental Impact Statement ACTION: Notice of... signed the ROD for the Airspace Training Initiative Shaw Air Force Base, South Carolina Final...

  16. Robert R. Shaw, MD: thoracic surgical hero, Afghanistan medical pioneer, champion for the patient, never a surgical society president.

    Science.gov (United States)

    Urschel, Harold C; Urschel, Betsey Bradley

    2012-06-01

    Dr Robert R. Shaw arrived in Dallas to practice Thoracic Surgery in 1937, as John Alexander's 7th Thoracic Surgical Resident from Michigan University Medical Center. Dr Shaw's modus operandi was, "You can accomplish almost anything, if you don't care who gets the credit." He was a remarkable individual who cared the most about the patient and very little about getting credit for himself. From 1937 to 1970, Dr Shaw established one of the largest lung cancer surgical centers in the world in Dallas, Texas. It was larger than M.D. Anderson and Memorial Sloan-Kettering Hospitals put together regarding the surgical treatment of lung cancer patients. To accomplish this, he had the help of Dr Donald L. Paulson, who trained at the Mayo Clinic and served as Chief of Thoracic Surgery at Brook Army Hospital during the Second World War. Following the War, because of his love for Texas, he ended up as a partner of Dr Shaw in Dallas. Together, they pursued the development of this very large surgical lung cancer center. Dr Shaw and his wife Ruth went to Afghanistan with Medico multiple times to teach men modern cardiac and thoracic surgery. They also served as consultants on Medico's Ship of Hope in Africa. Dr Shaw initiated multiple new operations including: 1) resection of Pancoast's cancer of the lung after preoperative irradiation; 2) upper lobe of the lung bronchoplasty, reattaching (and saving) the lower lobe to prevent the "disabling" pneumonectomy; and 3) resections of pulmonary mucoid impaction of the lung in asthmatics. Because of his humility and giving "the credit to others," Dr Shaw was never President of a major medical or surgical association. Copyright © 2012 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  17. Thermal stability of 4-substituted benzenediazonium tetrafluoroborates

    International Nuclear Information System (INIS)

    Bruner, V.Ya.

    1990-01-01

    Heating of tetraborates of 4-methyl-, 4-phenyl- and 4-dimethylaminobenzenediazonium at 95, 120 and 148 deg, correspondingly, causes their autocatalytic destruction, two moles of gas (nitrogen, boron fluoride) being liberated. The thermal stability of 4-substituted benzenediazonium tetrafluoroborates increases with the increase of the electron-donor activity of the substituent at benzene ring

  18. Life support and euthanasia, a perspective on Shaw's new perspective.

    Science.gov (United States)

    Busch, Jacob; Rodogno, Raffaele

    2011-02-01

    It has recently been suggested by Shaw (2007) that the distinction between voluntary active euthanasia, such as giving a patient a lethal overdose with the intention of ending that patient's life, and voluntary passive euthanasia, such as removing a patient from a ventilator, is much less obvious than is commonly acknowledged in the literature. This is argued by suggesting a new perspective that more accurately reflects the moral features of end-of-life situations. The argument is simply that if we consider the body of a mentally competent patient who wants to die, a kind of 'unwarranted' life support, then the distinction collapses. We argue that all Shaw has provided is a perspective that makes the conclusion that there is little distinction between voluntary active euthanasia and voluntary passive euthanasia only seemingly more palatable. In doing so he has yet to convince us that this perspective is superior to other perspectives and thus more accurately reflects the moral features of the situations pertaining to this issue.

  19. Scaling crossover in thin-film drag dynamics of fluid drops in the Hele-Shaw cell

    Science.gov (United States)

    Okumura, Ko; Yahashi, Misato; Kimoto, Natsuki

    2016-11-01

    We study both experimentally and theoretically the descending motion due to gravity of a fluid drop surrounded by another immiscible fluid in a confined space between two parallel plates, i.e., in the Hele-Shaw cell. As a result, we show a new scaling regime of a nonlinear drag friction in viscous liquid that replaces the well-known Stokes' drag friction through a clear collapse of experimental data thanks to the scaling law. In the novel regime, the dissipation in the liquid thin film formed between the drop and cell walls governs the dynamics. The crossover of this scaling regime to another scaling regime in which the dissipation inside the droplet is dominant is clearly demonstrated and a phase diagram separating these scaling regimes is presented. To be published as, Y. Yahashi, N. Kimoto and K. Okumura, Scaling crossover in thin-film drag dynamics of fluid drops in the Hele-Shaw cell, Sci. Rep.(CC BY 4.0). This research was partly supported by ImPACT Program of Council for Science, Technology and Innovation (Cabinet Office, Government of Japan).

  20. On a Hele-Shaw flow with a time-dependent gap in the presence of surface tension

    International Nuclear Information System (INIS)

    Savina, T V; Nepomnyashchy, A A

    2015-01-01

    The introduction of surface tension into a Hele-Shaw problem makes it more realistic from the physical viewpoint, but more difficult from the mathematical viewpoint. In this paper we discuss a Hele-Shaw flow with a time-dependent gap taking into account the surface tension of the free boundary. We use the Schwarz function method to find asymptotic solutions for the interior problem in the case when the initial shape of the droplet is a weakly distorted circle. (paper)

  1. Determining the number of fingers in the lifting Hele-Shaw problem

    Science.gov (United States)

    Miranda, Jose; Dias, Eduardo

    2013-11-01

    The lifting Hele-Shaw cell flow is a variation of the celebrated radial viscous fingering problem for which the upper cell plate is lifted uniformly at a specified rate. This procedure causes the formation of intricate interfacial patterns. Most theoretical studies determine the total number of emerging fingers by maximizing the linear growth rate, but this generates discrepancies between theory and experiments. In this work, we tackle the number of fingers selection problem in the lifting Hele-Shaw cell by employing the recently proposed maximum-amplitude criterion. Our linear stability analysis accounts for the action of capillary, viscous normal stresses, and wetting effects, as well as the cell confinement. The comparison of our results with very precise laboratory measurements for the total number of fingers shows a significantly improved agreement between theoretical predictions and experimental data. We thank CNPq (Brazilian Sponsor) for financial support.

  2. Effects of disorder on the intrinsically hole-doped iron-based superconductor KC a2F e4A s4F2 by cobalt substitution

    Science.gov (United States)

    Ishida, Junichi; Iimura, Soshi; Hosono, Hideo

    2017-11-01

    In this paper, the effects of cobalt substitution on the transport and electronic properties of the recently discovered iron-based superconductor KC a2F e4A s4F2 , with Tc=33 K , are reported. This material is an unusual superconductor showing intrinsic hole conduction (0.25 holes /F e2 + ). Upon doping of Co, the Tc of KC a2(Fe1-xC ox) 4A s4F2 gradually decreased, and bulk superconductivity disappeared when x ≥0.25 . Conversion of the primary carrier from p type to n type upon Co-doping was clearly confirmed by Hall measurements, and our results are consistent with the change in the calculated Fermi surface. Nevertheless, neither spin density wave (SDW) nor an orthorhombic phase, which are commonly observed for nondoped iron-based superconductors, was observed in the nondoped or electron-doped samples. The electron count in the 3 d orbitals and structural parameters were compared with those of other iron-based superconductors to show that the physical properties can be primarily ascribed to the effects of disorder.

  3. George Bernard Shaw's "Androcles and the Lion": A Postmodernist Study

    Science.gov (United States)

    Hooti, Noorbakhsh; Jeihouni, Mojtaba

    2012-01-01

    This study makes an attempt to analyze the manifold aspects of Shaw's "Androcles and the Lion" on a postmodernist standpoint, meanwhile, demonstrates the dominion of modernism, which is portrayed through the vehicle of comedy with a bitter ironic language through the play. Regardless of the historical period in which the play occurs, the…

  4. Hele-Shaw beach creation by breaking waves: a mathematics-inspired experiment

    NARCIS (Netherlands)

    Thornton, Anthony Richard; van der Horn, Avraham/Bram; van der Horn, Avraham J.; Gagarina, Elena; Zweers, Wout; van der Meer, Roger M.; Bokhove, Onno

    2014-01-01

    Fundamentals of nonlinear wave-particle interactions are studied experimentally in a Hele-Shaw configuration with wave breaking and a dynamic bed. To design this configuration, we determine, mathematically, the gap width which allows inertial flows to survive the viscous damping due to the side

  5. The esophagus anatomic-histology of bull frog ("Rana catesbeiana" Shaw, 1802 Anatomo-histologia do esôfago da rã touro ("Rana catesbeiana" Shaw, 1802

    Directory of Open Access Journals (Sweden)

    Carlos Eduardo Lino Pinto

    2008-04-01

    Full Text Available Aiming to describe the esophage functional morpho – histology of bull frog (Rana catebeiana Shaw, 1802, twenty bull frog, mean body weight of 85.00 ± 2.03 g, were used. The esophageal mucosa architecture is defined by thick longitudinal folds, showing an esophageal ciliated pseudostratified epithelium with mucous cells and pluricellular glands; the esophageal muscular coat is composed by inner circular muscular lamina, and by outer longitudinal muscular lamina.Com o objetivo de descrever a anatomo histologia funcional do esôfago da rã touro (Rana catesbeiana Shaw, 1802, foram utilizados 20 (vinte exemplares de rã touro com peso médio de 85,00 ± 2,03 g. Verificou-se que a arquitetura da mucosa esofágica é definida por pregas espessas e longitudinais, com epitélio esofágico do tipo pseudo estratificado ciliado com células mucosas e glândulas pluricelulares; a túnica muscular esofágica é constituida pela túnica muscular circular, mais interna, e pela túnica muscular longitudinal, mais externa.

  6. Self-Expression or Teacher Influence: The Shaw System of Finger-Painting.

    Science.gov (United States)

    Stankiewicz, Mary Ann

    1984-01-01

    Finger painting is often regarded as the epitome of free expression for children. However, a careful review of the history of Ruth Shaw's finger-painting system reveals that it was dominated by specific techniques and stylistic conventions taught without a critical understanding of art history or appreciation. (IS)

  7. Factor substitution and rebound effect in China’s food industry

    International Nuclear Information System (INIS)

    Lin, Boqiang; Xie, Xuan

    2015-01-01

    Highlights: • The basic information of China’s food industry is introduced in detail. • Inter-factor substitution relationship in China’s food industry is analyzed. • Direct rebound effect in the industry is measured. • Several relevant policy suggestions about energy conservation are provided. - Abstract: Energy efficiency improvement can reduce the energy consumption of an industry, and thus promote energy conservation. However, the reduction of effective energy prices caused by energy efficiency improvement will lower energy costs for enterprises, making them substitute energy for other input factors. Therefore, energy conservation brought about by efficiency improvement will be partly offset. This offset is called the energy rebound effect of an industry. This paper estimates the system of cost share equations in China’s food industry, analyzes the substitution relationship between each input factor, and calculates the direct rebound effect. The results show that: there exist substitution relationships between energy and other input factors, among which the substitution elasticity between energy and labor is the biggest, and the substitution of energy for capital dominates that of capital for energy. The direct rebound effect is approximately 34.39%, which means that about 34.39% of energy conservation caused by energy efficiency enhancement in the industry has been offset by the rebound effect. The paper proposes some policy suggestions on energy conservation according to the results of substitution relationship among input factors and the rebound effect of the industry. The policy suggestions include reducing the capital and labor costs of the food industry by decreasing financing costs of small businesses, optimizing personnel management, and rationalizing the energy pricing mechanism to form a reasonable energy price.

  8. In silico binding affinity studies of N-9 substituted 6-(4-(4-propoxyphenylpiperazin-1-yl-9H-purine derivatives-Target for P70-S6K1 & PI3K-δ kinases

    Directory of Open Access Journals (Sweden)

    Manjunath G. Sunagar

    2018-03-01

    Full Text Available P70-S6K1 & PI3K-δ kinases are identified to be involved in many physiological processes associated with cancer, therefore many of the inhibitors being designed to target these kinases are in clinical trials. In the current study we have exploited the N-9 substituted 6-(4-(4-propoxyphenyl piperazin-1-yl-9H-purine derivatives for their inhibitory properties with the above kinases. We have used an in silico docking study with seventeen purine derivatives for their binding affinity calculations. The binding affinities of these small molecules with P70-S6K1 & PI3K-δ were performed using AutoDock Vina. Among all the compounds, PP16 showed highest binding affinity of −14.7 kcal/mol with P70-S6K1 kinase & −17.2 kcal/mol with PI3K-δ kinases as compared to the molecules under clinical trials (PF-4708671 & IC-87114. Docking studies revealed that N-9 coumarine substituted purine derivative could be one of the potential ligands for the inhibition of P70-S6K1 & PI3K-δ kinases. Hence, this compound can be further investigated by in vitro and in vivo experiments for further validation.

  9. EPR-study of reversible oxygenation process of coordination compounds of cobalt(II) with S-substituted N1,N4-di(salicylidene)-isothiosemicarbazides

    International Nuclear Information System (INIS)

    Gerbeleu, N.V.; Revenko, M.D.; Rusu, V.G.; Shames, A.T.

    1987-01-01

    The reaction between molecular oxygen and coordination compounds of cobalt(II) with S-substituted N 1 ,N 4 -di(salicylidene)isothiosemicarbazides in dimethyl sulfoxide solution was studied by the EPR method. It was found that paramagnetic monomeric adducts and diamagnetic μ-peroxo-dimers are formed. The spin-Hamiltonian parameters of the EPR spectra of the initial cobalt complexes, as well as of the paramagnetic adducts were determined. The nature of the Co-O 2 bond is discussed

  10. Computer simulation of viscous fingering in a lifting Hele-Shaw cell

    Indian Academy of Sciences (India)

    We simulate viscous fingering generated by separating two plates with a constant force, in a lifting Hele-Shaw cell. Variation in the patterns for different fluid viscosity and lifting force is studied. Viscous fingering is strongly affected by anisotropy. We report a computer simulation study of fingering patterns, where circular or ...

  11. Synthesis and Antimicrobial Activity of Some Novel Substituted Piperazinyl-quinazolin-3(4H-ones

    Directory of Open Access Journals (Sweden)

    N. M. Raghavendra

    2008-01-01

    Full Text Available Several substituted-quinazolin-3(4H-ones were synthesized by condensation of 2-chloro-N-(4-oxo-substituted-quinazolin-3(4H-yl-acetamides with various substituted piperazines through single step reaction. Elemental analysis, IR, 1HNMR and mass spectral data confirmed the structure of the newly synthesized compounds. Synthesized quinazolin-4-one derivatives were investigated for their antibacterial and antifungal activities.

  12. Fluoride substitution in LiBH4; destabilization and decomposition

    DEFF Research Database (Denmark)

    Richter, Bo; Ravnsbaek, Dorthe B.; Sharma, Manish

    2017-01-01

    Fluoride substitution in LiBH4 is studied by investigation of LiBH4-LiBF4 mixtures (9:1 and 3:1). Decomposition was followed by in situ synchrotron radiation X-ray diffraction (in situ SR-PXD), thermogravimetric analysis and differential scanning calorimetry with gas analysis (TGA/DSC-MS) and in ......Fluoride substitution in LiBH4 is studied by investigation of LiBH4-LiBF4 mixtures (9:1 and 3:1). Decomposition was followed by in situ synchrotron radiation X-ray diffraction (in situ SR-PXD), thermogravimetric analysis and differential scanning calorimetry with gas analysis (TGA...

  13. Trypanocidal 1,3-arylene diketone bis(guanylhydrazone)s. Structure-activity relationships among substituted and heterocyclic analogues.

    Science.gov (United States)

    Ulrich, P; Cerami, A

    1984-01-01

    Based on the antitrypanosomal activity of 1,3-diacetylbenzene bis(guanylhydrazone) (4) and 2,6-diacetylpyridine bis(guanylhydrazone) (17), a number of substituted and heterocyclic 1,3-arylene diketone bis(guanylhydrazone)s were prepared and tested against Trypanosoma brucei infections in mice. A wide range of ED50 values was observed among 5-substituted derivatives of 4. The 5-amino analogue 5 and 5-acetamido analogue 6 were about twice as active as 4. 1,3,5-Triacetylbenzene tris(guanylhydrazone) (12) was about 9 times as active as 4 and was approximately one-half as active as the currently used trypanocide diminazene aceturate in this test system. Other 5-derivatives had activity equivalent to or less than that of the parent compound 4. Three new heterocyclic analogues were all less active than 2,6-diacetylpyridine derivative 17 and benzene derivative 4. Ring substitution ortho to the guanylhydrazone side chains was invariably detrimental to activity. Side-chain homologues 1,3-dipentanoylbenzene bis(guanylhydrazone) and 1,3-diacetylbenzene bis(2-imidazolin-2-ylhydrazone) were essentially inactive.

  14. Dihydroxylation of 4-substituted 1,2-dioxines

    DEFF Research Database (Denmark)

    Robinson, Tony V; Pedersen, Daniel Sejer; Taylor, Dennis K

    2009-01-01

    The synthesis of 2-C-branched erythritol derivatives, including the plant sugar (+/-)-2-C-methylerythritol 2, was achieved through a dihydroxylation/reduction sequence on a series of 4-substituted 1,2-dioxines 3. The asymmetric dihydroxylation of 1,2-dioxines was examined, providing access...... to optically enriched dihydroxy 1,2-dioxanes 4. The synthesized 1,2-dioxanes were converted to other erythro sugar analogues and tetrahydrofurans through controlled cleavage of the endoperoxide linkage....

  15. Sloshing in a Hele-Shaw cell: experiments and theory

    OpenAIRE

    Viola , Francesco; Gallaire , Francois; Dollet , Benjamin

    2017-01-01

    International audience; The response of the free liquid surface in a Hele-Shaw cell subjected to a horizontal oscillation is investigated. We study the low-oscillation-amplitude regime and we show, by varying the fluid viscosity, ν, and the forcing frequency, ω, that the ratio between the Stokes viscous length, 2ν/ω, and the cell thickness greatly affects the amplitude and phase lag of the gravity waves. In particular, the sloshing system undergoes an under-damped/overdamped transition for su...

  16. 1,3- and 1,4-Substituted tetrazolium salts

    International Nuclear Information System (INIS)

    Voitekhovich, Sergei V; Gaponik, Pavel N; Ivashkevich, Oleg A

    2002-01-01

    The published data on the synthesis, physicochemical properties, structures and reactions of 1,3-(1,3,5)- and 1,4-(1,4,5)-substituted tetrazolium salts are systematised and generalised. Their applications as starting compounds in the preparative chemistry of heterocyclic derivatives and some other branches of science and technology are reviewed. The bibliography includes 122 references.

  17. Enhancement of Electrochemical Performance of LiMn2O4 Spinel Cathode Material by Synergetic Substitution with Ni and S

    Directory of Open Access Journals (Sweden)

    Monika Bakierska

    2016-05-01

    Full Text Available Nickel and sulfur doped lithium manganese spinels with a nominal composition of LiMn2−xNixO4–ySy (0.1 ≤ x ≤ 0.5 and y = 0.01 were synthesized by a xerogel-type sol-gel method followed by subsequent calcinations at 300 and 650 °C in air. The samples were investigated in terms of physicochemical properties using X-ray powder diffraction (XRD, transmission electron microscopy (EDS-TEM, N2 adsorption-desorption measurements (N2-BET, differential scanning calorimetry (DSC, and electrical conductivity studies (EC. Electrochemical characteristics of Li/Li+/LiMn2−xNixO4–ySy cells were examined by galvanostatic charge/discharge tests (CELL TEST, electrochemical impedance spectroscopy (EIS, and cyclic voltammetry (CV. The XRD showed that for samples calcined at 650 °C containing 0.1 and 0.2 mole of Ni single phase materials of Fd-3m group symmetry and nanoparticles size of around 50 nm were obtained. The energy dispersive X-ray spectroscopy (EDS mapping confirmed homogenous distribution of nickel and sulfur in the obtained spinel materials. Moreover, it was revealed that the adverse phase transition at around room temperature typical for the stoichiometric spinel was successfully suppressed by Ni and S substitution. Electrochemical results indicated that slight substitution of nickel (x = 0.1 and sulfur (y = 0.01 in the LiMn2O4 enhances the electrochemical performance along with the rate capability and capacity retention.

  18. Faraday waves in a Hele-Shaw cell

    Science.gov (United States)

    Li, Jing; Li, Xiaochen; Chen, Kaijie; Xie, Bin; Liao, Shijun

    2018-04-01

    We investigate Faraday waves in a Hele-Shaw cell via experimental, numerical, and theoretical studies. Inspired by the Kelvin-Helmholtz-Darcy theory, we develop the gap-averaged Navier-Stokes equations and end up with the stable standing waves with half frequency of the external forced vibration. To overcome the dependency of a numerical model on the experimental parameter of wave length, we take two-phase flow into consideration and a novel dispersion relation is derived. The numerical results compare well with our experimental data, which effectively validates our proposed mathematical model. Therefore, this model can produce robust solutions of Faraday wave patterns and resolve related physical phenomena, which demonstrates the practical importance of the present study.

  19. Computational Chemistry of Modified [MFe3S4] and [M2Fe2S4] Clusters: Assessment of Trends in Electronic Structure and Properties

    DEFF Research Database (Denmark)

    Kepp, Kasper Planeta; Ooi, Bee Lean; Christensen, Hans Erik Mølager

    2008-01-01

    The aim of this work is to understand the molecular evolution of iron−sulfur clusters in terms of electronic structure and function. Metal-substituted models of biological [Fe4S4] clusters in oxidation states [MxFe4−xS4]3+/2+/1+ have been studied by density functional theory (M = Cr, Mn, Fe, Co, ...

  20. Present developmental conditions of petroleum substituting energies in the U.S.A; Sekiyu daitai energy no kaihatsu no genjo (Beikoku)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    The present developmental conditions of petroleum substituting energies in the U.S.A. were surveyed. The budget related to energy saving and petroleum substituting energies in the U.S.A. is on the increase. DOE`s expenditure on petroleum substituting energies increased from $6.8 billion in 1993 to $8.1 billion in 1995 (from 29.6% to 34.6% of DOE`s expenditure), showing the positive approach to development of petroleum substituting energies. Approaches to environmental protection are also in promotion such as positive use of electrical vehicles by U.S. government and emission regulation of specific pollutants by EPA. The state of California withdrew the regulation which prescribes that 2% of passenger cars sold in the state should be zero emission vehicles after 1998, because development of the battery with both sufficient mileage and output is impossible by 1998 in the present stage. The prospect of practical use of new batteries such as lithium battery is still far from certain for some years. Development of petroleum substituting energies in the U.S.A. is still insufficient. 17 refs., 1 fig., 4 tabs.

  1. Gas driven displacement in a Hele-Shaw cell with chemical reaction

    Science.gov (United States)

    White, Andrew; Ward, Thomas

    2011-11-01

    Injecting a less viscous fluid into a more viscous fluid produces instabilities in the form of fingering which grow radially from the less viscous injection point (Saffman & Taylor, Proc. R. Soc. Lon. A, 1958). For two non-reacting fluids in a radial Hele-Shaw cell the ability of the gas phase to penetrate the liquid phase is largely dependent on the gap height, liquid viscosity and gas pressure. In contrast combining two reactive fluids such as aqueous calcium hydroxide and carbon dioxide, which form a precipitate, presents a more complex but technically relevant system. As the two species react calcium carbonate precipitates and increases the aqueous phase visocosity. This change in viscosity may have a significant impact on how the gas phase penetrates the liquid phase. Experimental are performed in a radial Hele-Shaw cell with gap heights O(10-100) microns by loading a single drop of aqueous calcium hydroxide and injecting carbon dioxide into the drop. The calcium hydroxide concentration, carbon dioxide pressure and gap height are varied and images of the gas penetration are analyzed to determine residual film thickness and bursting times.

  2. Synthesis, characterization of N-, S-, O-substituted naphtho- and ...

    Indian Academy of Sciences (India)

    obtained on a Thermo Finnigan LCQ Advantage MAX. LC/MS/MS spectrometer .... organic layer was washed with water (4 × 30 mL), and dried with Na2SO4. ..... mono(thio)-substituted compounds containing chlorine atom derivatives were.

  3. Quantitation of base substitutions in eukaryotic 5S rRNA: selection for the maintenance of RNA secondary structure.

    Science.gov (United States)

    Curtiss, W C; Vournakis, J N

    1984-01-01

    Eukaryotic 5S rRNA sequences from 34 diverse species were compared by the following method: (1) The sequences were aligned; (2) the positions of substitutions were located by comparison of all possible pairs of sequences; (3) the substitution sites were mapped to an assumed general base pairing model; and (4) the R-Y model of base stacking was used to study stacking pattern relationships in the structure. An analysis of the sequence and structure variability in each region of the molecule is presented. It was found that the degree of base substitution varies over a wide range, from absolute conservation to occurrence of over 90% of the possible observable substitutions. The substitutions are located primarily in stem regions of the 5S rRNA secondary structure. More than 88% of the substitutions in helical regions maintain base pairing. The disruptive substitutions are primarily located at the edges of helical regions, resulting in shortening of the helical regions and lengthening of the adjacent nonpaired regions. Base stacking patterns determined by the R-Y model are mapped onto the general secondary structure. Intrastrand and interstrand stacking could stabilize alternative coaxial structures and limit the conformational flexibility of nonpaired regions. Two short contiguous regions are 100% conserved in all species. This may reflect evolutionary constraints imposed at the DNA level by the requirement for binding of a 5S gene transcription initiation factor during gene expression.

  4. Enhanced electrochemical performance of Ti substituted P2-Na2/3Ni1/4Mn3/4O2 cathode material for sodium ion batteries

    International Nuclear Information System (INIS)

    Zhao, Wenwen; Tanaka, Akinobu; Momosaki, Kyoko; Yamamoto, Shinji; Zhang, Fabi; Guo, Qixin; Noguchi, Hideyuki

    2015-01-01

    Highlights: • Ti substituted P2-Na 2/3 Ni 1/4 Mn 3/4 O 2 cathode was synthesized. • Structural and electrochemical properties of Na 2/3 Ni 1/4 Ti x Mn 3/4-x O 2 were studied. • Ti substituted cathodes exhibit enhanced cycleability and rate performance. • Ti substitution has impact on stabilizing the P2 structure during cycling. -- Abstract: Ti substituted P2-Na 2/3 Ni 1/4 Mn 3/4 O 2 cathode material with the composition of Na 2/3 Ni 1/4 Ti x Mn 3/4-x O 2 has been synthesized by solid state method. The influence of Ti substitution for Mn on the structure, morphology and electrochemical performances of P2-Na 2/3 Ni 1/4 Mn 3/4 O 2 has been investigated. X-ray diffraction (XRD) results of Ti substituted sample show that they exhibit same diffraction patterns as those of pristine P2-Na 2/3 Ni 1/4 Mn 3/4 O 2 . Progressive change in the lattice parameters of Ti substituted samples suggests that Mn was successfully substituted by Ti. In contrast to P2-Na 2/3 Ni 1/4 Mn 3/4 O 2 which shows step-type voltage profiles, Ti substituted samples show sloping voltage profiles. Drastic capacity fade occurred for P2-Na 2/3 Ni 1/4 Mn 3/4 O 2 cathode, while Ti substituted cathodes still show high capacity retention over 92% after 25 cycles at the voltage range of 2.0-4.3 V. Even cycled at high upper cut-off voltage of 4.5 V, Ti=0.20 sample can deliver a reversible capacity of 140 mAhg −1 with the capacity retention over 92% after 25 cycles. Furthermore, Ti substituted cathodes exhibit enhanced rate capability over pristine P2-Na 2/3 Ni 1/4 Mn 3/4 O 2 cathode. Comparison of the Ex-situ XRD results of the cycled P2-Na 2/3 Ni 1/4 Mn 3/4 O 2 and its substituted samples provides evidence that the improved electrochemical performance of Ti substituted cathodes would be attributed to the stabilization of the structure with Ti substitution

  5. Mixing foams and grains in Hele-Shaw cells

    Energy Technology Data Exchange (ETDEWEB)

    Tufaile, A P B; Tufaile, A; Haddad, T A S, E-mail: tufaile@usp.b [Escola de Artes, Ciencias e Humanidades da Universidade de Sao Paulo, R. Arlindo Bettio, 1000, 03828-000, Sao Paulo (Brazil)

    2010-09-01

    We have observed some features of the coexistence of foams and granular materials in Hele-Shaw cells. The most part of the liquid and granular material stays at the bottom of the cell, with only a small quantity of the mixture resting on the froth. The fractal dimensions of the final states of the foams are close to the values obtained from the Random Apollonian Packing model. The disperse structure of the granular material affects the probability distribution of number of sides of the foam bubbles. The nearest neighbor distances between the peaks of the sand piles at the bottom of the cell are close to a lognormal distribution.

  6. Synthesis and Antimicrobial Activity of Novel Substituted Ethyl 2-(Quinolin-4-yl-propanoates

    Directory of Open Access Journals (Sweden)

    Yong Zhou

    2013-03-01

    Full Text Available Substituted 4-hydroxyquinolines were synthesized from anilines and diethyl 2-(ethoxymethylenemalonate by the Gould-Jacobs reaction via cyclization of the intermediate anilinomethylenemalonate followed by hydrolysis and decarboxylation. The 4-hydroxyquinolines reacted with phosphorous oxychloride to form 4-chloroquinolines, which reacted on heating with diethyl sodiomethylmalonate in DMF to yield moderate yields of substituted ethyl 2-(quinolin-4-ylpropanoates, many of which showed potent antimicrobial activity against Helicobacter pylori.

  7. 8 CFR 1246.4 - Immigration judge's authority; withdrawal and substitution.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Immigration judge's authority; withdrawal and substitution. 1246.4 Section 1246.4 Aliens and Nationality EXECUTIVE OFFICE FOR IMMIGRATION REVIEW, DEPARTMENT OF JUSTICE IMMIGRATION REGULATIONS RESCISSION OF ADJUSTMENT OF STATUS § 1246.4 Immigration judge's...

  8. EPR-study of reversible oxygenation process of coordination compounds of cobalt(II) with S-substituted N/sup 1/,N/sup 4/-di(salicylidene)-isothiosemicarbazides

    Energy Technology Data Exchange (ETDEWEB)

    Gerbeleu, N.V.; Revenko, M.D.; Rusu, V.G.; Shames, A.T.

    1987-09-01

    The reaction between molecular oxygen and coordination compounds of cobalt(II) with S-substituted N/sup 1/,N/sup 4/-di(salicylidene)isothiosemicarbazides in dimethyl sulfoxide solution was studied by the EPR method. It was found that paramagnetic monomeric adducts and diamagnetic ..mu..-peroxo-dimers are formed. The spin-Hamiltonian parameters of the EPR spectra of the initial cobalt complexes, as well as of the paramagnetic adducts were determined. The nature of the Co-O/sub 2/ bond is discussed.

  9. Synthesis and solid-state characterisation of 4-substituted methylidene oxindoles

    Science.gov (United States)

    2013-01-01

    Background 4-substituted methylidene oxindoles are pharmacologically important. Detailed analysis and comparison of all the interactions present in crystal structures is necessary to understand how these structures arise. The XPac procedure allows comparison of complete crystal structures of related families of compounds to identify assemblies that are mainly the result of close-packing as well as networks of directed interactions. Results Five 4-substituted methylidene oxindoles have been synthesized by the Knoevenagel condensation of oxindole with para-substituted aromatic aldehydes and were characterized in the solid state by x-ray crystallography. Hence, the structures of (3E)-3-(4-Bromobenzylidene)-1,3-dihydro-2H-indol-2-one, 3a, (3E)-3-(4-Chlorobenzylidene)-1,3-dihydro-2H-indol-2-one, 3b, (3E)-3-(4-Methoxybenzylidene)-1,3-dihydro-2H-indol-2-one, 3c, (3E)-3-(4-Methylbenzylidene)-1,3-dihydro-2H-indol-2-one, 3d and (3E)-3-(4-Nitrobenzylidene)-1,3-dihydro-2H-indol-2-one, 3e, were elucidated using single crystal X-ray crystallography. Conclusions A hydrogen bonded dimer molecular assembly or supramolecular construct was identified in all the crystal structures examined along with a further four 1D supramolecular constructs which were common to at least two of the family of structures studied. The 1D supramolecular constructs indicate that once the obvious strong interaction is satisfied to form hydrogen bonded dimer it is the conventionally weaker interactions, such as steric bulk and edge-to-face interactions which compete to influence the final structure formation. PMID:24517531

  10. Tuning ZrFe{sub 4}Si{sub 2} by Ge and Y substitution

    Energy Technology Data Exchange (ETDEWEB)

    Weber, Katharina [Max Planck Institute for Chemical Physics of Solids, Dresden (Germany); Institute of Solid State Physics, TU Dresden (Germany); Mufti, Nandang; Bergmann, Christoph; Rosner, Helge; Geibel, Christoph [Max Planck Institute for Chemical Physics of Solids, Dresden (Germany); Goltz, Til; Klauss, Hans-Henning [Institute of Solid State Physics, TU Dresden (Germany); Woike, Theo [Institute for Structural Physics, TU Dresden (Germany)

    2016-07-01

    The intermetallic compound series AFe{sub 4}X{sub 2} (A = Y, Lu, Zr; X = Si, Ge) presents a rare case of magnetic frustrated metallic systems. In particular ZrFe{sub 4}Si{sub 2} is of strong interest because our results indicate this system to be very close to a quantum critical point (QCP) where Fe magnetic order disappears. To get a deeper insight into its ground state, we performed a detailed study of Ge and Y substituted ZrFe{sub 4}Si{sub 2}. The isovalent substitution of Ge for Si induces a negative chemical pressure as Ge is larger than Si. As expected from this, the substitution results in the formation of a well-defined antiferromagnetic order with Neel temperatures increasing up to 25 K at 40 % Ge. This confirms ZrFe{sub 4}Si{sub 2} to be extremely close to the QCP, just on the magnetic side of it. With the second substitution series Y{sub x}Zr{sub 1-x}Fe{sub 4}Si{sub 2} we investigate the development from the highly reduced antiferromagnetic order in ZrFe{sub 4}Si{sub 2} towards the two magnetic transitions at 56 K and 76 K, which we see in YFe{sub 4}Si{sub 2}.

  11. Contracting bubbles in Hele-Shaw cells with a power-law fluid

    International Nuclear Information System (INIS)

    McCue, Scott W; King, John R

    2011-01-01

    The problem of bubble contraction in a Hele-Shaw cell is studied for the case in which the surrounding fluid is of power-law type. A small perturbation of the radially symmetric problem is first considered, focussing on the behaviour just before the bubble vanishes, it being found that for shear-thinning fluids the radially symmetric solution is stable, while for shear-thickening fluids the aspect ratio of the bubble boundary increases. The borderline (Newtonian) case considered previously is neutrally stable, the bubble boundary becoming elliptic in shape with the eccentricity of the ellipse depending on the initial data. Further light is shed on the bubble contraction problem by considering a long thin Hele-Shaw cell: for early times the leading-order behaviour is one-dimensional in this limit; however, as the bubble contracts its evolution is ultimately determined by the solution of a Wiener–Hopf problem, the transition between the long thin limit and the extinction limit in which the bubble vanishes being described by what is in effect a similarity solution of the second kind. This same solution describes the generic (slit-like) extinction behaviour for shear-thickening fluids, the interface profiles that generalize the ellipses that characterize the Newtonian case being constructed by the Wiener–Hopf calculation

  12. Cu-catalyzed aerobic oxidative cyclizations of 3-N-hydroxyamino-1,2-propadienes with alcohols, thiols, and amines to form α-O-, S-, and N-substituted 4-methylquinoline derivatives.

    Science.gov (United States)

    Sharma, Pankaj; Liu, Rai-Shung

    2015-03-16

    A one-pot, two-step synthesis of α-O-, S-, and N-substituted 4-methylquinoline derivatives through Cu-catalyzed aerobic oxidations of N-hydroxyaminoallenes with alcohols, thiols, and amines is described. This reaction sequence involves an initial oxidation of N-hydroxyaminoallenes with NuH (Nu = OH, OR, NHR, and SR) to form 3-substituted 2-en-1-ones, followed by Brønsted acid catalyzed intramolecular cyclizations of the resulting products. Our mechanistic analysis suggests that the reactions proceed through a radical-type mechanism rather than a typical nitrone-intermediate route. The utility of this new Cu-catalyzed reaction is shown by its applicability to the synthesis of several 2-amino-4-methylquinoline derivatives, which are known to be key precursors to several bioactive molecules. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Synthesis and antitumoral activity of novel 3-(2-substituted-1,3,4-oxadiazol-5-yl) and 3-(5-substituted-1,2,4-triazol-3-yl) beta-carboline derivatives.

    Science.gov (United States)

    Formagio, Anelise S Nazari; Tonin, Lilian T Düsman; Foglio, Mary Ann; Madjarof, Christiana; de Carvalho, João Ernesto; da Costa, Willian Ferreira; Cardoso, Flávia P; Sarragiotto, Maria Helena

    2008-11-15

    Several novel 1-substituted-phenyl beta-carbolines bearing the 2-substituted-1,3,4-oxadiazol-5-yl and 5-substituted-1,2,4-triazol-3-yl groups at C-3 were synthesized and evaluated for their in vitro anticancer activity. The assay results pointed thirteen compounds with growth inhibition effect (GI(50)<100 microM) for all eight different types of human cancer cell lines tested. The beta-carbolines 7a and 7h, bearing the 3-(2-metylthio-1,3,4-oxadiazol-5-yl) group, displayed high selectivity and potent anticancer activity against ovarian cell line with GI(50) values lying in the nanomolar concentration range (GI(50)=10 nM for both compounds). The 1-(N,N-dimethylaminophenyl)-3-(5-thioxo-1,2,4-triazol-3-yl) beta-carboline (8g) was the most active compound, showing particular effectiveness on lung (GI(50)=0.06 microM), ovarian and renal cell lines. The potent anticancer activity presented for synthesized compounds 7a, 7h, and 8g, together with their easiness of synthesis, makes these compounds promising anticancer agents.

  14. Researcher’s Perspective of Substitution Method on Text Steganography

    Science.gov (United States)

    Zamir Mansor, Fawwaz; Mustapha, Aida; Azah Samsudin, Noor

    2017-08-01

    The linguistic steganography studies are still in the stage of development and empowerment practices. This paper will present several text steganography on substitution methods based on the researcher’s perspective, all scholar paper will analyse and compared. The objective of this paper is to give basic information in the substitution method of text domain steganography that has been applied by previous researchers. The typical ways of this method also will be identified in this paper to reveal the most effective method in text domain steganography. Finally, the advantage of the characteristic and drawback on these techniques in generally also presented in this paper.

  15. Magnesium substitution in carbonated hydroxyapatite: Structural and microstructural characterization by Rietveld's refinement

    Energy Technology Data Exchange (ETDEWEB)

    Lala, S. [Materials Science Division, Department of Physics, The University of Burdwan, Golapbag, Burdwan 713104, West Bengal (India); Ghosh, M.; Das, P.K. [Department of Biological Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032 (India); Das, D. [UGC-DAE Consortium for Scientific Research, Kolkata 700098 (India); Kar, T. [Department of Materials Science, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032 (India); Pradhan, S.K., E-mail: skpradhan@phys.buruniv.ac.in [Materials Science Division, Department of Physics, The University of Burdwan, Golapbag, Burdwan 713104, West Bengal (India)

    2016-02-15

    Four stoichiometric compositions of nanocrystalline Mg doped carbonated hydroxyapatite (cHAp) powders are synthesized by mechanical alloying (ball milling) the powder mixtures of CaCO{sub 3}, CaHPO{sub 4}.2H{sub 2}O and MgO in open air at room temperature. FTIR analysis confirms the A-type carbonation in all milled HAp powder samples (A-cHAp). Microstructure characterization in terms of lattice imperfections and phase quantification of ball milled samples are made by analyzing XRD patterns employing Rietveld's structure refinement method. Transmission electron microscopy (TEM) study of 15 mol % Mg doped A-cHAp sample reveals microstructure similar to that obtained from XRD pattern analysis. Cumulative effect of Mg substitution and mechanical alloying results in amorphization of a major part of crystalline A-cHAp, analogous to native bone mineral. Rietveld analysis reveals that the Ca2 vacancy site is energetically more favorable for occupation of Mg substitution. MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay test reveals sufficiently high percentage cell viability confirming the cytocompatibility of the sample. - Graphical abstract: Mg substitution for Ca2 site. - Highlights: • Single phase Mg doped A-cHAp synthesized by mechanical alloying (MA). • FTIR analysis confirms A-type carbonation in HAp. • Amorphization of a part of crystalline A-cHAp due to MA and Mg insertion. • Mg{sup 2+} ions substitute the Ca2 vacancy site. • High cell viability under MTT assay.

  16. Contribution of S4 segments and S4-S5 linkers to the low-voltage activation properties of T-type CaV3.3 channels.

    Directory of Open Access Journals (Sweden)

    Ana Laura Sanchez-Sandoval

    Full Text Available Voltage-gated calcium channels contain four highly conserved transmembrane helices known as S4 segments that exhibit a positively charged residue every third position, and play the role of voltage sensing. Nonetheless, the activation range between high-voltage (HVA and low-voltage (LVA activated calcium channels is around 30-40 mV apart, despite the high level of amino acid similarity within their S4 segments. To investigate the contribution of S4 voltage sensors for the low-voltage activation characteristics of CaV3.3 channels we constructed chimeras by swapping S4 segments between this LVA channel and the HVA CaV1.2 channel. The substitution of S4 segment of Domain II in CaV3.3 by that of CaV1.2 (chimera IIS4C induced a ~35 mV shift in the voltage-dependence of activation towards positive potentials, showing an I-V curve that almost overlaps with that of CaV1.2 channel. This HVA behavior induced by IIS4C chimera was accompanied by a 2-fold decrease in the voltage-dependence of channel gating. The IVS4 segment had also a strong effect in the voltage sensing of activation, while substitution of segments IS4 and IIIS4 moved the activation curve of CaV3.3 to more negative potentials. Swapping of IIS4 voltage sensor influenced additional properties of this channel such as steady-state inactivation, current decay, and deactivation. Notably, Domain I voltage sensor played a major role in preventing CaV3.3 channels to inactivate from closed states at extreme hyperpolarized potentials. Finally, site-directed mutagenesis in the CaV3.3 channel revealed a partial contribution of the S4-S5 linker of Domain II to LVA behavior, with synergic effects observed in double and triple mutations. These findings indicate that IIS4 and, to a lesser degree IVS4, voltage sensors are crucial in determining the LVA properties of CaV3.3 channels, although the accomplishment of this function involves the participation of other structural elements like S4-S5 linkers.

  17. Contribution of S4 segments and S4-S5 linkers to the low-voltage activation properties of T-type CaV3.3 channels

    Science.gov (United States)

    Sanchez-Sandoval, Ana Laura; Herrera Carrillo, Zazil; Díaz Velásquez, Clara Estela; Delgadillo, Dulce María; Rivera, Heriberto Manuel

    2018-01-01

    Voltage-gated calcium channels contain four highly conserved transmembrane helices known as S4 segments that exhibit a positively charged residue every third position, and play the role of voltage sensing. Nonetheless, the activation range between high-voltage (HVA) and low-voltage (LVA) activated calcium channels is around 30–40 mV apart, despite the high level of amino acid similarity within their S4 segments. To investigate the contribution of S4 voltage sensors for the low-voltage activation characteristics of CaV3.3 channels we constructed chimeras by swapping S4 segments between this LVA channel and the HVA CaV1.2 channel. The substitution of S4 segment of Domain II in CaV3.3 by that of CaV1.2 (chimera IIS4C) induced a ~35 mV shift in the voltage-dependence of activation towards positive potentials, showing an I-V curve that almost overlaps with that of CaV1.2 channel. This HVA behavior induced by IIS4C chimera was accompanied by a 2-fold decrease in the voltage-dependence of channel gating. The IVS4 segment had also a strong effect in the voltage sensing of activation, while substitution of segments IS4 and IIIS4 moved the activation curve of CaV3.3 to more negative potentials. Swapping of IIS4 voltage sensor influenced additional properties of this channel such as steady-state inactivation, current decay, and deactivation. Notably, Domain I voltage sensor played a major role in preventing CaV3.3 channels to inactivate from closed states at extreme hyperpolarized potentials. Finally, site-directed mutagenesis in the CaV3.3 channel revealed a partial contribution of the S4-S5 linker of Domain II to LVA behavior, with synergic effects observed in double and triple mutations. These findings indicate that IIS4 and, to a lesser degree IVS4, voltage sensors are crucial in determining the LVA properties of CaV3.3 channels, although the accomplishment of this function involves the participation of other structural elements like S4-S5 linkers. PMID:29474447

  18. Contribution of S4 segments and S4-S5 linkers to the low-voltage activation properties of T-type CaV3.3 channels.

    Science.gov (United States)

    Sanchez-Sandoval, Ana Laura; Herrera Carrillo, Zazil; Díaz Velásquez, Clara Estela; Delgadillo, Dulce María; Rivera, Heriberto Manuel; Gomora, Juan Carlos

    2018-01-01

    Voltage-gated calcium channels contain four highly conserved transmembrane helices known as S4 segments that exhibit a positively charged residue every third position, and play the role of voltage sensing. Nonetheless, the activation range between high-voltage (HVA) and low-voltage (LVA) activated calcium channels is around 30-40 mV apart, despite the high level of amino acid similarity within their S4 segments. To investigate the contribution of S4 voltage sensors for the low-voltage activation characteristics of CaV3.3 channels we constructed chimeras by swapping S4 segments between this LVA channel and the HVA CaV1.2 channel. The substitution of S4 segment of Domain II in CaV3.3 by that of CaV1.2 (chimera IIS4C) induced a ~35 mV shift in the voltage-dependence of activation towards positive potentials, showing an I-V curve that almost overlaps with that of CaV1.2 channel. This HVA behavior induced by IIS4C chimera was accompanied by a 2-fold decrease in the voltage-dependence of channel gating. The IVS4 segment had also a strong effect in the voltage sensing of activation, while substitution of segments IS4 and IIIS4 moved the activation curve of CaV3.3 to more negative potentials. Swapping of IIS4 voltage sensor influenced additional properties of this channel such as steady-state inactivation, current decay, and deactivation. Notably, Domain I voltage sensor played a major role in preventing CaV3.3 channels to inactivate from closed states at extreme hyperpolarized potentials. Finally, site-directed mutagenesis in the CaV3.3 channel revealed a partial contribution of the S4-S5 linker of Domain II to LVA behavior, with synergic effects observed in double and triple mutations. These findings indicate that IIS4 and, to a lesser degree IVS4, voltage sensors are crucial in determining the LVA properties of CaV3.3 channels, although the accomplishment of this function involves the participation of other structural elements like S4-S5 linkers.

  19. A Special Class of Univalent Functions in Hele-Shaw Flow Problems

    Directory of Open Access Journals (Sweden)

    Paula Curt

    2011-01-01

    Full Text Available We study the time evolution of the free boundary of a viscous fluid for planar flows in Hele-Shaw cells under injection. Applying methods from the theory of univalent functions, we prove the invariance in time of Φ-likeness property (a geometric property which includes starlikeness and spiral-likeness for two basic cases: the inner problem and the outer problem. We study both zero and nonzero surface tension models. Certain particular cases are also presented.

  20. Investigation and visualization of liquid–liquid flow in a vertically mounted Hele-Shaw cell: flow regimes, velocity and shape of droplets

    International Nuclear Information System (INIS)

    Shad, S; Gates, I D; Maini, B B

    2009-01-01

    The motion and shape of a liquid drop flowing within a continuous, conveying liquid phase in a vertical Hele-Shaw cell were investigated experimentally. The continuous phase was more viscous and wetted the bounding walls of the Hele-Shaw cell. The gap between the Hele-Shaw plates was set equal to 0.0226 cm. Four different flow regimes were observed: (a) small-droplet flow, (b) elongated-droplet flow, (c) churn flow and (d) channel flow. At low capillary number, that is, when capillary forces are larger than viscous forces, the droplet shape was irregular and changed with time and distance, and it moved with lower velocity than that of the conveying phase. At higher capillary number, several different shapes of stabilized elongated and flattened drops were observed. In contrast to gas–liquid systems, the velocities of droplets are higher than that of conveying liquid. New correlations derived from dimensionless analysis and fitted to the experimental data were generated to predict the elongated-drop velocity and aspect ratio

  1. Investigation and visualization of liquid-liquid flow in a vertically mounted Hele-Shaw cell: flow regimes, velocity and shape of droplets

    Science.gov (United States)

    Shad, S.; Gates, I. D.; Maini, B. B.

    2009-11-01

    The motion and shape of a liquid drop flowing within a continuous, conveying liquid phase in a vertical Hele-Shaw cell were investigated experimentally. The continuous phase was more viscous and wetted the bounding walls of the Hele-Shaw cell. The gap between the Hele-Shaw plates was set equal to 0.0226 cm. Four different flow regimes were observed: (a) small-droplet flow, (b) elongated-droplet flow, (c) churn flow and (d) channel flow. At low capillary number, that is, when capillary forces are larger than viscous forces, the droplet shape was irregular and changed with time and distance, and it moved with lower velocity than that of the conveying phase. At higher capillary number, several different shapes of stabilized elongated and flattened drops were observed. In contrast to gas-liquid systems, the velocities of droplets are higher than that of conveying liquid. New correlations derived from dimensionless analysis and fitted to the experimental data were generated to predict the elongated-drop velocity and aspect ratio.

  2. Billy Shaw Dam and Reservoir : Environmental Assessment and Finding of No Significant Impacts.

    Energy Technology Data Exchange (ETDEWEB)

    United States. Bonneville Power Administration; Shoshone-Paiute Tribes of the Duck Valley Reservation, Nevada.

    1997-03-01

    This notice announces BPA`s decision to fund the construction, operation, and maintenance of the Billy Shaw Dam and Reservoir on the Duck Valley Reservation. This project is part of a continuing effort to address system-wide fish and wildlife losses caused by the development of the hydropower system in the Columbia River Basin. BPA has prepared an Environmental Assessment (EA) evaluating the potential environmental impacts of the proposed project. Based on the analysis in the EA, BPA has determined that the Proposed Action is not a major Federal action significantly affecting the quality of the human environment, within the meaning of the National Environmental Policy Act (NEPA) of 1969. Therefore, the preparation of an Environmental Impact Statement (EIS) is not required and BPA is issuing this FONSI.

  3. Premixed combustion of coconut oil in a hele-shaw cell

    Directory of Open Access Journals (Sweden)

    Hadi Saroso

    2014-12-01

    Full Text Available Coconut oil combustion characteristic is observed experimentally by evaporating oil in the boiler then mix it with air before being burned at various equivalence ratios in the Hele-shaw cell. The result shows that, coconut oil tends to break into glycerol and fatty acid due to hydrolysis reaction producing the flame propagation, where the fatty acid flame propagates first then glycerol flame. Micro-explosion occurs when moisture from fatty acid combustion is absorbed by glycerol and higher heating due to higher flame speed produces more micro-explosion.

  4. Pb-for-Bi substitution for enhancing thermoelectric characteristics of [(Bi,Pb)2Ba2O4+/-ω]0.5CoO2

    Science.gov (United States)

    Sakai, K.; Karppinen, M.; Chen, J. M.; Liu, R. S.; Sugihara, S.; Yamauchi, H.

    2006-06-01

    We report strongly enhanced thermoelectric characteristics for a misfit-layered oxide, [Bi2Ba2O4±ω]0.5CoO2, in a wide temperature range, as achieved through substituting up to 20% of Bi by Pb. The Pb substitution kept the thermal conductivity (κ) unchanged but decreased the electrical resistivity (ρ) and increased the Seebeck coefficient (S) simultaneously, such that a three-fold enhancement in the thermoelectric figure of merit, Z (≡S2/ρκ), was realized. At the same time x-ray absorption near-edge structure data indicated that the valence and spin states of Co are not affected by the Pb-for-Bi substitution.

  5. Influence of the cation substitution on the magnetic properties of LiCo2O4 and Li(Me,Co2O4 spinels

    Directory of Open Access Journals (Sweden)

    Gautier, J. L.

    2004-08-01

    Full Text Available Lithium-based cells LiCo2O4 have been characterized by magnetic techniques, looking at the influence of the partial substitution of cobalt by 3d or 4d transition metal elements (Fe, Ni, Cu, Cr, Mo. The non-substituted compound LiCo2O4 behaves as an antiferromagnet, with a Néel temperature TN of 30 K, although antiferromagnetic interactions are much more important, as suggested by a Weiss parameter Θ of the order of ‑225 K. In the solid solution Li(NixCo2‑xO4 the Weiss parameter Θ changes with x(Ni, reaching large positive values (e.g., Θ ~ +230 K, for x = 0.5. This phenomenon suggests the existence of a canted‑antiferromagnetic or ferrimagnetic structures with large ferromagnetic components. Substitution of cobalt by other 3d or 4d transition metals in the LiMe0.5Co1.5O4 series shows dramatic effects with respect to the non-substituted LiCo2O4 compound : copper completely suppresses the magnetic order, while iron increases TN to almost room temperature. No modifications are observed when molybdenum substitutes cobalt, while chromium transforms the AF order in a ferromagnetic one, with Tc of about 90 K.Se ha caracterizado por técnicas magnéticas, el efecto de la sustitución parcial de Co por elementos de transición 3d o 4d (Fe, Ni, Cu, Cr, Mo en celdas LiCo2O4 a base de litio. El compuesto no sustituído LiCo2O4, se comporta como un antiferromagneto de temperatura de Néel TN de 30 K, aunque existen interacciones antiferromagnéticas mucho más importantes, como lo indica un parámetro de Weiss Θ del orden de -225K. En la solución sólida Li(NixCo2‑xO4, el parámetro de Weiss Θ cambia con x(Ni, alcanzando valores positivos altos (e.g., Θ ~ +230K, para x=0.5. Este fenómeno sugiere la existencia de una estructura antiferromagnética inclinada (“AF-canted” o de una estructura ferrimagnética, donde predominan componentes ferromagnéticas importantes. La sustitución del cobalto por otros elementos de transición 3d o 4d en

  6. Synthesis of 4-substituted tetrahydropyridines by cross-coupling of enol phosphates

    DEFF Research Database (Denmark)

    Larsen, U.S.; Martiny, L.; Begtrup, M.

    2005-01-01

    Enol phosphates, synthesized from 4-piperidone, react by palladium catalyzed cross-coupling with arylboronic acids and by iron and palladium catalyzed cross-coupling with Grignard reagents to give 4-substituted tetrahydropyridines. (c) 2005 Elsevier Ltd. All rights reserved....

  7. Chlorine- and Sulphur-substituted Pyrrolo[3,4-b]quinolines and ...

    African Journals Online (AJOL)

    Chlorine- and Sulphur-substituted Pyrrolo[3,4-b]quinolines and Related Derivatives .... J. Chem., 2003, 56, 40–46,. . .... It is evident from the above that by judicious selection and application of reagents ...

  8. The synthesis of some unsaturated 4-substituted-g-lactones

    Directory of Open Access Journals (Sweden)

    SUREN HUSINEC

    2000-02-01

    Full Text Available The synthesis of conjugated and nonconjugated unsaturated 4-substituted lactones of type 1 and 2 are described. The type 1 lactone was prepared by a two step procedure employing Bredereck's reagent. The type 2 lactone was synthesised by combining the Claisen-Ireland rearrangement and selenolactonisation.

  9. Synthesis of 3-Substituted 1,4-Benzodiazepin-2-ones

    Directory of Open Access Journals (Sweden)

    Kyungjin Kim

    1998-01-01

    Full Text Available The preparation of 3-substituted 1,4-benzodiazepines by benzodiazepine enolate alkylation has been explored. Employing this approach, multigram quantities of benzodiazepine 1 have been prepared for animal studies to evaluate a new approach for the treatment of the autoimmune disease systemic lupus erythematosus (SLE.

  10. Influences of Ti4+ and Mg2+ substitutions on the properties of lithium ferrites

    International Nuclear Information System (INIS)

    Su Hua; Zhang Huaiwu; Tang Xiaoli; Liu Baoyuan

    2009-01-01

    The Ti 4+ and Mg 2+ co-substituted lithium ferrites with different compositions of Zn 0.1 Li 0.45 Mn 0.1 Fe 2.35-2x (TiMg) x O 4 (x=0.0-0.5) were prepared by the ceramic standard processing. The magnetic properties and microstructure of the samples were investigated. A single phase spinel structure was confirmed by XRD in substituting range. Sintering densities continuously decreased with the increase at x value, which was attributed to the fact that the heavier Fe 3+ ions were replaced by the relatively lighter Ti 4+ and Mg 2+ ions. However, relative density of the samples had no obvious relationship with the substituting value. Saturation magnetization continuously decreased with x value, which was attributed to the decrease of resultant magnetic moment between A and B sub-lattice. Remanence decreased monotonously with x value due to the decrease of saturation magnetization and magnetocrystalline anisotropy constant. But the effect of Ti 4+ and Mg 2+ substitutions on the Br/Bs ratio values was not obvious. Coercive force was mainly determined by the microstructure and magnetocrystalline anisotropy constant of the ferrites. In this research, with the increase of Ti 4+ and Mg 2+ substitutions, the advantageous influence by the decrease of magnetocrystalline anisotropy constant was more significant than the disadvantageous influence caused by the increase of closed pores. As a result, coercive force of the ferrites also decreased monotonously with the increase at x value.

  11. Asymmetric syntheses of 3,4-disubstituted tetrahydroquinoline derivatives using (+)- sparteine-mediated electrophilic substitution

    International Nuclear Information System (INIS)

    Choi, Yun Soo; Kang, Kyoung Hee; Park, Yong Sun

    2015-01-01

    Tetrahydroquinolines bearing substituents are frequently found as a substructure in a number of alkaloids and natural products. Since their individual stereoisomers displays different biological activities, it is desirable to develop a highly stereoselective synthetic method for tetrahydroquinolines. While some progress has recently been made toward the development of asymmetric synthetic methods for tetrahydroquinolines, it is still a challenging topic in organic synthesis. In order to investigate the source of diastereoselection attained in the substitution reaction with a racemic epoxide, we examined the substitution of 2 with an excess amount of racemic p-chlorophenyl-substituted oxirane. We have developed a novel method for the asymmetric synthesis of trans-3,4-diaryl-substituted tetrahy- droquinolines from ortho-substituted N-pivaloyl anilines. The enantioselective process includes (+)-sparteine-mediated stereoselective lithiati on, kinetic resolution of epoxides in substitution, and stereospecific Mitsu nobu cyclization as the key reactions. The simple protocol can provide highly functionalized tetrahydroqu inoline rings and would allow their further functionalization to access more complex target molecules

  12. Asymmetric syntheses of 3,4-disubstituted tetrahydroquinoline derivatives using (+)- sparteine-mediated electrophilic substitution

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Yun Soo; Kang, Kyoung Hee; Park, Yong Sun [Dept. of Chemistry, Konkuk University, Seoul (Korea, Republic of)

    2015-05-15

    Tetrahydroquinolines bearing substituents are frequently found as a substructure in a number of alkaloids and natural products. Since their individual stereoisomers displays different biological activities, it is desirable to develop a highly stereoselective synthetic method for tetrahydroquinolines. While some progress has recently been made toward the development of asymmetric synthetic methods for tetrahydroquinolines, it is still a challenging topic in organic synthesis. In order to investigate the source of diastereoselection attained in the substitution reaction with a racemic epoxide, we examined the substitution of 2 with an excess amount of racemic p-chlorophenyl-substituted oxirane. We have developed a novel method for the asymmetric synthesis of trans-3,4-diaryl-substituted tetrahy- droquinolines from ortho-substituted N-pivaloyl anilines. The enantioselective process includes (+)-sparteine-mediated stereoselective lithiati on, kinetic resolution of epoxides in substitution, and stereospecific Mitsu nobu cyclization as the key reactions. The simple protocol can provide highly functionalized tetrahydroqu inoline rings and would allow their further functionalization to access more complex target molecules.

  13. Microwave Assisted Synthesis of N-Arylheterocyclic Substituted-4-aminoquinazoline Derivatives

    Directory of Open Access Journals (Sweden)

    Ping Lu

    2006-04-01

    Full Text Available A simple, efficient, and general method has been developed for the synthesis of various N-aryl heterocylic substituted-4-aminoquinazoline compounds from 4-chloro- quinazoline and aryl heterocyclic amines under microwave irradiation using 2-propanol as solvent. The advantages of the use of microwave irradiation in relation to the classical method were demonstrated.

  14. Evaluation of sup(99m)Tc labeled amino acids as radiopharmaceuticals, 4. S-substituted cysteines and N-substituted iminodiacetic acids

    Energy Technology Data Exchange (ETDEWEB)

    Karube, Yoshiharu; Maeda, Tatsuo; Ohya, Masato; Sugata, Setsuro; Kono, Akira (Kyushu Cancer Center Research Inst., Fukuoka (Japan)); Matsushima, Yoshikazu

    1982-06-01

    Sixteen sup(99m)Tc labeled ligands were evaluated as scintigraphic agents. The ligands studied were cysteine, glutathione, their S-substituted derivatives, lysine-N sup(epsilon), N sup(epsilon)-diacetic acid, glycylglycine-N,N-diacetic acid, glycylglycylglycine-N,N-diacetic acid, taurine-N,N-diacetic acid, hydrazine-N,N-diacetic acid, ethylenediamine-N,N-diacetic acid, and propylne-1,3-diamine-N/sup 1/-,N/sup 1/-diacetic acid. The ligands were labeled with sup(99m)Tc by the SnCl/sub 2/ method with more than 95% yield. The in vivo behavior of the sup(99m)Tc labeled ligands were studied in golden hamsters and dogs. The organ distribution in golden hamsters indicated clearance both by hepatobiliary and renal systems. The pancreas/blood ratios were much lower in the sup(99m)Tc ligands than in /sup 75/Se-selenomethionine. Scintigraphic studies in dogs showed that the liver and kidneys were well visualized but the accumulation by the pancreas was not sufficient for clear visualization.

  15. Bioaerosol concentrations - Figure 3 and Figure 4

    Data.gov (United States)

    U.S. Environmental Protection Agency — Bioaerosol concentrations. This dataset is associated with the following publication: Chattopadhyay, S., S. Perkins, M. Shaw, and T. Nichols. Evaluation of Exposure...

  16. The features of nucleophilic substitution of the nitro group in 4-alkyl-6-nitro-1,2,4-triazolo[5,1-c][1,2,4]triazines

    Directory of Open Access Journals (Sweden)

    E. N. Ulomsky

    2017-05-01

    Full Text Available The nucleophilic substitution of the nitro group of 4-alkyl-6-nitro-4,7-dihydro-1,2,4-triazolo[5,1-c][1,2,4]triazine-7-ones on the example of interactionwith morpholine was studied. It is established that under the action of excess cycloalkylimine at room temperature the unusual easy disclosure of triazine cycle with the formation of sterically hindered hydrazones occurs which are the key intermediates for further transformations. The carrying of reaction at elevated temperatures leads to the formation of products of substitution of the nitro group with the amine and also with morpholyl hydrazones which are the products of hydrolysis of amides of hydrazones and subsequent decarboxylation. Thus, the nucleophilic substitution of the nitro group in the described triazolotriazines flows through the ANRORC mechanism.

  17. Numerical simulation of particle jet formation induced by shock wave acceleration in a Hele-Shaw cell

    Science.gov (United States)

    Osnes, A. N.; Vartdal, M.; Pettersson Reif, B. A.

    2018-05-01

    The formation of jets from a shock-accelerated cylindrical shell of particles, confined in a Hele-Shaw cell, is studied by means of numerical simulation. A number of simulations have been performed, systematically varying the coupling between the gas and solid phases in an effort to identify the primary mechanism(s) responsible for jet formation. We find that coupling through drag is sufficient for the formation of jets. Including the effect of particle volume fraction and particle collisions did not alter the general behaviour, but had some influence on the length, spacing and number of jets. Furthermore, we find that the jet selection process starts early in the dispersal process, during the initial expansion of the particle layer.

  18. /sup 13/C NMR spectra and electron conduction in 4-substituted diphenylamines

    Energy Technology Data Exchange (ETDEWEB)

    Filimonov, V.D.; Kogan, R.M.; Tverdokhlebova, N.E.; Shcherbakov, V.V.; Kushnarev, D.F.; Kalabin, G.A.

    1986-07-10

    The /sup 13/C NMR spectra were recorded for a series of 4-X-diphenylamines, and correlations equations relating the /sup 13/C NMR chemical shifts of the C/sup 1/ and C/sup 4/ positions to the electronic characteristics of the substituent X were obtained. It was established that the conduction of the substituted ring in the 4-X-diphenylamines is practically the same as in 4-X-biphenyls. Joint analysis of the spectral characteristics of the diphenylamines, biphenyls, N-substituted anilines, and carbazoles made it possible to conclude that the increased transmission characteristics of the diphenylamines are determined by the conformational mobility of the two benzene rings and by the unidirectional effect of changes in the introduction and resonance factors with variation in the substituent X.

  19. An assembly of steadily translating bubbles in a Hele–Shaw channel

    International Nuclear Information System (INIS)

    Crowdy, Darren

    2009-01-01

    This paper presents new solutions for any finite number of bubbles steadily translating along a Hele–Shaw channel. This constitutes a nonlinear free boundary problem. The solutions can be written down explicitly in terms of a special transcendental function called the Schottky–Klein prime function. This work generalizes the exact solutions for a single bubble in a channel found by Tanveer (1987 Phys. Fluids 30 651–8) as well as the solutions for streams of bubbles aligned along the channel centreline due to Vasconcelos (1994 Phys. Rev. E 50 R3306–9)

  20. A-site substitution effect of strontium on bismuth layered CaBi{sub 4}Ti{sub 4}O{sub 15} ceramics on electrical and piezoelectric properties

    Energy Technology Data Exchange (ETDEWEB)

    Tanwar, Amit, E-mail: amit07tanwar@gmail.com [Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India); Verma, Maya; Gupta, Vinay; Sreenivas, K. [Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India)

    2011-10-17

    Strontium substituted CaBi{sub 4}Ti{sub 4}O{sub 15} ceramics with the chemical formula Ca{sub 1-x}Sr{sub x}Bi{sub 4}Ti{sub 4}O{sub 15} (CSBT) (x = 0.0-1.0) have been prepared through conventional solid state route. The formation of single phase material with orthorhombic structure was verified from X-ray diffraction with incorporation of Sr substitution. Decrease in a-axis displacement of Bi ion in the perovskite structure in the CSBT ceramics were observed from the relative changes in soft mode (20 cm{sup -1}) in the Raman spectra, and increase in Sr incorporation shows the shift in ferroelectric to paraelectric phase transition temperature. The dielectric properties for all the CSBT ceramic compositions are studied as a function of temperature over the frequency range of 100 Hz-1 MHz. Curie's temperature was found to be function of Sr substitution and with increase in the Sr concentration the phase transition becomes sharper and phase transition temperature gets shifted towards lower temperature (790-545 deg. C). The behavior of ac conductivity as a function of frequency (100 Hz-1 MHz) at low temperature (<500 deg. C) follows the power law and attributed to hopping conduction mechanism. Sr substitution results in the increase in piezoelectric coefficients (d{sub 33}) whereas piezoelectric charge coefficient values were found comparable to that of PZT at room temperature. Relative changes in soft modes due to Sr incorporation results in high piezoelectricity in the CSBT ceramics.

  1. Anti-inflammatory and antinociceptive evaluation of newly synthesized 4-(substituted ethanoyl amino-3-mercapto-5-(4-methoxy phenyl-1,2,4-triazoles

    Directory of Open Access Journals (Sweden)

    Neeraj Upmanyu

    2011-01-01

    of oedema especially 6k exhibiting a percentage of oedema inhibition of 40.28%, which was comparable to that of the standard drug indomethacin (62.50% at 10mg/kg dose. Among the compounds tested, compound 6k exhibited good anti-nociceptive activity in both methods used. Pethidine (20mg/kg body weight s.c is used as the standard drug. Conclusion: SAR of these synthesized compounds shows that substitution with heterocyclic moiety at C-2 of the acetamido group at position 4 of the 1,2,4-triazole produces appreciable activity as compared to substitution with aliphatic moieties since among all the synthesized compounds, the most active ones are 6f, 6i and 6k that have piperdine, 1-benzyl piperazine and morpholine group, respectively at C-2 of the acetamido group at position 4 of the 1,2,4-triazole.

  2. Genealogy of John and Charles Bell: their relationship with the children of Charles Shaw of Ayr.

    Science.gov (United States)

    Kaufman, M

    2005-11-01

    The Reverend William Bell had six children who survived infancy. Two of his sons entered the legal profession and two other sons became distinguished anatomists and surgeons--John Bell, said for 20 years to have been the leading operating surgeon in Britain and throughout the world--and Sir Charles Bell, possibly the most distinguished anatomist and physiologist of his day. Information is not known about the fifth son or their sister. Charles Shaw, a lawyer of Ayr, had four sons and two daughters who survived infancy. Two of his sons, John and Alexander, became anatomists and later surgeons at the Middlesex Hospital, and both worked closely with Charles Bell at the Great Windmill Street School of Anatomy. His third son entered the law and his fourth son became a distinguished soldier. The two daughters of Charles Shaw married into the Bell family: Barbara married George Joseph Bell and Marion married Mr (later Sir) Charles Bell.

  3. 8 CFR 246.4 - Immigration judge's authority; withdrawal and substitution.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Immigration judge's authority; withdrawal... IMMIGRATION REGULATIONS RESCISSION OF ADJUSTMENT OF STATUS § 246.4 Immigration judge's authority; withdrawal and substitution. In any proceeding conducted under this part, the immigration judge shall have...

  4. Electronic structure and photocatalytic activity of wurtzite Cu–Ga–S nanocrystals and their Zn substitution

    KAUST Repository

    Kandiel, Tarek

    2015-03-23

    Stoichiometric and gallium-rich wurtzite Cu-Ga-S ternary nanocrystals were synthesized via a facile solution-based hot injection method using 1-dodecanethiol as a sulfur source. The use of 1-dodecanethiol was found to be essential not only as a sulfur source but also as a structure-directing reagent to form a metastable wurtzite structure. In addition, the substitution of zinc in the wurtzite gallium-rich Cu-Ga-S nanocrystals was also investigated. The obtained nanocrystals were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), diffuse reflectance spectroscopy (DRS), photoluminescence (PL), and inductively coupled plasma atomic emission spectroscopy (ICP-OES). Electronic structures of pristine and the Zn-substituted Cu-Ga-S system were investigated using density functional theory (DFT) with HSE06 exchange-correlation functional. The calculated bandgaps accurately reflect the measured ones. The allowed electronic transitions occur upon the photon absorption from the (Cu + S) band towards the (Ga + S) one. The Zn substitution was found not to contribute to the band edge structure and hence altered the bandgaps only slightly, the direct transition nature remaining unchanged with the Zn substitution. The photocatalytic activities of H2 evolution from an aqueous Na2S/Na2SO3 solution under visible-light illumination on the synthesized nanocrystals were investigated. While the stoichiometric CuGaS2 exhibited negligible activity, the gallium-rich Cu-Ga-S ternary nanocrystals displayed reasonable activity. The optimum Zn substitution in the gallium-rich Cu-Ga-S ternary nanocrystals enhanced the H2 evolution rate, achieving an apparent quantum efficiency of >6% at 400 nm. © 2015 The Royal Society of Chemistry.

  5. Bubble extinction in Hele-Shaw flow with surface tension and kinetic undercooling regularization

    International Nuclear Information System (INIS)

    Dallaston, Michael C; McCue, Scott W

    2013-01-01

    We perform an analytic and numerical study of an inviscid contracting bubble in a two-dimensional Hele-Shaw cell, where the effects of both surface tension and kinetic undercooling on the moving bubble boundary are not neglected. In contrast to expanding bubbles, in which both boundary effects regularize the ill-posedness arising from the viscous (Saffman–Taylor) instability, we show that in contracting bubbles the two boundary effects are in competition, with surface tension stabilizing the boundary, and kinetic undercooling destabilizing it. This competition leads to interesting bifurcation behaviour in the asymptotic shape of the bubble in the limit it approaches extinction. In this limit, the boundary may tend to become either circular, or approach a line or ‘slit’ of zero thickness, depending on the initial condition and the value of a nondimensional surface tension parameter. We show that over a critical range of surface tension values, both these asymptotic shapes are stable. In this regime there exists a third, unstable branch of limiting self-similar bubble shapes, with an asymptotic aspect ratio (dependent on the surface tension) between zero and one. We support our asymptotic analysis with a numerical scheme that utilizes the applicability of complex variable theory to Hele-Shaw flow. (paper)

  6. Universality Results for Multi-phase Hele-Shaw Flows

    Science.gov (United States)

    Daripa, Prabir

    2013-03-01

    Saffman-Taylor instability is a well known viscosity driven instability of an interface separating two immiscible fluids. We study linear stability of displacement processes in a Hele-Shaw cell involving an arbitrary number of immiscible fluid phases. This is a problem involving many interfaces. Universal stability results have been obtained for this multi-phase immiscible flow in the sense that the results hold for arbitrary number of interfaces. These stability results have been applied to design displacement processes that are considerably less unstable than the pure Saffman-Taylor case. In particular, we derive universal formula which gives specific values of the viscosities of the fluid layers corresponding to smallest unstable band. Other similar universal results will also be presented. The talk is based on the following paper. This work was supported by the Qatar National Research Fund (a member of The Qatar Foundation).

  7. Computational Study on Substituted s-Triazine Derivatives as Energetic Materials

    Directory of Open Access Journals (Sweden)

    Vikas D. Ghule

    2012-01-01

    Full Text Available s-Triazine is the essential candidate of many energetic compounds due to its high nitrogen content, enthalpy of formation and thermal stability. The present study explores s-triazine derivatives in which different -NO2, -NH2 and -N3 substituted azoles are attached to the triazine ring via C-N linkage. The density functional theory is used to predict geometries, heats of formation and other energetic properties. Among the designed compounds, -N3 derivatives show very high heats of formation. The densities for designed compounds were predicted by using the crystal packing calculations. Introduction of -NO2 group improves density as compared to -NH2 and -N3, their order of increasing density can be given as NO2>N3>NH2. Analysis of the bond dissociation energies for C-NO2, C-NH2 and C-N3 bonds indicates that substitutions of the -N3 and -NH2 group are favorable for enhancing the thermal stability of s-triazine derivatives. The nitro and azido derivatives of triazine are found to be promising candidates for the synthetic studies.

  8. The 4.5 S RNA gene of Escherichia coli is essential for cell growth

    DEFF Research Database (Denmark)

    Brown, S; Fournier, M J

    1984-01-01

    The Escherichia coli gene coding for the metabolically stable 4.5 S RNA (ffs) has been shown to be required for cell viability. Essentiality was demonstrated by examining the recombination behavior of substitution mutations of ffs generated in vitro. Substitution mutants of ffs are able to replace...... the chromosomal allele only in the presence of a second, intact copy of ffs. Independent evidence of essentiality and the finding that 4.5 S RNA is important for protein synthetic activity came from characterization of cells dependent on the lac operon inducer isopropyl-beta-D-thiogalactoside for ffs gene...... expression. Here, a strain dependent on isopropyl-beta-D-thiogalactoside for 4.5 S RNA synthesis was developed by inactivation of the chromosomal ffs allele and lysogenization by a lambda phage containing 4.5 S DNA fused to a hybrid trp-lac promoter. Withdrawal of the thiogalactoside leads to a deficiency...

  9. Amino acid derived 1,4-dialkyl substituted imidazolones

    DEFF Research Database (Denmark)

    Diness, Frederik; Meldal, Morten Peter

    2010-01-01

    A general method for synthesis of 1,4-substituted imidazolones from amino acids on solid support or in solution has been developed. Amino acid derived 3-Boc-(1,3)-oxazinane (Box) protected amino aldehyde building blocks were coupled through urea bonds to the amino terminal of dipeptides or amino...... acids. Upon acidic release, the aldehyde instantaneously formed the cyclic N-carbamyliminium ion, which rearranged to the corresponding imidazolone. Under strongly acidic conditions the imidazolones acted as nuclophiles in the Pictet-Spengler reaction....

  10. Cation ordering in orthopyroxenes and cooling rates of meteorites: Low temperature cooling rates of Estherville, Bondoc and Shaw

    Science.gov (United States)

    Ganguly, J.; Yang, H.; Ghose, S.

    1993-01-01

    The cooling rates of meteorites provide important constraints on the size of their parent bodies, and their accretionary and evolutionary histories. However, the cooling rates obtained so far from the commonly used metallographic, radiometric and fission-track methods have been sometimes quite controversial, such as in the case of the mesosiderites and the meteorite Shaw. We have undertaken a systematic study of the cooling rates of meteorites using a different approach, which involves single crystal x-ray determination of Fe(2+)-Mg ordering in orthopyroxenes (OP(x)) in meteorites, subject to bulk compositional constraints, and numerical simulation of the evolution of the ordering state as a function of cooling rate, within the framework of the thermodynamic and kinetic principles governing cation ordering. We report the results obtained for OP(x) crystals from Shaw and two mesosiderites, Estherville and Bondoc.

  11. Tetrakis(4-tert-butylphenyl) substituted and fused quinoidal porphyrins

    KAUST Repository

    Zeng, Wangdong

    2012-01-01

    4-tert-Butylphenyl-substituted and fused quinoidal porphyrins 1 and 2 are prepared for the first time. They show (1) intense one-photon absorption in the far-red/near-infrared region, (2) enhanced two-photon absorption compared with aromatic porphyrin monomers, and (3) amphoteric redox behavior. Their geometry and electronic structure are studied by DFT calculations. This journal is © 2012 The Royal Society of Chemistry.

  12. Selective biotransformation of substituted alicyclic nitriles by Rhodococcus equi A4

    Czech Academy of Sciences Publication Activity Database

    Martínková, Ludmila; Klempier, N.; Preiml, M.; Ovesná, Mária; Kuzma, Marek; Mylerová, Veronika; Křen, Vladimír

    2002-01-01

    Roč. 80, - (2002), s. 724-727 ISSN 0008-4042 R&D Projects: GA ČR GA524/00/1275; GA AV ČR IAA4020802 Keywords : nitrile hydratase * substituted cyclohexanecarbonitriles * cyclopentanecarbonitriles Subject RIV: EE - Microbiology, Virology Impact factor: 1.260, year: 2002

  13. Phase evaluation of Li{sup +} substituted CoFe{sub 2}O{sub 4} nanoparticles, their characterizations and magnetic properties

    Energy Technology Data Exchange (ETDEWEB)

    Kadam, R.H. [Materials Science Research Lab, Shrikrishna Mahavidyalaya Gunjoti, Osmanabad, Maharashtra (India); Alone, Suresh T. [Department of Physics, RS Art' s, Science and Commerce College, Pathri, Aurangabad, Maharashtra (India); Mane, Maheshkumar L. [Department of Physics, Rajarshi Shahu Mahavidyalaya, Latur, Maharashtra (India); Biradar, A.R. [Materials Science Research Lab, Shrikrishna Mahavidyalaya Gunjoti, Osmanabad, Maharashtra (India); Shirsath, Sagar E., E-mail: shirsathsagar@hotmail.com [Spin Device Technology Center, Department of Information Engineering, Shinshu University, Nagano 380-8553 (Japan)

    2014-04-15

    Li{sup +} substituted CoFe{sub 2}O{sub 4} with the chemical formula Li{sub 3x}CoFe{sub 2−x}O{sub 4} were synthesized by sol–gel auto combustion method. The synthesized samples were annealed at 600 °C for 4 h. X-ray diffraction data were used to evaluate the structure of the prepared samples. Spinel ferrite phase of CoFe{sub 2}O{sub 4} changes to ordered like lithium ferrite phase with increase in L{sup i+} substitution. Lattice constant increases whereas particle size found to decrease with Li{sup +} substitution. Infrared spectroscopy also confirmed the phase transition of CoFe{sub 2}O{sub 4} after the incorporation of lithium ions. Substitution of Li{sup +} ions for Fe{sup 3+} caused a decrease in the saturation magnetization from 69.59 emu/g to 47.71 emu/g and the coercivity increased from 647 Oe to 802 Oe. Resistivity and dielectric properties shows inverse relation to each other. - Highlights: • Li{sup +} ion substituted CoFe{sub 2}O{sub 4}. • Single phase cubic spinel structure changes with Li{sup +} substitution. • Magnetization decreases whereas coercivity increases with increasing Li{sup +}. • Resistivity decreases with Li{sup +} substitution.

  14. Effect of 2-methyl-substituted nitroimidazoles on the hydrolysis of 4-nitrophenyl esters. Suffield report

    Energy Technology Data Exchange (ETDEWEB)

    Clewley, R.G.; Adie, C.P.; Brouwer, B.H.

    1994-03-01

    Prior to investigating nitroimidazole surfactants for use in a new catalytic chemical agent decontaminant, the catalysis afforded by simple nitroimidazoles in hydrolysis reactions has been examined. The effect of 2-methyl-5-nitroimidazole on the hydrolysis of 4-nitrophenyl diphenylphosphinate and of 2-methyl-5-nitrobenzimidazole on the hydrolyses of both 4-nitrophenyl diphenylphosphinate and 4-nitrophenyl acetate has been determined. In all three cases there is a simple linear dependency of the reaction rate on the concentration of the anionic form of the nitroimidazole. Previous results had suggested self-inhibition by the nucleophile occurred in the 2-methyl-5-nitroimidazole catalysed hydrolysis of 4-nitrophenyl diphenylphosphinate; this hypothesis is no longer tenable. Comparison of the reactivity of 2-methyl -substituted nitroimidazolides to that of the corresponding unsubstituted species suggests that 2-alkyl-substituted nitroionidazole surfactants would not be significantly worse catalysts of the hydrolysis of organophosphorus species than their 4-substituted analogues. Decontamination, Chemical reactivity, Displacement reactions, Nucleophilic reactions, Imidazoles, Nitroimidazoles, Phenoxides, Simulants, UV Spectrophotometry, Mechanism.

  15. Narsisisme dan Kompleks Oedipus yang Tergambar dalam Pygmalion, Karya George Bernard Shaw

    Directory of Open Access Journals (Sweden)

    Essy Syam

    2017-06-01

    Full Text Available Abstract This writing analyzes narcisism and oedipuis complex as refelcted in a literary work entitles “pygmalion” written by George Bernard Shaw. Thus, the objective of this analysis is to show and to analyze how narcisism and Oedipus complex are suffered from the protagonist of this work. To reach that objective, this analysis applies psychoanalitical analysis  to demonstrate the mental condition of the main character. Related to that idea, this analysis applies adescriptive analysis method in which the result of the analysis will be described clearly. From teh presented description, it will show how the main character of this work lives his life and in his interaction with other characters will describe his mental condition.   Keywords: Pygmalion, psychoanalisis, Narcisism, Oedipus Complex.    Abstrak Tulisan ini menganalisis kasus Narsisme dan Kompleks Oedipus yang tergambar pada sebuah karya sastra berjudul Pygmalion yang ditulis oleh George  Bernard Shaw.  Maka tujuan penelitian ini adalah untuk memperlihatkan dan menganalisis bagaimana kasus narsisme dan kompleks oedipus yang dialami oleh tokoh utama karya ini. Untuk mencapai tujuan itu, kajian ini menerapkan kajian psikoanalisis  untuk memperlihatkan kondisi kejiwaan tokoh utama yang mengalami gangguan jiwa yang dimanakan Narsisime dan Kompleks Oedipus.  Kajian ini menerapkan metode deskriptif analisis dimana hasil analisis akan dideskripsikan dengan jelas. Dari deskripsi yang dijabarkan akan memperlihatkan bagaimana tokoh utama karya ini dalam kehidupannya dan interaksinya dengan tokoh yang lain memperlihatkan kondisi jiwanya.   Kata Kunci: Pygmalion, Psikoanalisis. Narsisime, Kompleks Oedipus

  16. Energy substitution in oil-exporting LDC's the Indonesian experience

    Energy Technology Data Exchange (ETDEWEB)

    Rose, A.; Soelistijo, U. (Pennsylvania State University, University Park (USA). Dept. of Mineral Economics)

    1989-02-01

    Many oil-exporting LDCs defy the stereotype of an OPEC country with an excess of oil reserves for current and future needs. In this paper it is suggested that serious consideration be given to the substitution of other fossil energy resources for oil used domestically in order to release more oil for export. This will generate more foreign exchange and extend the life of the reserve base. A coal-oil substitution programme for Indonesia is presented and analysed to illustrate the economic development benefits of this strategy. 11 refs., 1 fig., 4 tabs.

  17. Universality Results for Multi-layer Radial Hele-Shaw Flows

    Science.gov (United States)

    Daripa, Prabir; Gin, Craig; Daripa Research Team

    2014-03-01

    Saffman-Taylor instability is a well known viscosity driven instability of an interface separating two immiscible fluids. We study linear stability of this displacement process in multi-layer radial Hele-Shaw geometry involving an arbitrary number of immiscible fluid phases. Universal stability results have been obtained and applied to design displacement processes that are considerably less unstable than the pure Saffman-Taylor case. In particular, we derive universal formula which gives specific values of the viscosities of the fluid layers corresponding to smallest unstable band. Other similar universal results will also be presented. The talk is based on ongoing work. Supported by an NPRP Grant # 08-777-1-141 from the Qatar National Research Fund (a member of the Qatar Foundation). The statements made herein are solely the responsibility of the authors.

  18. Shocks and finite-time singularities in Hele-Shaw flow

    Energy Technology Data Exchange (ETDEWEB)

    Teodorescu, Razvan [Los Alamos National Laboratory; Wiegmann, P [UNIV OF MONTREAL; Lee, S-y [UNIV OF CHICAGO

    2008-01-01

    Hele-Shaw flow at vanishing surface tension is ill-defined. In finite time, the flow develops cusplike singularities. We show that the ill-defined problem admits a weak dispersive solution when singularities give rise to a graph of shock waves propagating in the viscous fluid. The graph of shocks grows and branches. Velocity and pressure jump across the shock. We formulate a few simple physical principles which single out the dispersive solution and interpret shocks as lines of decompressed fluid. We also formulate the dispersive solution in algebro-geometrical terms as an evolution of Krichever-Boutroux complex curve. We study in details the most generic (2,3) cusp singularity which gives rise to an elementary branching event. This solution is self-similar and expressed in terms of elliptic functions.

  19. Three dimensional vortices and interfaces in Hele-Shaw cells

    International Nuclear Information System (INIS)

    Pumir, A.

    1987-06-01

    A model of nonviscous flow, based on the Biot-Savart equations is used to examine the existence of singularities in three dimensional, incompressible, hydrodynamic equations. The results suggest a fairly simple physical mechanism, which could lead to the formation of singularities in the nonviscous case: two vortex tubes with opposite circulations pair up and stretch each other, until the radii of the vortex cores become extremely small, causing a divergence of the vorticity. The cases of a perfect and a slightly viscous fluid are considered. The results are unclear as to whether the vorticity of a slightly viscous fluid can become infinite or not, and whether singularities exist. The dynamics of hydrodynamic interfaces are also investigated. The propagation of bubbles in a slightly viscous fluid, in a Hele-Shaw cell are described [fr

  20. The angle of repose of spherical grains in granular Hele–Shaw cells: a molecular dynamics study

    International Nuclear Information System (INIS)

    Maleki, Hamed; Ebrahimi, Fatemeh; Oskoee, Ehsan Nedaaee

    2008-01-01

    We report the results of three-dimensional molecular dynamic simulations on the angle of repose of a sandpile formed by pouring mono-sized cohesionless spherical grains into a granular Hele–Shaw cell. In particular, we are interested in investigating the effects of those variables which may have a significant impact on the pattern formation of granular mixtures in Hele–Shaw cells. The results indicate that the frictional forces influence the formation of piles on the grain level remarkably. Furthermore, we see that increasing grain insertion rate decreases the angle of repose slightly. We also find that the cell thickness is a significant factor and the angle of repose decays when the size of the gap between the lateral walls increases. In addition to agreeing with the experimental exponential decay law, our results are in accordance with a recently proposed model which takes into account the arching effects. Using grains with different sizes reveals that the behaviour of the angle of repose when both size and cell thickness are varied is controlled by a scaled function of the ratio of these two variables

  1. Droplet formation in Hele-Shaw T-junction.

    Science.gov (United States)

    Ricouvier, Joshua; Yazhgur, Pavel; Leshansky, Alexander; Tabeling, Patrick; Microflusa Team

    The development of digital microfluidics has attracted considerable interest towards generation of highly monodisperse microdroplets. T-junction has become an essential element of most of microfluidic chips. Despite its importance, theoretical analysis of droplet formation at T-junction is still incomplete due to complexity of physics involved. We focused on droplet generation at the Hele-Shaw T-junction. The effect of various experimental parameters, such as channel geometry, flow rates, surface tension and fluid viscosities, was thoroughly investigated. Our results show that the experimental system exhibits three distinct regimes (squeezing, dripping and jetting regimes) and point out the effect of confinement on the transitions. We demonstrate that the size of the ''plug'' droplet depends not only on the flow rate ratio (as described in the literature), but also on the capillary number and the channel cross-section aspect ratio. Quasi-2D flow equations allow us to perform numerical simulations and to compare them with experimental results. The Microflusa project receives funding from the European Union's Horizon 2020 research and innovation programme under Grant Agreement No. 664823.

  2. Of mice and men: evolution and the socialist utopia. William Morris, H.G. Wells, and George Bernard Shaw.

    Science.gov (United States)

    Hale, Piers J

    2010-01-01

    During the British socialist revival of the 1880s competing theories of evolution were central to disagreements about strategy for social change. In News from Nowhere (1891), William Morris had portrayed socialism as the result of Lamarckian processes, and imagined a non-Malthusian future. H.G. Wells, an enthusiastic admirer of Morris in the early days of the movement, became disillusioned as a result of the Malthusianism he learnt from Huxley and his subsequent rejection of Lamarckism in light of Weismann's experiments on mice. This brought him into conflict with his fellow Fabian, George Bernard Shaw, who rejected neo-Darwinism in favour of a Lamarckian conception of change he called "creative evolution."

  3. Electrokinetic Fingering In Hele-Shaw Cells

    Science.gov (United States)

    Mirzadeh, Mohammad; Bazant, Martin

    2016-11-01

    Large scale flow problems in porous media, such as those encountered in underground oil reservoirs, are typically described by the Darcy's law. However, it is well known that many underground rock formations contain surface groups and minerals that dissociate in the presence of water. Convection of these charges by the pressure driven flow can then set up streaming current and streaming potential that affects the flow. Furthermore, electric fields that are often used to enhance oil recovery, e.g. by reducing the oil's viscosity through electro-thermal heating, drive electro-osmotic flows that could set up very large pressure in small pores. The full description of fluid flow thus requires a solution to the fully coupled electrokinetic problem. In their seminal work, Saffman and Taylor showed that the moving interface between two immiscible fluids in a porous medium becomes unstable if pushed by the low-viscosity fluid. Here we report on the role of electrokinetic phenomena on stability of these viscous fronts in Hele-Shaw cells by using analytic as well as numerical approaches. Interestingly, we find that the instability could be suppressed if the right physical conditions are met or otherwise enhanced, leading to greater mixing of two fluids.

  4. Cr-substituted LiCoPO4 core with a conductive carbon layer towards high-voltage lithium-ion batteries

    Science.gov (United States)

    Wang, Yue; Chen, Junhong; Qiu, Jingyi; Yu, Zhongbao; Ming, Hai; Li, Meng; Zhang, Songtong; Yang, Yusheng

    2018-02-01

    Electrical and ionic conductivity are two major limiting factors for LiCoPO4 cathode material. To overcome these shortcomings, a Cr-substituted LiCoPO4 core with a conductive carbon layer cathode material is synthesized using the sol-gel method. The physical chemistry properties of these materials are systematically investigated by using various characterization methods. For instance, the XRD and Rietveld refinement results reveal that Cr successfully substitutes the Co within the LiCoPO4 core to form LiCo1-1.5xCrxPO4/C (x = 0, 0.02, 0.04, 0.06) without changing the olivine structure but exhibits a decrease in the unit cell volume with increasing Cr substitution. SEM and TEM images indicate that Cr substitution does not lead to changes in the basic morphology of LiCo1-1.5xCrxPO4/C (x = 0, 0.02, 0.04, 0.06) material, which is composed of agglomerated nanoparticles with an 8 nm carbon layer on the surface. The EDS and XPS results confirm that Cr is uniformly distributed on the surface and that the oxidation state of Cr is +3. FTIR spectra indicate that the antisite defect concentration decreases with increasing Cr substitution. Furthermore, Cr substitution significantly improves the electrochemical performances of LiCo1-1.5xCrxPO4/C (x = 0.02, 0.04, 0.06) cathode. Notably, the LiCo0.94Cr0.04PO4/C delivers an initial discharge capacity of 144 mA h g-1 at 0.1 C and shows a capacity retention of 71% after 100 cycles between 3.0 and 5.0 V. The CV and EIS results indicate that the polarization is reduced and that the electronic and ionic conductivities are improved by Cr substitution. The good electrochemical performances for Cr-substituted LiCoPO4/C electrodes are attributed to the lower antisite defect concentration, as the reduction of polarization, the improvement of electronic and ion conductivity and the uniform carbon layer. These features will accelerate the commercial application of LiCoPO4 towards the start-art of the high voltage lithium-ion batteries.

  5. Environmental Assessment for Wing Infrastructure Development Outlook (WINDO) Plan Shaw Air Force Base, South Carolina

    Science.gov (United States)

    2004-10-01

    officially established on August 30, 1941 and was named after 1st Lt. Ervin D. Shaw, a Sumter County resident who was killed in action during World War I...Examples of the animal species likely to occur within this community include the cottontail, mockingbird , American robin, and crow. At the Poinsett...include the white-tailed deer, red fox, raccoon, opossum, striped skunk, cottontail, meadowlark, mockingbird , American kestrel, fence lizard, and

  6. S1 constrains S4 in the voltage sensor domain of Kv7.1 K+ channels.

    Directory of Open Access Journals (Sweden)

    Yoni Haitin

    Full Text Available Voltage-gated K(+ channels comprise a central pore enclosed by four voltage-sensing domains (VSDs. While movement of the S4 helix is known to couple to channel gate opening and closing, the nature of S4 motion is unclear. Here, we substituted S4 residues of Kv7.1 channels by cysteine and recorded whole-cell mutant channel currents in Xenopus oocytes using the two-electrode voltage-clamp technique. In the closed state, disulfide and metal bridges constrain residue S225 (S4 nearby C136 (S1 within the same VSD. In the open state, two neighboring I227 (S4 are constrained at proximity while residue R228 (S4 is confined close to C136 (S1 of an adjacent VSD. Structural modeling predicts that in the closed to open transition, an axial rotation (approximately 190 degrees and outward translation of S4 (approximately 12 A is accompanied by VSD rocking. This large sensor motion changes the intra-VSD S1-S4 interaction to an inter-VSD S1-S4 interaction. These constraints provide a ground for cooperative subunit interactions and suggest a key role of the S1 segment in steering S4 motion during Kv7.1 gating.

  7. Tsunakawa-Shaw method - an absolute paleointensity technique using alternating field demagnetization

    Science.gov (United States)

    Yamamoto, Y.; Mochizuki, N.; Shibuya, H.; Tsunakawa, H.

    2015-12-01

    Among geologic materials volcanic rocks have been typically used to deduce an absolute paleointensity. In the last decade, however, there seems a becoming consensus that volcanic rocks are not so ideal materials due to such as magnetic grains other than non-interacting single domain particles. One approach to obtain a good paleointensity estimate from the rocks is to reduce and correct the non-ideality, suppress alterations in laboratory and screen out suspicious results. We have been working on a development and an application of the Tsunakawa-Shaw method, which has been previously called the LTD-DHT Shaw method. This method is an AF(alternating field)-based technique and thus a paleointensity is estimated using coercivity spectra. To reduce the non-ideality, all remanences undergo low-temperature demagnetization (LTD) before any AF demagnetizations to remove multi-domain like component. To correct the non-ideality, anhysteretic remanent magnetizations (ARMs) are imparted with their directions parallel to natural remanent magnetizations and laboratory-imparted thermoremanent magnetizations (TRMs) and measured before and after laboratory heating. These ARMs are used to correct remanence anisotropies, possible interaction effects originated from the non-ideal grains and TRM changes caused by laboratory alterations. TRMs are imparted by heating specimens above their Curie temperatures and then cooling to room temperature at once to simulate nature conditions. These cycles are done in vacuum to suppress alterations in laboratory. Obtained results are judged by selection criteria, including a check for validity of the ARM corrections.It has been demonstrated that successful paleointensities are obtained from historical lavas in Japan and Hawaii, and from baked clay samples from a reconstructed ancient kiln, with the flow-mean precision of 5-10%. In case of old volcanic rocks, however, the method does not necessarily seem to be perfect. We will summarize these points in

  8. Design, synthesis and anticonvulsant activity evaluation of 7-substituted-4H-[1,2,4]triazino[3,4-alpha]phthalazin-4-one derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Xian-Yu; Quan, Zhe-Shan [Yanbian Univ., Yanji, Jilin (China). Key Lab. of Organism Functional Factors of the Changbai Mountain; Yanbian Univ., Yanji, Jilin (China). Coll. of Pharmacy; Guan, Li-Ping; Zhang, Lei; Wei, Cheng-Xi; Piao, Hu-Ri [Yanbian Univ., Yanji, Jilin (China). Key Lab. of Organism Functional Factors of the Changbai Mountain

    2009-07-01

    In this study, a novel series of 7-substituted-4H-[1,2,4]triazino[3,4-a]phthalazin-4-one derivatives was synthesized as potential anticonvulsant agents. Their anticonvulsant activities were evaluated by the maximal electroshock (MES) test, and their neurotoxicities were evaluated by the rotarod neurotoxicity test. The pharmacological results showed that 7-hexyloxy-4H-[1,2,4]triazino[3,4-alpha]phthalazin-4-one 4e was the most potent with median effective dose (ED{sub 50}) value of 6.6 mg kg-1, median toxicity dose (TD{sub 50}) of 39.4 mg kg{sup -1}, providing a protective index (PI=TD{sub 50} /ED{sub 50}) value of 6.0. (author)

  9. A tandem Mannich addition–palladium catalyzed ring-closing route toward 4-substituted-3(2H-furanones

    Directory of Open Access Journals (Sweden)

    Jubi John

    2014-06-01

    Full Text Available A facile route towards highly functionalized 3(2H-furanones via a sequential Mannich addition–palladium catalyzed ring closing has been elaborated. The reaction of 4-chloroacetoacetate esters with imines derived from aliphatic and aromatic aldehydes under palladium catalysis afforded 4-substituted furanones in good to excellent yields. 4-Hydrazino-3(2H-furanones could also be synthesized from diazo esters in excellent yields by utilising the developed strategy. We could also efficiently transform the substituted furanones to aza-prostaglandin analogues.

  10. Effect of La-substitution on the structure and dielectric properties of BaBi4Ti4O15 ceramics

    International Nuclear Information System (INIS)

    Chakrabarti, A.; Bera, J.

    2010-01-01

    Four-layer Aurivillius compound BaBi 4-x La x Ti 4 O 15 (x = 0.1-1.0) is synthesized by a modified chemical route. X-ray diffraction analysis confirms the formation of single-phase Aurivillius compound. The crystal structure of compound changes from orthorhombic to pseudo-tetragonal at x = 0.5. BaBi 4-x La x Ti 4 O 15 shows typical relaxor behaviour. With increasing La 3+ substitution, shift of T m towards lower temperature and increased relaxor behaviour is observed. The substitution also results in a marked improvement in the remnant polarization and coercive field. The Cole-Cole plots show the presence of two semicircular arcs, suggesting the existence of grain and grain-boundary effects. The dc-conductivity and activation energies for both grain and grain boundary are evaluated. The ceramics with x = 0.3 presents the lowest conductivity among all compositions.

  11. Optical Response of Cu1-xZnxIr2S4 Due to Metal--Insulator Transition

    International Nuclear Information System (INIS)

    Chen, L.; Matsunami, M.; Nanba, T.; Cao, G.; Suzuki, H.; Isobe, M.; Matsumoto, T.

    2003-01-01

    The mother material CuIr 2 S 4 of the thiospinel system Cu 1-x Zn x Ir 2 S 4 undergoes a temperature-induced metal--insulator (Mi) transition. We report the temperature dependence of the optical reflection spectra of Cu 1-x Zn x Ir 2 S 4 (x ≤ 0.5) at the temperatures of 8-300 K in the energy regions of 0.005--30 eV in order to study the change in the electronic structure due to the Zn substitution for Cu. Zn substitution induced mainly the splitting of the hybridization band between the Ir-5d(t 2g ) and S-3 p states crossing the E F . Obtained optical conductivity (σ ) spectrum is discussed in relation to the change in the electronic structure close to the E F . (author)

  12. Elastic fingering in rotating Hele-Shaw flows

    KAUST Repository

    Carvalho, Gabriel D.; Gadê lha, Hermes; Miranda, José A.

    2014-01-01

    The centrifugally driven viscous fingering problem arises when two immiscible fluids of different densities flow in a rotating Hele-Shaw cell. In this conventional setting an interplay between capillary and centrifugal forces makes the fluid-fluid interface unstable, leading to the formation of fingered structures that compete dynamically and reach different lengths. In this context, it is known that finger competition is very sensitive to changes in the viscosity contrast between the fluids. We study a variant of such a rotating flow problem where the fluids react and produce a gellike phase at their separating boundary. This interface is assumed to be elastic, presenting a curvature-dependent bending rigidity. A perturbative weakly nonlinear approach is used to investigate how the elastic nature of the interface affects finger competition events. Our results unveil a very different dynamic scenario, in which finger length variability is not regulated by the viscosity contrast, but rather determined by two controlling quantities: a characteristic radius and a rigidity fraction parameter. By properly tuning these quantities one can describe a whole range of finger competition behaviors even if the viscosity contrast is kept unchanged. © 2014 American Physical Society.

  13. Elastic fingering in rotating Hele-Shaw flows

    KAUST Repository

    Carvalho, Gabriel D.

    2014-05-21

    The centrifugally driven viscous fingering problem arises when two immiscible fluids of different densities flow in a rotating Hele-Shaw cell. In this conventional setting an interplay between capillary and centrifugal forces makes the fluid-fluid interface unstable, leading to the formation of fingered structures that compete dynamically and reach different lengths. In this context, it is known that finger competition is very sensitive to changes in the viscosity contrast between the fluids. We study a variant of such a rotating flow problem where the fluids react and produce a gellike phase at their separating boundary. This interface is assumed to be elastic, presenting a curvature-dependent bending rigidity. A perturbative weakly nonlinear approach is used to investigate how the elastic nature of the interface affects finger competition events. Our results unveil a very different dynamic scenario, in which finger length variability is not regulated by the viscosity contrast, but rather determined by two controlling quantities: a characteristic radius and a rigidity fraction parameter. By properly tuning these quantities one can describe a whole range of finger competition behaviors even if the viscosity contrast is kept unchanged. © 2014 American Physical Society.

  14. Treatment for GaSb surfaces using a sulphur blended (NH4)2S/(NH4)2SO4 solution

    International Nuclear Information System (INIS)

    Murape, D.M.; Eassa, N.; Neethling, J.H.; Betz, R.; Coetsee, E.; Swart, H.C.; Botha, J.R.; Venter, A.

    2012-01-01

    A sulphur based chemical, [(NH 4 ) 2 S/(NH 4 ) 2 SO 4 ] to which S has been added, not previously reported for the treatment of (1 0 0) n-GaSb surfaces, is introduced and benchmarked against the commonly used passivants Na 2 S·9H 2 O and (NH 4 ) 2 S. The surfaces of the treated material were studied by scanning electron microscopy (SEM), Auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS). It has been found that the native oxides present on the GaSb surface are more effectively removed when treated with ([(NH 4 ) 2 S/(NH 4 ) 2 SO 4 ] + S) than with (NH 4 ) 2 S or Na 2 S·9H 2 O, as evidenced by the ratio of the O 506eV to Sb 457eV AES peaks. XPS results reveal that Sb 2 S 3 /Sb 2 S 5 “replaces” Sb 2 O 3 /Sb 2 O 5 , suggesting that sulphur atoms substitute oxygen atoms in Sb 2 O 3 /Sb 2 O 5 to form Sb-S. It seems sulphurization only partially removes Ga 2 O 3 . Treatment with ([(NH 4 ) 2 S/(NH 4 ) 2 SO 4 ] + S) also results in a noteworthy improvement in the current-voltage (I-V) characteristics of Au/n-GaSb Schottky contacts compared to those fabricated on as-received material.

  15. Financial liberalization, currency substitution and savings in Nigeria: Evidence from cointegration and error correction modeling

    Directory of Open Access Journals (Sweden)

    M Aziakpono

    2004-04-01

    Full Text Available The study set out to test the McKinnon-Shaw proposition that financial liberalization will significantly increase savings mobilization. The results partly supported the financial liberalization proposition. Variables that capture the effects of currency substitution such as the interest rate differential, a proxy for underground economy, the inflation differential (as a measure of macroeconomic instability and a dummy for political instability were significant in their adverse impacts on the saving mobilization process in Nigeria. We, therefore, advocate for an active monetary policy that will help manage the delicate balance between domestic and foreign interest rates. This should be combined with macroeconomic policies that create a stable economic environment along with appropriate financial and exchange rate policies, in order to discourage economic agents from preferring foreign denominated assets to those held in the domestic currency.

  16. A single amino acid substitution in the S1 and S2 Spike protein domains determines the neutralization escape phenotype of SARS-CoV.

    Science.gov (United States)

    Mitsuki, Yu-ya; Ohnishi, Kazuo; Takagi, Hirotaka; Oshima, Masamichi; Yamamoto, Takuya; Mizukoshi, Fuminori; Terahara, Kazutaka; Kobayashi, Kazuo; Yamamoto, Naoki; Yamaoka, Shoji; Tsunetsugu-Yokota, Yasuko

    2008-07-01

    In response to SARS-CoV infection, neutralizing antibodies are generated against the Spike (S) protein. Determination of the active regions that allow viral escape from neutralization would enable the use of these antibodies for future passive immunotherapy. We immunized mice with UV-inactivated SARS-CoV to generate three anti-S monoclonal antibodies, and established several neutralization escape mutants with S protein. We identified several amino acid substitutions, including Y442F and V601G in the S1 domain and D757N and A834V in the S2 region. In the presence of each neutralizing antibody, double mutants with substitutions in both domains exhibited a greater growth advantage than those with only one substitution. Importantly, combining two monoclonal antibodies that target different epitopes effected almost complete suppression of wild type virus replication. Thus, for effective passive immunotherapy, it is important to use neutralizing antibodies that recognize both the S1 and S2 regions.

  17. Antimycobacterial and Photosynthetic Electron Transport Inhibiting Activity of Ring-Substituted 4-Arylamino-7-Chloroquinolinium Chlorides

    Directory of Open Access Journals (Sweden)

    Alois Cizek

    2013-09-01

    Full Text Available In this study, a series of twenty-five ring-substituted 4-arylamino-7-chloroquinolinium chlorides were prepared and characterized. The compounds were tested for their activity related to inhibition of photosynthetic electron transport (PET in spinach (Spinacia oleracea L. chloroplasts and also primary in vitro screening of the synthesized compounds was performed against mycobacterial species. 4-[(2-Bromophenylamino]-7-chloroquinolinium chloride showed high biological activity against M. marinum, M. kansasii, M. smegmatis and 7-chloro-4-[(2-methylphenylamino]quinolinium chloride demonstrated noteworthy biological activity against M. smegmatis and M. avium subsp. paratuberculosis. The most effective compounds demonstrated quite low toxicity (LD50 > 20 μmol/L against the human monocytic leukemia THP-1 cell line within preliminary in vitro cytotoxicity screening. The tested compounds were found to inhibit PET in photosystem II. The PET-inhibiting activity expressed by IC50 value of the most active compound 7-chloro-4-[(3-trifluoromethylphenylamino]quinolinium chloride was 27 μmol/L and PET-inhibiting activity of ortho-substituted compounds was significantly lower than this of meta- and para-substituted ones. The structure-activity relationships are discussed for all compounds.

  18. Enhanced electronic and magnetic properties by functionalization of monolayer GaS via substitutional doping and adsorption

    Science.gov (United States)

    Rahman, Altaf Ur; Rahman, Gul; Kratzer, Peter

    2018-05-01

    The structural, electronic, and magnetic properties of two-dimensional (2D) GaS are investigated using density functional theory (DFT). After confirming that the pristine 2D GaS is a non-magnetic, indirect band gap semiconductor, we consider N and F as substitutional dopants or adsorbed atoms. Except for N substituting for Ga (NGa), all considered cases are found to possess a magnetic moment. Fluorine, both in its atomic and molecular form, undergoes a highly exothermic reaction with GaS. Its site preference (FS or FGa) as substitutional dopant depends on Ga-rich or S-rich conditions. Both for FGa and F adsorption at the Ga site, a strong F–Ga bond is formed, resulting in broken bonds within the GaS monolayer. As a result, FGa induces p-type conductivity in GaS, whereas FS induces a dispersive, partly occupied impurity band about 0.5 e below the conduction band edge of GaS. Substitutional doping with N at both the S and the Ga site is exothermic when using N atoms, whereas only the more favourable site under the prevailing conditions can be accessed by the less reactive N2 molecules. While NGa induces a deep level occupied by one electron at 0.5 eV above the valence band, non-magnetic NS impurities in sufficiently high concentrations modify the band structure such that a direct transition between N-induced states becomes possible. This effect can be exploited to render monolayer GaS a direct-band gap semiconductor for optoelectronic applications. Moreover, functionalization by N or F adsorption on GaS leads to in-gap states with characteristic transition energies that can be used to tune light absorption and emission. These results suggest that GaS is a good candidate for design and construction of 2D optoelectronic and spintronics devices.

  19. Centrifugal fingering in a curved Hele-Shaw cell: A generalized Euler's elastica shape for the two-fluid interface

    Science.gov (United States)

    Miranda, Jose; Brandao, Rodolfo

    2017-11-01

    We study a family of generalized elastica-like equilibrium shapes that arise at the interface separating two fluids in a curved rotating Hele-Shaw cell. This family of stationary interface solutions consists of shapes that balance the competing capillary and centrifugal forces in such a curved flow environment. We investigate how the emerging interfacial patterns are impacted by changes in the geometric properties of the curved Hele-Shaw cell. A vortex-sheet formalism is used to calculate the two-fluid interface curvature, and a gallery of possible shapes is provided to highlight a number of peculiar morphological features. A linear perturbation theory is employed to show that the most prominent aspects of these complex stationary patterns can be fairly well reproduced by the interplay of just two interfacial modes. The connection of these dominant modes to the geometry of the curved cell, as well as to the fluid dynamic properties of the flow, is discussed. We thank CNPq (Brazilian Research Council) for financial support under Grant No. 304821/2015-2.

  20. Nanostructurization effects in PVP-stabilized tetra-arsenic tetra-sulfide As_4S_4 nanocomposites

    International Nuclear Information System (INIS)

    Shpotyuk, O.; Bujňáková, Z.; Baláž, P.; Ingram, A.; Demchenko, P.; Kovalskiy, A.; Vlcek, M.; Shpotyuk, Ya.; Cebulski, J.; Dziedzic, A.

    2017-01-01

    Nanostructurization in three types of tetra-arsenic tetra-sulfide As_4S_4 polymorphs composed by (1) preferential β-As_4S_4, (2) realgar α-As_4S_4 and (3) admixture of As_4S_4 in the form of β-realgar, pararealgar and intermediate χ-phase subjected to mechanochemical ball milling in a water solution of polyvinylpyrrolidone (PVP) are characterized with multiexperimental structure-sensitive probes. Void structure of pelletized As_4S_4-PVP nanocomposites is probed by positron annihilation lifetime spectroscopy complemented with atomic-sensitive techniques such as X-ray powder diffraction, Raman scattering and scanning electron microscopy with energy-dispersive X-ray spectroscopy. Appearance of arsenolite As_2O_3 crystallites is character for all As_4S_4 polymorphs affected by wet milling. Positron annihilation lifetime data considered in terms of substitution positron-positronium trapping confirm complicated nature of nanocomposites. Modified x3-x2-coupling decomposition algorithm developed in addition to unconstrained x3-term fitting procedure is applied to parameterize annihilation channels in these nanocomposites. Interfacial free-volume voids between neighboring nanoparticles in PVP environment are defined as most favorable trapping sites, they being rather loosely composed by As_4S_4 crystallites in full respect to variety of crystallographic polymorphs used for milling. Detected annihilation channels are ascribed preferentially to intrinsic free-volume voids insensitive to trapping states at the surface of oxidized nanocomposites. - Highlights: • PVP-stabilized tetra-arsenic tetra-sulfide nanocomposites prepared by wet milling. • As_4S_4-PVP composites by complementary atomic-specific and deficient structure probes. • Surface oxidation due to crystalline arsenolite As_2O_3 under wet milling. • Free-volume structure of PVP-stabilized As_4S_4 nanocomposites by PAL spectroscopy. • x3-x2-coupling decomposition algorithm to treat PAL data for As_4S_4

  1. ALK5 kinase inhibitory activity and synthesis of 2,3,4-substituted 5,5-dimethyl-5,6-dihydro-4H-pyrrolo[1,2-b]pyrazoles

    Czech Academy of Sciences Publication Activity Database

    Řezníčková, Eva; Tenora, L.; Pospíšilová, Pavlína; Galeta, J.; Jorda, Radek; Berka, K.; Majer, Pavel; Potáček, M.; Kryštof, Vladimír

    2017-01-01

    Roč. 127, FEB 15 (2017), s. 632-642 ISSN 0223-5234 R&D Projects: GA MŠk(CZ) LO1204; GA ČR(CZ) GA15-15264S; GA MŠk(CZ) LM2015047 Institutional support: RVO:61389030 ; RVO:61388963 Keywords : i-receptor kinase * beta signaling pathway * small- molecule inhibitor * tgf-beta * domain inhibitors * growth * fibrosis * cancer * potent * series * Transforming growth factor beta receptor I * Protein kinase * Inhibitor * Substituted pyrrolo[1,2-b]pyrazoles Subject RIV: FR - Pharmacology ; Medidal Chemistry OBOR OECD: Pharmacology and pharmacy; Pharmacology and pharmacy (UOCHB-X) Impact factor: 4.519, year: 2016

  2. F−/OH− substitution in [H4tren]4+ and [H3tren]3+ hydroxyfluorotitanates(IV) and classification of tren cation configurations

    International Nuclear Information System (INIS)

    Lhoste, Jérôme; Body, Monique; Legein, Christophe; Ribaud, Annie; Leblanc, Marc; Maisonneuve, Vincent

    2014-01-01

    Three [H 3 tren] 3+ or [H 4 tren] 4+ hydroxyfluorotitanates(IV) are solvothermally synthesized from TiO 2 , tren amine, 40% HF aqueous solution and ethanol under microwave heating at 120 °C and 190 °C. [H 4 tren]·(TiF 4.6 (OH) 1.4 ) 2 ·2.7H 2 O (I) and β-[H 3 tren]·(TiF 4.5 (OH) 1.5 )·(F) (II) are described for the first time. The third compound, α-[H 3 tren]·(TiF 4.7 (OH) 1.3 )·(F) (III), was previously reported as a pure fluorotitanate. The structure determinations are performed from single crystal (I) and powder (II) X-ray diffraction data. The F − /OH − substitution, expected from the presence of water in the reaction medium, is characterized by chemical analyses and 19 F MAS solid state NMR experiments: all three structures are built up from Ti(F,OH) 6 2− octahedra and “free” fluoride ions or water molecules. “Free” fluoride ions are not affected by F − /OH − substitution. The electroneutrality is ensured by triprotonated or tetraprotonated tren amines which adopt specific configurations. Additionally, based on the analysis of [H 3 tren] 3+ or [H 4 tren] 4+ hydroxo/oxo/fluorometalates, a classification of the configurations of tren cations is proposed. - Graphical abstract: The ratio of the relative intensities of the 19 F NMR lines assigned to F atoms belonging to isolated TiF 6−x (OH) x octahedra and to “free” fluoride ions shows that the F − /OH − substitution concerns only F atoms bonded to titanium. - Highlights: • Three tren templated hydroxyfluorotitanates(IV) have been solvothermally synthesized. • They are built up from Ti(F,OH) 6 2− octahedra and “free” F − ions or H 2 O molecules. • F − /OH − substitution does not affect “free” F − sites. • [H 4 tren] 4+ and [H 3 tren] 3+ cations adopt specific configurations. • A classification of the configurations of tren cations is proposed

  3. Polymorphisms A387P in thrombospondin-4 and N700S in thrombospondin-1 perturb calcium binding sites.

    Science.gov (United States)

    Stenina, Olga I; Ustinov, Valentin; Krukovets, Irene; Marinic, Tina; Topol, Eric J; Plow, Edward F

    2005-11-01

    Recent genetic studies have associated members of the thrombospondin (TSP) gene family with premature cardiovascular disease. The disease-associated polymorphisms lead to single amino acid changes in TSP-4 (A387P) and TSP-1 (N700S). These substitutions reside in adjacent domains of these highly homologous proteins. Secondary structural predictive programs and the homology of the domains harboring these amino acid substitutions to those in other proteins pointed to potential alterations of putative Ca2+ binding sites that reside in close proximity to the polymorphic amino acids. Since Ca2+ binding is critical for the structure and function of TSP family members, direct evidence for differences in Ca2+ binding by the polymorphic forms was sought. Using synthetic peptides and purified recombinant variant fragments bearing the amino acid substitutions, we measured differences in Tb3+ luminescence as an index of Ca2+ binding. The Tb3+ binding constants placed the TSP-1 region affected by N700S polymorphism among other high-affinity Ca2+ binding sites. The affinity of Ca2+ binding was lower for peptides (3.5-fold) and recombinant fragments (10-fold) containing the S700 vs. the N700 form. In TSP-4, the P387 form acquired an additional Ca2+ binding site absent in the A387 form. The results of our study suggest that both substitutions (A387P in TSP-4 and N700S in TSP-1) alter Ca2+ binding properties. Since these substitutions exert the opposite effects on Ca2+ binding, a decrease in TSP-1 and an increase in TSP-4, the two TSP variants are likely to influence cardiovascular functions in distinct but yet pathogenic ways.

  4. Wavelength selection in injection-driven Hele-Shaw flows: A maximum amplitude criterion

    Science.gov (United States)

    Dias, Eduardo; Miranda, Jose

    2013-11-01

    As in most interfacial flow problems, the standard theoretical procedure to establish wavelength selection in the viscous fingering instability is to maximize the linear growth rate. However, there are important discrepancies between previous theoretical predictions and existing experimental data. In this work we perform a linear stability analysis of the radial Hele-Shaw flow system that takes into account the combined action of viscous normal stresses and wetting effects. Most importantly, we introduce an alternative selection criterion for which the selected wavelength is determined by the maximum of the interfacial perturbation amplitude. The effectiveness of such a criterion is substantiated by the significantly improved agreement between theory and experiments. We thank CNPq (Brazilian Sponsor) for financial support.

  5. Single substitution in bacteriophage T4 RNase H alters the ratio between its exo- and endonuclease activities.

    Science.gov (United States)

    Kholod, Natalia; Sivogrivov, Dmitry; Latypov, Oleg; Mayorov, Sergey; Kuznitsyn, Rafail; Kajava, Andrey V; Shlyapnikov, Mikhail; Granovsky, Igor

    2015-11-01

    The article describes substitutions in bacteriophage T4 RNase H which provide so called das-effect. Phage T4 DNA arrest suppression (das) mutations have been described to be capable of partially suppressing the phage DNA arrest phenotype caused by a dysfunction in genes 46 and/or 47 (also known as Mre11/Rad50 complex). Genetic mapping of das13 (one of the das mutations) has shown it to be in the region of the rnh gene encoding RNase H. Here we report that Das13 mutant of RNase H has substitutions of valine 43 and leucine 242 with isoleucines. To investigate the influence of these mutations on RNase H nuclease properties we have designed a novel in vitro assay that allows us to separate and quantify exo- or endonuclease activities of flap endonuclease. The nuclease assay in vitro showed that V43I substitution increased the ratio between exonuclease/endonuclease activities of RNase H whereas L242I substitution did not affect the nuclease activity of RNase H in vitro. However, both mutations were necessary for the full das effect in vivo. Molecular modelling of the nuclease structure suggests that V43I substitution may lead to disposition of H4 helix, responsible for the interaction with the first base pairs of 5'end of branched DNA. These structural changes may affect unwinding of the first base pairs of gapped or nicked DNA generating a short flap and therefore may stabilize the DNA-enzyme complex. L242I substitution did not affect the structure of RNase H and its role in providing das-effect remains unclear. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. 4,4-Dimethyl- and diastereomeric 4-hydroxy-4-methyl-(2S)-glutamate analogues display distinct pharmacological profiles at ionotropic glutamate receptors and excitatory amino acid transporters

    DEFF Research Database (Denmark)

    Bunch, Lennart; Pickering, Darryl S; Gefflaut, Thierry

    2009-01-01

    this approach has provided important insight into the structure-activity relationships (SAR) for ionotropic and metabotropic glutamate receptors (iGluRs and mGluRs), as well as the excitatory amino acid transporters (EAATs). In this work, three 4,4-disubstituted Glu analogues 1-3, which are hybrid structures......Subtype-selective ligands are of great interest to the scientific community, as they provide a tool for investigating the function of one receptor or transporter subtype when functioning in its native environment. Several 4-substituted (S)-glutamate (Glu) analogues were synthesized, and altogether...

  7. Replacement of Oxygen by Sulfur in Small Organic Molecules. 3. Theoretical Studies on the Tautomeric Equilibria of the 2OH and 4OH-Substituted Oxazole and Thiazole and the 3OH and 4OH-Substituted Isoxazole and Isothiazole in the Isolated State and in Solution

    Directory of Open Access Journals (Sweden)

    Peter I. Nagy

    2016-07-01

    Full Text Available This follow-up paper completes the author’s investigations to explore the in-solution structural preferences and relative free energies of all OH-substituted oxazole, thiazole, isoxazole, and isothiazole systems. The polarizable continuum dielectric solvent method calculations in the integral-equation formalism (IEF-PCM were performed at the DFT/B97D/aug-cc-pv(q+(dz level for the stable neutral tautomers with geometries optimized in dichloromethane and aqueous solution. With the exception of the predictions for the predominant tautomers of the 3OH isoxazole and isothiazole, the results of the IEF-PCM calculations for identifying the most stable tautomer of the given species in the two selected solvents agreed with those from experimental investigations. The calculations predict that the hydroxy proton, with the exception for the 4OH isoxazole and 4OH isothiazole, moves preferentially to the ring nitrogen or to a ring carbon atom in parallel with the development of a C=O group. The remaining, low-fraction OH tautomers will not be observable in the equilibrium compositions. Relative solvation free energies obtained by the free energy perturbation method implemented in Monte Carlo simulations are in moderate accord with the IEF-PCM results, but consideration of the ΔGsolv/MC values in calculating ΔGstot maintains the tautomeric preferences. It was revealed from the Monte Carlo solution structure analyses that the S atom is not a hydrogen-bond acceptor in any OH-substituted thiazole or isothiazole, and the OH-substituted isoxazole and oxazole ring oxygens may act as a weak hydrogen-bond acceptor at most. The molecules form 1.0−3.4 solute−water hydrogen bonds in generally unexplored numbers at some specific solute sites. Nonetheless, hydrogen-bond formation is favorable with the NH, C=O and OH groups.

  8. High-energy lithium-ion battery using substituted LiCoPO4: From coin type to 1 Ah cell

    Science.gov (United States)

    Liu, D.; Zhu, W.; Kim, C.; Cho, M.; Guerfi, A.; Delp, S. A.; Allen, J. L.; Jow, T. R.; Zaghib, K.

    2018-06-01

    Cr, Fe and Si were added to improve the performance of olivine LiCoPO4 in cathodes for lithium-ion batteries. A substituted-LiCoPO4 in a half cell delivered a reversible capacity of 125 mAh/g at C/3 rate, with no capacity loss after over 100 cycles at 25 °C. The well-known capacity fade of LiCoPO4-based cathodes was almost completely eliminated by substituting Cr, Fe and Si.

  9. Innovation in hydroelectric power plant design in early twentieth century. Casto Fernández-Shaw's Engineering Architecture in La Jándula dam

    Directory of Open Access Journals (Sweden)

    A. B. Berrocal Menárguez

    2017-09-01

    Full Text Available The power plant location in the first hydroelectrial dams was a relevant issue at the end of XIX century and early XX. Different solutions were tried, some of them with very interesting aesthetics results and hydraulic and structural implications. Such is the case of La Jándula dam, inaugurated in 1930, that includes the power station inside the dam. This article examines the possible national and international inspirations of this singular solution, corroborating the hypothesis of its unprecedented nature. The collaboration of the architect Casto Fernández-Shaw in the design and integration of the engine room was decisive, because it achieved a result of an aesthetic quality and formal expressiveness unprecedented in a work of hydraulic engineering, as well as the birth of a style Shaw himself defined as architectural engineering.

  10. {μ-2-[4-(1,3-Benzothiazol-2-ylphenyl]-2-azapropane-1,3-dithiolato-κ4S,S′:S,S′}bis[tricarbonyliron(I

    Directory of Open Access Journals (Sweden)

    Da-yong Jiang

    2012-03-01

    Full Text Available The title compound, [Fe2(C15H12N2S3(CO6], was prepared as an azadithiolatodiiron model for the active site of [FeFe]-hydrogenase. The Fe2S2 core adopts a butterfly shape, with each metal having a pseudo square-pyramidal geometry. The N-substituted azadithiolate is μ2-κ4S,S′:S,S′-coordinated to the Fe(CO3 moieties to form two fused six-membered rings with different conformations. The sum of the C—N—C angles around the N atom [356.85 (15°] indicates a flattening of the trigonal–pyramidal geometry about the N atom and an increase in the degree of sp2-hybridization.

  11. Solvent-free one-pot cyclization and acetylation of chalcones: Synthesis of some 1-acetyl pyrazoles and spectral correlations of 1-(3-(3,4-dimethylphenyl-5-(substituted phenyl-4,5-dihydro-1H-pyrazole-1-yl ethanones

    Directory of Open Access Journals (Sweden)

    G. Thirunarayanan

    2016-11-01

    Full Text Available One-pot synthesis of some 1N-acetyl pyrazoles including 1-(3-(3,4-dimethylphenyl-5-(substituted phenyl-4,5-dihydro-1H-pyrazole-1-yl ethanones has been achieved via solvent-free microwave irradiation using substituted chalcones, hydrazine hydrate and acetic anhydride in the presence of catalytic amount of fly-ash: PTS catalyst. The yield of these 1N-acetyl pyrazole derivatives is more than 75%. The synthesized 1N-acetyl pyrazoline derivatives were characterized by their physical constants and spectral data. The infrared spectral νCN and CO (cm−1 frequencies, NMR chemical shifts (δ, ppm of Ha, Hb, Hc, CH3 protons, CN, CO and CH3 carbons of 1-(3-(3,4-dimethylphenyl-5-(substituted phenyl-4,5-dihydro-1H-pyrazole-1-yl ethanones have been assigned and correlated with Hammett substituent constants and Swain-Lupton’s parameters using single and multi-regression analysis. From the results of statistical analyses, the effect of substituents on the above group frequencies and chemical shifts of the acetylated pyrazoles were discussed.

  12. SELECTIVE C-2 AND C-4 DEACYLATION AND ACYLATION OF TAXOL - THE FIRST SYNTHESIS OF A C-4 SUBSTITUTED TAXOL ANALOG

    DEFF Research Database (Denmark)

    GEORG, GI; ALI, SM; BOGE, TC

    1994-01-01

    Hydrolytic procedures for selective 2-debenzoylation and 2,4-dideacylation of 2'-0-tert-butyldimethylsilyl-7-0-(triethylsilyl)taxol are reported. The first synthesis and biological evaluation of a 4-substituted analogue, 4-deacetyl-4-isobutanoyltaxol, is presented. The chemistry described in this...... in this letter is suitable for the facile synthesis of taxol congeners modified at C-2 and/or C-4....

  13. A study of gas bubbles in liquid mercury in a vertical Hele-Shaw cell

    Energy Technology Data Exchange (ETDEWEB)

    Klaasen, B.; Blanpain, B. [KU Leuven, Research Group for High Temperature Processes and Industrial Ecology, Department of Metallurgy and Materials Engineering, Leuven (Belgium); Verhaeghe, F. [KU Leuven, Research Group for High Temperature Processes and Industrial Ecology, Department of Metallurgy and Materials Engineering, Leuven (Belgium); Umicore Group Research and Development, Olen (Belgium); Fransaer, J. [KU Leuven, Research Group for Materials with Novel Functionality, Department of Metallurgy and Materials Engineering, Leuven (Belgium)

    2014-01-15

    High-quality observations of mesoscopic gas bubbles in liquid metal are vital for a further development of pyrometallurgical gas injection reactors. However, the opacity of metals enforces the use of indirect imaging techniques with limited temporal or spatial resolution. In addition, accurate interface tracking requires tomography which further complicates the design of a high-temperature experimental setup. In this paper, an alternative approach is suggested that circumvents these two main restrictions. By injecting gas in a thin layer of liquid metal entrapped between two flat and closely spaced plates, bubbles in a Hele-Shaw flow regime are generated. The resulting quasi-2D multiphase flow phenomena can be fully captured from a single point of view and, when using a non-wetted transparent plate material, the bubbles can be observed directly. The feasibility of this approach is demonstrated by observations on buoyancy-driven nitrogen bubbles in liquid mercury in a vertical Hele-Shaw cell. By using a moving high-speed camera to make continuous close up recordings of individual bubbles, the position and geometry of these bubbles are quantified with a high resolution along their entire path. After a thorough evaluation of the experimental accuracy, this information is used for a detailed analysis of the bubble expansion along the path. While the observed bubble growth is mainly caused by the hydrostatic pressure gradient, a careful assessment of the volume variations for smaller bubbles shows that an accurate bubble description should account for significant dynamic pressure variations that seem to be largely regime dependent. (orig.)

  14. 40 CFR 721.10048 - Substituted anthraquinone (generic).

    Science.gov (United States)

    2010-07-01

    ..., and consumer activities. Requirements as specified in § 721.80(s) (4,500 kilograms). (ii) [Reserved... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Substituted anthraquinone (generic). 721.10048 Section 721.10048 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED...

  15. Effect of VO43− substitution for PO43− on electrochemical properties of the Li3Fe2(PO4)3 cathode materials

    International Nuclear Information System (INIS)

    Yang, Yonggang; Zhang, Yongguang; Hua, Zhengshen; Wang, Xin; Peng, Huifen; Bakenov, Zhumabay

    2016-01-01

    Graphical abstract: VO 4 3− –substituted Li 3 Fe 2 (PO 4 ) 3 samples were prepared by sol-gel method. The VO 4 3− substitution remarkably improves the rate capability and cycling performance of the Li 3 Fe 2 (PO 4 ) 3 due to improved conductivity and enhanced lithium ion diffusion. - Highlights: • Mixed anion effect was used to improve electrochemical properties of Li 3 Fe 2 (PO 4 ) 3 . • The VO 4 3− substitution improved rate capability and cyclability of Li 3 Fe 2 (PO 4 ) 3 . • The Li 3 Fe 2 (PO 4 ) 2.55 (VO 4 ) 0.45 material shows the excellent electrochemical performance. - Abstract: In this research, VO 4 3− substitution was used to improve electrochemical properties of the Nasicon Li 3 Fe 2 (PO 4 ) 3 cathode material. The VO 4 3− substitution resulted in formation of a homogeneous compound Li 3 Fe 2 (PO 4 ) 3-x (VO 4 ) x in a composition range of x ≤ 0.45; further introduction of VO 4 3− led to precipitation of some other phases. It was shown that the VO 4 3− substituted samples presented discharging capacity higher than that of bare non-substituted Nasicon and the reported Ti 4+ and Mn 2+ doped ones. The Li 3 Fe 2 (PO 4 ) 2.55 (VO 4 ) 0.45 material exhibited excellent cycling stability and rate capability, and retained a capacity of 91.8 mAh g −1 after 60 cycles at 2C charge-discharge rate. This value is one of the highest reported to date for the Li 3 Fe 2 (PO 4 ) 3 compound, and was about 48% higher than that of the latter. The electrochemical performance enhancements for the VO 4 3− substituted samples were attributed to the reduction of charge transfer resistance, increase of electrical conductivity, and fast lithium ion diffusion behavior. Hence, the obtained results proved that the VO 4 3− anion substitution for PO 4 3− is a powerful technique to improve the electrochemical performance of the studied Nasicon compound.

  16. Synthesis, antimicrobial, and anti-inflammatory activities of novel 2-[3-(1-adamantyl)-4-substituted-5-thioxo-1,2,4-triazolin-1-yl] acetic acids, 2-[3-(1-adamantyl)-4-substituted-5-thioxo-1,2,4-triazolin-1-yl]propionic acids and related derivatives.

    Science.gov (United States)

    Al-Deeb, Omar A; Al-Omar, Mohamed A; El-Brollosy, Nasser R; Habib, Elsayed E; Ibrahim, Tarek M; El-Emam, Ali A

    2006-01-01

    The reaction of 3-(1-adamantyl)-4-substituted-1,2,4-triazoline-5-thiones 3a-g with sodium chloroacetate, in ethanolic sodium hydroxide yielded the corresponding N1-acetic acid derivatives 4a-g. The interaction of 3a-g with ethyl 2-bromopropionate in acetone, in the presence of potassium carbonate, yielded the corresponding N1-ethyl propionate derivatives 5a-g, which upon hydrolysis with aqueous sodium hydroxide afforded the corresponding propionic acid derivatives 6a-g. Similarly, the reaction of 3-(1-adamantyl)-4-amino-1,2,4-triazoline-5-thione 7 with sodium chloroacetate in ethanolic sodium hydroxide yielded the corresponding N1-acetic acid derivative 8. On the other hand, the reaction of 2-(1-adamantyl)-1,3,4-oxadiazoline-5-thione 9 with sodium chloroacetate yielded the corresponding S-acetic acid derivative 10. Compounds 4a-g, 5b, 5c, 5g, 6a-g, 8 and 10 were tested for in vitro activities against a panel of Gram-positive and Gram-negative bacteria and the yeast-like pathogenic fungus Candida albicans. Several derivatives produced good or moderate activities particularly against Bacillus subtilis. In addition, the in vivo anti-inflammatory activities of these compounds were determined using the carrageenin-induced paw oedema method in rats. Compounds 4a, 4b, 4e, 4f, 6f, 6g and 10 produced good dose-dependent anti-inflammatory activities.

  17. The S230R Integrase Substitution Associated with Viral Rebound during DTG Monotherapy Confers Low Levels INSTI Drug Resistance.

    Science.gov (United States)

    Pham, Hanh T; Labrie, Lydia; Wijting, Ingeborg E A; Hassounah, Said; Lok, Ka Yee; Portna, Inna; Goring, Mark; Han, Yingshan; Lungu, Cynthia; van der Ende, Marchina E; Brenner, Bluma G; Boucher, Charles A; Rijnders, Bart J A; van Kampen, Jeroen J A; Mesplède, Thibault; Wainberg, Mark A

    2018-03-29

    Dolutegravir (DTG) is an integrase strand-transfer inhibitor (INSTI) used for treatment of HIV-infected individuals. Due to its high genetic barrier to resistance, DTG has been clinically investigated as maintenance monotherapy to maintain viral suppression and to reduce complication and healthcare costs. Our study aims to explain the underlying mechanism related to the emergence of a S230R substitution in patients who experienced virological failure while using DTG monotherapy. We evaluated the effect of S230R substitution in regard to IN enzyme activity, viral infectivity, replicative capacity and susceptibility to different INSTIs by biochemical and cell-based assays. S230R substitution conferred 63% reduction in enzyme efficiency. The S230R virus was 1.29-fold less infectious than wildtype (WT), but could replicate in PM1 cells without significant delay. Resistance levels against DTG, CAB, RAL and EVG in tissue culture were 3.85-, 3.72-, 1.52-, and 1.21-fold, respectively. Our data indicate that the S230R substitution is comparable to the previously reported R263K in some respects. Virological failure under DTG monotherapy can occur through the development of such S230R or R263K mutations without the need for high levels DTG resistance.

  18. Bubble propagation in Hele-Shaw channels with centred constrictions

    Science.gov (United States)

    Franco-Gómez, Andrés; Thompson, Alice B.; Hazel, Andrew L.; Juel, Anne

    2018-04-01

    We study the propagation of finite bubbles in a Hele-Shaw channel, where a centred occlusion (termed a rail) is introduced to provide a small axially uniform depth constriction. For bubbles wide enough to span the channel, the system’s behaviour is similar to that of semi-infinite fingers and a symmetric static solution is stable. Here, we focus on smaller bubbles, in which case the symmetric static solution is unstable and the static bubble is displaced towards one of the deeper regions of the channel on either side of the rail. Using a combination of experiments and numerical simulations of a depth-averaged model, we show that a bubble propagating axially due to a small imposed flow rate can be stabilised in a steady symmetric mode centred on the rail through a subtle interaction between stabilising viscous forces and destabilising surface tension forces. However, for sufficiently large capillary numbers Ca, the ratio of viscous to surface tension forces, viscous forces in turn become destabilising thus returning the bubble to an off-centred propagation regime. With decreasing bubble size, the range of Ca for which steady centred propagation is stable decreases, and eventually vanishes through the coalescence of two supercritical pitchfork bifurcations. The depth-averaged model is found to accurately predict all the steady modes of propagation observed experimentally, and provides a comprehensive picture of the underlying steady bifurcation structure. However, for sufficiently large imposed flow rates, we find that initially centred bubbles do not converge onto a steady mode of propagation. Instead they transiently explore weakly unstable steady modes, an evolution which results in their break-up and eventual settling into a steady propagating state of changed topology.

  19. Ab initio understanding of magnetic properties in Zn2+ substitution of Fe3O4 ultra-thin film with dilute Zn substitution

    Science.gov (United States)

    Huang, Zhaocong; Chen, Qian; Jiang, Sheng; Dong, Shuai; Zhai, Ya

    2018-05-01

    The mechanism of the magnetic properties on the Zn2+ substituted Fe3O4 film have been investigated based on first principle calculations. It is found that the surface effect plays an important role in the occupation of Zn ion, and in turn changes the magnetic moment. It may also destroy the half metallic behavior of Fe3O4 film even if the Zn2+ concentration only is one Zn2+ per unit cell (4%), which is different from that in bulk material.

  20. Structural, morphological and dielectric studies of zirconium substituted CoFe2O4 nanoparticles

    Directory of Open Access Journals (Sweden)

    S. Anand

    2017-12-01

    Full Text Available In this work, the influence of zirconium substitution in cubic spinel nanocrystalline CoFe2O4 on the structural, morphological and dielectric properties are reported. Zirconium substituted cobalt ferrite Co1-xZrxFe2O4 (x = 0.7 nanoparticles were synthesized by sol-gel route. The structural and morphological investigations using powder X-ray diffraction and high resolution scanning electron microscope (HRSEM analysis are reported. Scherrer plot, Williamson–Hall analysis and Size-strain plot method were used to calculate the crystallite size and lattice strain of the samples. High purity chemical composition of the sample was confirmed by energy dispersive X-ray analysis. The atoms vibration modes of as synthesized nanoparticles were recorded using Fourier transform infrared (FTIR spectrometer in the range of 4000–400 cm-1. The temperature-dependent dielectric properties of zirconium substituted cobalt ferrite nanoparticles were also carried out. Relative dielectric permittivity, loss tangent and AC conductivity were measured in the frequency range 50 Hz to 5 MHz at temperatures between 323 K and 473 K. The dielectric constant and dielectric loss values of the sample decreased with increasing in the frequency of the applied signal.

  1. Microstructure and Electrical Properties of Fe,Cu Substituted (Co,Mn)3O4 Thin Films

    DEFF Research Database (Denmark)

    Szymczewska, Dagmara; Molin, Sebastian; Hendriksen, Peter Vang

    2017-01-01

    In this work, thin films (~1000 nm) of a pure MnCo2O4 spinel together with its partially substituted derivatives (MnCo1.6Cu0.2Fe0.2O4, MnCo1.6Cu0.4O4, MnCo1.6Fe0.4O4) were prepared by spray pyrolysis and were evaluated for electrical conductivity. Doping by Cu increases the electrical conductivit...

  2. Preparation and Properties of Isomeric N-(4-substituted Benzylidene)-4-ethynylanilines and 4-substituted N-(4-ethynylbenzylidene) Anilines

    Czech Academy of Sciences Publication Activity Database

    Balcar, Hynek; Čejka, Jiří; Kubišta, Jiří; Petrusová, Lidmila; Kubát, Pavel; Blechta, Vratislav

    2000-01-01

    Roč. 65, č. 2 (2000), s. 203-215 ISSN 0010-0765 R&D Projects: GA ČR GA203/98/1165 Institutional research plan: CEZ:AV0Z4040901; CEZ:A54/98:Z4-040-9-ii Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 0.960, year: 2000

  3. A-site substitution effect of strontium on bismuth layered CaBi4Ti4O15 ceramics on electrical and piezoelectric properties

    International Nuclear Information System (INIS)

    Tanwar, Amit; Verma, Maya; Gupta, Vinay; Sreenivas, K.

    2011-01-01

    Strontium substituted CaBi 4 Ti 4 O 15 ceramics with the chemical formula Ca 1-x Sr x Bi 4 Ti 4 O 15 (CSBT) (x = 0.0-1.0) have been prepared through conventional solid state route. The formation of single phase material with orthorhombic structure was verified from X-ray diffraction with incorporation of Sr substitution. Decrease in a-axis displacement of Bi ion in the perovskite structure in the CSBT ceramics were observed from the relative changes in soft mode (20 cm -1 ) in the Raman spectra, and increase in Sr incorporation shows the shift in ferroelectric to paraelectric phase transition temperature. The dielectric properties for all the CSBT ceramic compositions are studied as a function of temperature over the frequency range of 100 Hz-1 MHz. Curie's temperature was found to be function of Sr substitution and with increase in the Sr concentration the phase transition becomes sharper and phase transition temperature gets shifted towards lower temperature (790-545 deg. C). The behavior of ac conductivity as a function of frequency (100 Hz-1 MHz) at low temperature ( 33 ) whereas piezoelectric charge coefficient values were found comparable to that of PZT at room temperature. Relative changes in soft modes due to Sr incorporation results in high piezoelectricity in the CSBT ceramics.

  4. 40 CFR 721.10152 - Oxirane, substituted silylmethyl-, hydrolysis products with alkanol zirconium(4+) salt and silica...

    Science.gov (United States)

    2010-07-01

    ...-, hydrolysis products with alkanol zirconium(4+) salt and silica, acetates (generic). 721.10152 Section 721... Oxirane, substituted silylmethyl-, hydrolysis products with alkanol zirconium(4+) salt and silica... zirconium(4+) salt and silica, acetates (PMN P-07-674) is subject to reporting under this section for the...

  5. Femtosecond transient photoluminescence of the substituted poly(diphenylacetulene)s.

    Science.gov (United States)

    Piskun, N. V.; Wang, D. K.; Lim, H.; Epstein, A. J.; Vanwoerkom, L. D.; Gustafson, T. L.

    2000-03-01

    We present the results of a femtosecond transient photoluminescence (PL) study of solutions of two derivatives of substituted poly(diphenylacetylene) using an up-conversion technique. n-Butyl (nBu) and p-carbazole (Cz) substituted poly(diphenylacetylene), PDPA-nBu and PDPA-Cz respectively, have band gaps determined by maxima in the slope of absorption vs. energy of 2.75 eV and 2.63 eV. The steady state emission peaks are at 2.4 eV for PDPA-nBu and at 2.3 eV for PDPA-Cz respectively. The PL peak for PDPA-Cz is red shifted in comparison to the PL peak for PDPA-nBu. Roles of phenyl groups, electron donating effect of the carbazole side units and planarity of the backbone are discussed. Exciting at 3.1 eV, the fs PL shows a faster decay for PDPA-Cz than that for PDPA-nBu, in accord with the decrease of PL quantum efficiency of PDPA-Cz. The 200 fs - 80 ps PL(t) agrees with ~1 ns lifetime. The PDPA-Cz has larger red shift in the 0.2-20 ps time frame. The origin of that shift will be discussed. This work is supported in part by ONR.

  6. Structural and light up-conversion luminescence properties of Er3+-Yb3+-W6+ substituted Bi4Ti3O12

    Science.gov (United States)

    Bokolia, Renuka; Rai, Vineet K.; Chauhan, Lalita; Sreenivas, K.

    2016-05-01

    The structural and light up-conversion (UC) luminescence properties of W6+ substituted Bi3.79Er0.03Yb0.18Ti3-xWxO12 (0 ≤ x ≤ 0.10) ceramics prepared by solid state reaction method have been investigated. X-ray diffraction (XRD) confirms the formation of single phase material with orthorhombic structure. A decrease in the lattice parameters and unit cell volume is observed with increasing W content. Strong UC luminescence at 527, 548 and 662 nm is seen under an excitation of 980 nm for an optimum W content (x = 0.06) and is attributed to the transitions 2H11/2 →4I15/2, 4S3/2 →4I15/2 and 4F9/2 →4I15/2 respectively. The improved UC luminescence is ascribed to the reduced defects such as oxygen vacancies and change in the crystal field around Er3+ ions due to B-site (Ti4+) substitution with W6+ ions. Enhanced UC emission is observed for an optimum content of w6+ in the prepared composition Bi3.79Er0.03Yb0.18Ti3-xWxO12 for x = 0.06.

  7. Synthesis of (E)-N'-[1-(2,4-Dihydroxyphenyl)ethylidene]substituted hydrazides as possible alpha-glucosidase and butyrylcholinesterase Inhibitors

    International Nuclear Information System (INIS)

    Abbasi, M.A.; Shah, S.A.H.; Siddiqui, S.Z.; Khan, K.M.

    2017-01-01

    In the current research work, (E)-N'-[1-(2,4-dihydroxyphenyl)ethylidene]substituted hydrazides were synthesized in a couple of steps and their enzyme inhibition potential was analyzed. Firstly 2,4-hydroxyacetophenone (1) was reacted with hydrated hydrazine (2) under stirring to yield (E)-4-(1-hydrazonoethyl)benzene-1,3-diol (3) which was further reacted with different acid halides, (4a-i) to afford (E)-[1-(2,4-dihydroxyphenyl)ethylidene]substituted hydrazides (5a-i). These synthesized compounds were characterized by EI-MS, 1H-NMR spectral techniques and were also evaluated against a-glucosidase and butyrylcholinesterase enzymes. The synthesized compounds were found to be acceptable inhibitors of a-glucosidase and decent inhibition against butyrylcholinesterase. (author)

  8. Silica-Supported Polyphosphoric Acid in the Synthesis of 4-Substituted Tetrahydroisoquinoline Derivatives

    Directory of Open Access Journals (Sweden)

    Iliyan Ivanov

    2013-02-01

    Full Text Available We report herein an application of an α-amidoalkylation reaction, as an alternative efficient synthesis of 4-aryl- and 4-methyl-1,2,3,4-tetrahydroisoquinoline derivatives. The amides required for this purpose would result from reaction of aminoacetaldehyde dimethylacetal with different substituted benzenes in polyphosphoric acid, followed by acylation of the obtained amines with different acid chlorides or sulfochlorides. We compared the cyclisation step using conventional (milieu of acetic-trifluoracetic acid = 4:1 and solid supported reagents (SiO2/PPA, as recovered, regenerated and reused without loss of its activity catalyst. We found that in comparison to conventional methods, the yields of the reaction are greater and the reaction time is shorter.

  9. Two-dimensional magnetism in the triangular antiferromagnet NiGa2S4

    International Nuclear Information System (INIS)

    Nambu, Yusuke

    2013-01-01

    At sufficiently low temperatures, electron spins in normal magnets generally order into some fashion, for instance, ferromagnetic and antiferromagnetic. Geometrical frustration and/or reduced dimensionality can suppress such conventional orders, and occasionally induce unknown states of matter. This is the case for the two-dimensional (2D) triangular antiferromagnet Ni(Ga 2 S 4 , in which S=1 nickel spins do not order, instead show an exotic magnetism. We found (1) a resonant critical slowing down toward T*=8.5 K followed by a viscous spin liquid behavior, and (2) a spin-size dependent ground state. To elucidate (1), spin dynamics ranging from 10 -13 to 10 0 seconds were quantitatively explored through the experimental techniques such as inelastic neutron scattering, backscattering, neutron spin echo, ac and nonlinear susceptibilities. The finding of (2) is evidenced by impurity effects. Integer spins substituted systems such as zinc and iron ions retain a quadratic temperature dependence of the magnetic specific heat as for the parent compound. However, substitutions of half-odd integer spins, cobalt and manganese ions, eventually induce a distinct behavior, indicating an importance of integer size of spins to stabilize the 2D magnetism realized in NiGa 2 S 4 . The article gives our experimental findings and as well as some relevant theoretical scenarios. (author)

  10. Natural convection heat transfer in an anisotropic porous cavity heated from the side. 2nd Report. experiment by hele-shaw cell; Tosuiritsu ni ihosei wo yusuru howa takoshitsu sonai no sokuho kanetsu ni yoru shizen tairyu netsu dentatsu. 2. Hele shaw cell ni yoru jikken

    Energy Technology Data Exchange (ETDEWEB)

    Kimura, S; Okajima, A; Kiwata, T [Kanazawa University, Ishikawa (Japan). Faculty of Engineering

    2000-11-25

    Natural convection heat transfer and flow structure in an anisotropic porous medium of square cavity saturated with Boussinesq fluid has been studied experimentally using a Hele-Shaw cell. The permeability ratio defined by K=K{sub y}/K{sub x} was put to three different values; 0.4, 1 and 2.5. The convection patterns at three different permeability ratios are visualized for several different Rayleigh numbers by the pH indicator method. When K is 0.25, the visualized flow is mainly in the vertical direction. On the contrary for K=4 the convecting flow is in the horizontal direction. The average heat transfer coefficients are also measured, and the corresponding Nusselt number are plotted as a function of K. It is found that the corresponding Nusselt numbers are scaled with (KRa){sup 1/2}. The experimental results of flow pattern and heat transfer are accord with those obtained by our previous theory. (author)

  11. Acid catalyzed solvent free synthesis of new 1-acyl-4-benzhydryl substituted pyrazoles

    International Nuclear Information System (INIS)

    Sher, M.; Kausar, T.; Riaz, N.; Sharif, A.

    2016-01-01

    A convenient, cost effective and environmentally benign methodology has been developed, which delivered fourteen new 1-acyl-4-benzhyrdyl substituted pyrazole derivatives under solvent free conditions. Target compounds were synthesized in good to excellent yields simply by grinding reactants in a pestle and mortar with catalytic amount of conc. H/sub 2/SO/sub 4/. All the newly formed compounds were fully characterized with the help of detailed spectroscopic techniques including FTIR, NMR and GC-MS. (author)

  12. Reactivity and Regioselectivity in the Heck Reaction - A Hammett Study of 4-Substituted Styrenes

    DEFF Research Database (Denmark)

    Fristrup, Peter; Le Quement, Sebastian; Tanner, David Ackland

    2004-01-01

    The regioselectivity in the cationic Heck reaction of 4-substituted styrenes was addressed by a Hammett study. In this branching reaction, plots based on the substrate reactivity did not give meaningful data, whereas the product distribution was variable due to differing preferences for further...

  13. 4-N, N-bis(4-methoxylphenyl) aniline substituted anthraquinone: X-ray crystal structures, theoretical calculations and third-order nonlinear optical properties

    Science.gov (United States)

    Xu, Liang; Zhang, Dingfeng; Zhou, Yecheng; Zheng, Yusen; Cao, Liu; Jiang, Xiao-Fang; Lu, Fushen

    2017-08-01

    In this paper, mono- and di-4-N,N-bis(4-methoxylphenyl)aniline-substituted anthraquinone have been designed and synthesized through Suzuki reaction. For mono-4-N,N-bis(4-methoxylphenyl)aniline-substituted anthraquinone, polymorphous crystal structures have been obtained in different crystallization conditions. Electrochemical characterization combined with theoretical calculation suggests that the addition of a second triphenylamine unit causes a larger band gap with higher lying LUMO (Lowest Unoccupied Molecular Orbital) and HOMO (Highest Occupied Molecular Orbital). The linear optical property shows that the introduction of a second triphenylamine unit bring about a significant hyperchromic effect with the extinction coefficients increasing from 11199 M-1 cm-1 to 22136 M-1 cm-1. The third-order nonlinear optical properties indicate that the introduction of a second triphenylamine unit lead to a much larger nonlinear absorption coefficient and two-photon absorption cross section, with the relevant value increasing from 2.04 × 10-12 cm W-1 to 3.91 × 10-12 cm W-1, and from 148 GM to 286 GM, respectively.

  14. Synthesis, enzyme inhibitory kinetics mechanism and computational study of N-(4-methoxyphenethyl-N-(substituted-4-methylbenzenesulfonamides as novel therapeutic agents for Alzheimer’s disease

    Directory of Open Access Journals (Sweden)

    Muhammad Athar Abbasi

    2018-06-01

    Full Text Available The present study comprises the synthesis of a new series of sulfonamides derived from 4-methoxyphenethylamine (1. The synthesis was initiated by the reaction of 1 with 4-methylbenzenesulfonyl chloride (2 in aqueous sodium carbonate solution at pH 9 to yield N-(4-methoxyphenethyl-4-methylbenzensulfonamide (3.This parent molecule 3 was subsequently treated with various alkyl/aralkyl halides, (4a–j, using N,N-dimethylformamide (DMF as solvent and LiH as activator to produce a series of new N-(4-methoxyphenethyl-N-(substituted-4-methylbenzenesulfonamides (5a–j. The structural characterization of these derivatives was carried out by spectroscopic techniques like IR, 1H-NMR, and 13C-NMR. The elemental analysis data was also coherent with spectral data of these molecules. The inhibitory effects on acetylcholinesterase and DPPH were evaluated and it was observed that N-(4-Methoxyphenethyl-4-methyl-N-(2-propylbenzensulfonamide (5c showed acetylcholinesterase inhibitory activity 0.075 ± 0.001 (IC50 0.075 ± 0.001 µM comparable to Neostigmine methylsulfate (IC50 2.038 ± 0.039 µM.The docking studies of synthesized ligands 5a–j were also carried out against acetylcholinesterase (PDBID 4PQE to compare the binding affinities with IC50 values. The kinetic mechanism analyzed by Lineweaver-Burk plots demonstrated that compound (5c inhibits the acetylcholinesterase competitively to form an enzyme inhibitor complex. The inhibition constants Ki calculated from Dixon plots for compound (5c is 2.5 µM. It was also found from kinetic analysis that derivative 5c irreversible enzyme inhibitor complex. It is proposed on the basis of our investigation that title compound 5c may serve as lead structure for the design of more potent acetylcholinesterase inhibitors.

  15. Stereocomplementary Construction of Optically Active Bicyclo[4.3.0]nonenone Derivatives.

    Science.gov (United States)

    Mukai, Chisato; Kim, Jin Sung; Sonobe, Hiroshi; Hanaoka, Miyoji

    1999-09-03

    Treatment of (5S,6S)-5,6-bis(tert-butyldimethylsiloxy)-8-(substituted)oct-1-en-7-yne derivatives, prepared from diethyl L-tartrate, with Co(2)(CO)(8) afforded the corresponding cobalt-complexed enynes, which were subsequently exposed to the typical Pauson-Khand conditions to furnish highly stereoselectively or exclusively (2S,3S,6S)-2,3-bis(tert-butyldimethylsiloxy)-9-(substituted)bicyclo[4.3.0]non-1(9)-en-8-ones. On the other hand, (3S,4S)-1-(substituted)oct-7-en-1-yne-3,4-diol congeners produced, on exposure to the Pauson-Khand conditions, (2S,3S,6R)-2,3-dihydroxy-9-(substituted)bicyclo[4.3.0]-non-1(9)-en-8-one derivatives in a highly stereoselective manner. The newly developed procedure has been shown to be useful for construction of the 2,3-bis(oxygenated)-7-(substituted)bicyclo[4.3.0]non-6-en-8-one framework in a stereocomplementary as well as stereoselective fashion.

  16. Billy Shaw Dam and Reservoir: Environmental assessment and finding of no significant impacts

    International Nuclear Information System (INIS)

    1997-03-01

    This notice announces BPA's decision to fund the construction, operation, and maintenance of the Billy Shaw Dam and Reservoir on the Duck Valley Reservation. This project is part of a continuing effort to address system-wide fish and wildlife losses caused by the development of the hydropower system in the Columbia River Basin. BPA has prepared an Environmental Assessment (EA) evaluating the potential environmental impacts of the proposed project. Based on the analysis in the EA, BPA has determined that the Proposed Action is not a major Federal action significantly affecting the quality of the human environment, within the meaning of the National Environmental Policy Act (NEPA) of 1969. Therefore, the preparation of an Environmental Impact Statement (EIS) is not required and BPA is issuing this FONSI

  17. 4D-π-1A type β-substituted ZnII-porphyrins: ideal green sensitizers for building-integrated photovoltaics.

    Science.gov (United States)

    Covezzi, A; Orbelli Biroli, A; Tessore, F; Forni, A; Marinotto, D; Biagini, P; Di Carlo, G; Pizzotti, M

    2016-10-18

    Two novel green β-substituted Zn II -porphyrins, G1 and G2, based on a 4D-π-1A type substitution pattern have been synthesized. Their enhanced push-pull character, by reduction of H-L energy gaps, promotes broadening and red-shifting of absorption bands. The effective synthetic pathway and the remarkable spectroscopic properties make G2 ideal for BIPV application.

  18. Novel 5-Fluorouracil Derivatives: Synthesis and Cytotoxic Activity of 2-Butoxy-4-Substituted 5-Fluoropyrimidines

    International Nuclear Information System (INIS)

    Sun, Jian; Zhou, Wei; Hu, Weixiao; Shan, Shang; Zhang, Shijie; Li, Haibo

    2013-01-01

    Twenty two new 5-fluorouracil (5-FU) derivatives, 2-butoxy-4-substituted 5-fluoropyrimidines, were synthesized and characterized by IR, 1 H NMR, MS, HRMS. All compounds were preliminarily evaluated by MTT assay on human liver BEL-7402 cancer cell line in vitro. Ten compounds were selected to test their cytotoxic activity against A549, HL-60 and MCF-7 cancer cell lines in vitro. These compounds were more sensitive to BEL-7402 than other cell lines, particularly, cytotoxic activity of compounds 6b, 6d-f, 6p, 6s-u were in sub-micromolar scale. The highest cytotoxic potency against A549, HL-60 and MCF-7 was shown by 2-butoxy-4-chloro-5-fluoropyrimidine (5) with IC 50 values of 0.10, 1.66 and 0.59 μM, respectively. Compounds 6d and 6e were effective against MCF-7 with IC 50 9.73 μM and HL-60 with IC 50 8.83 μM, respectively

  19. Synthesis of some new substituted quinazolin-4-3H-ones as potent anticonvulsant agents

    International Nuclear Information System (INIS)

    Garg, N.; Chandra, T.; Lata, K.K.

    2009-01-01

    A new series of 3-(4-(2-(6,8-dibromo-3 (substituted phenyl)-4-oxo-3, 4-dihydroquinazolin-2-yl)methyl) hydrazinyl)thiazol-2-yl)-2-phenylthiazolidin-4-ones were synthesized and their structures were elucidated on the basis of elemental analyses and spectroscopic studies (IR, 1H-NMR). All the synthesized compounds 1-32 were screened for their anticonvulsant activity at a dose of 30 mg/kg. The compound 31 was found to be the most potent compound of this series showing 90% protection against MES. (author)

  20. FROM MRS WARREN’S PROFESSION TO PRESS CUTTINGS: THE WOMAN QUESTION IN GEORGE BERNARD SHAW’S PLAYS

    Directory of Open Access Journals (Sweden)

    Banu ÖĞÜNÇ

    2017-06-01

    Full Text Available George Bernard Shaw, who introduced social realism to the British stage, is considered to be the most significant playwright of the Victorian era. In his plays, he challenged the typical Victorian representation of female characters and introduced a new woman type who stands as a powerful and independent figure. Shaw’s female characters can be analysed in line with the suffragette movement, the fight given by British women to gain their right to vote. In this regard, Shaw’s play Mrs Warren’s Profession exemplifies a female character who can be considered as an advocate for female liberation and power. On the other hand, his play Press Cuttings, which was specifically written to support the suffragette movement, neither exemplifies the new woman image presented by Shaw in his plays nor contributes to the suffragette movement. Hence, this study aims to discuss the theme of the rights of women and to focus on George Bernard Shaw’s Mrs Warren’s Profession and Press Cuttings by means of Shaw’s involvement in and support for the suffragette movement from the Victorian to the Edwardian era.

  1. 40 CFR 721.981 - Substituted naphtholoazo-substituted naphthalenyl-substituted azonaphthol chromium complex.

    Science.gov (United States)

    2010-07-01

    ... naphthalenyl-substituted azonaphthol chromium complex. 721.981 Section 721.981 Protection of Environment...-substituted naphthalenyl-substituted azonaphthol chromium complex. (a) Chemical substance and significant new... naphtholoazo-substituted naphthalenyl-substituted azonaphthol chromium complex (PMN P-93-1631) is subject to...

  2. Alkyl group dependence on structure and magnetic properties in layered cobalt coordination polymers containing substituted glutarate ligands and 4,4'-bipyridine

    International Nuclear Information System (INIS)

    Nettleman, Joseph H.; Supkowski, Ronald M.; LaDuca, Robert L.

    2010-01-01

    Five two-dimensional divalent cobalt coordination polymers containing 4,4'-bipyridine (bpy) and substituted or unsubstituted glutarate ligands have been prepared hydrothermally and structurally characterized by single-crystal X-ray diffraction. [Co(mg)(bpy)] n (1, mg=3-methylglutarate) forms a (4,4) rhomboid grid structure based on the connection of {Co 2 (CO 2 ) 2 } dimeric units. Using the more sterically encumbered ligands 3,3-dimethylglutarate (dmg) and 3-ethyl, 3-methylglutarate (emg) generated {[Co(dmg)(bpy)(H 2 O)].2H 2 O} n (2) and {[Co(emg)(bpy)(H 2 O)].H 2 O} n (3), respectively. These complexes manifest {Co(CO 2 )} n chains linked into 2-D by aliphatic dicarboxylate and bpy ligands. The 'tied-back' substituted glutarate ligand 1,1-cyclopentanediacetate (cda) afforded [Co(cda)(bpy)] n (4), and the unsubstituted glutarate (glu) generated [Co(glu)(bpy)] n (5), both of which exhibit a topology similar to that of 1. The magnetic properties of complexes 1-4 were analyzed successfully with a recently developed phenomenological chain model accounting for both magnetic coupling (J) and zero-field splitting effects (D), even though 1 and 4 contain isolated, discrete {Co 2 (CO 2 ) 2 } dimers. The D parameter in this series varied between 21.8(8) and 48.0(9) cm -1 . However weak antiferromagnetic coupling was observed in 1 (J=-2.43(4) cm -1 ) and 4 (J=-0.89(2) cm -1 ), while weak ferromagnetic coupling appears to be operative in both 2 (J=0.324(5) cm -1 ) and 3 (J=0.24(1) cm -1 ). - Five two-dimensional divalent cobalt coordination polymers containing 4,4'-bipyridine (bpy) and substituted or unsubstituted glutarate ligands have been prepared and structurally characterized by single-crystal X-ray diffraction. Three contain dimeric {Co 2 (CO 2 ) 2 } units, while two manifest {Co(CO 2 )} n chains, depending on the steric bulk of the substituent. The magnetic properties of the complexes were analyzed successfully with a recently developed phenomenological chain model

  3. Nanostructurization effects in PVP-stabilized tetra-arsenic tetra-sulfide As{sub 4}S{sub 4} nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Shpotyuk, O., E-mail: olehshpotyuk@yahoo.com [Institute of Physics of Jan Dlugosz University in Czestochowa, 13/15, Al. Armii Krajowej, Czestochowa, 42200 (Poland); Vlokh Institute of Physical Optics, 23, Dragomanov Str., Lviv, 79005 (Ukraine); Scientific Research Company “Carat”, 202, Stryjska Str., 79031, Lviv (Ukraine); Bujňáková, Z.; Baláž, P. [Institute of Geotechnics of Slovak Academy of Sciences, 45, Watsonova Str., Košice, 04001 (Slovakia); Ingram, A. [Opole University of Technology, 75, Ozimska Str., Opole, 45370 (Poland); Demchenko, P. [Ivan Franko National University of Lviv, 1, Universytetska Str., 79000 Lviv (Ukraine); Kovalskiy, A. [Department of Physics & Astronomy, Austin Peay State University, Clarksville, TN, 37044 (United States); Vlcek, M. [Department of General and Inorganic Chemistry, Faculty of Chemistry, University of Pardubice, 532 10, Pardubice (Czech Republic); Shpotyuk, Ya. [Ivan Franko National University of Lviv, 1, Universytetska Str., 79000 Lviv (Ukraine); Centre for Innovation and Transfer of Natural Sciences and Engineering Knowledge, 1, Pigonia Str., 35310, Rzeszow (Poland); Cebulski, J.; Dziedzic, A. [Centre for Innovation and Transfer of Natural Sciences and Engineering Knowledge, 1, Pigonia Str., 35310, Rzeszow (Poland)

    2017-01-15

    Nanostructurization in three types of tetra-arsenic tetra-sulfide As{sub 4}S{sub 4} polymorphs composed by (1) preferential β-As{sub 4}S{sub 4}, (2) realgar α-As{sub 4}S{sub 4} and (3) admixture of As{sub 4}S{sub 4} in the form of β-realgar, pararealgar and intermediate χ-phase subjected to mechanochemical ball milling in a water solution of polyvinylpyrrolidone (PVP) are characterized with multiexperimental structure-sensitive probes. Void structure of pelletized As{sub 4}S{sub 4}-PVP nanocomposites is probed by positron annihilation lifetime spectroscopy complemented with atomic-sensitive techniques such as X-ray powder diffraction, Raman scattering and scanning electron microscopy with energy-dispersive X-ray spectroscopy. Appearance of arsenolite As{sub 2}O{sub 3} crystallites is character for all As{sub 4}S{sub 4} polymorphs affected by wet milling. Positron annihilation lifetime data considered in terms of substitution positron-positronium trapping confirm complicated nature of nanocomposites. Modified x3-x2-coupling decomposition algorithm developed in addition to unconstrained x3-term fitting procedure is applied to parameterize annihilation channels in these nanocomposites. Interfacial free-volume voids between neighboring nanoparticles in PVP environment are defined as most favorable trapping sites, they being rather loosely composed by As{sub 4}S{sub 4} crystallites in full respect to variety of crystallographic polymorphs used for milling. Detected annihilation channels are ascribed preferentially to intrinsic free-volume voids insensitive to trapping states at the surface of oxidized nanocomposites. - Highlights: • PVP-stabilized tetra-arsenic tetra-sulfide nanocomposites prepared by wet milling. • As{sub 4}S{sub 4}-PVP composites by complementary atomic-specific and deficient structure probes. • Surface oxidation due to crystalline arsenolite As{sub 2}O{sub 3} under wet milling. • Free-volume structure of PVP-stabilized As{sub 4}S{sub 4

  4. Structural, dielectric and gas sensing behavior of Mn substituted spinel MFe2O4 (M=Zn, Cu, Ni, and Co) ferrite nanoparticles

    Science.gov (United States)

    Ranjith Kumar, E.; Siva Prasada Reddy, P.; Sarala Devi, G.; Sathiyaraj, S.

    2016-01-01

    Spinel ferrite (MnZnFe2O4, MnCuFe2O4, MnNiFe2O4 and MnCoFe2O4) nanoparticles have been prepared by evaporation method. The annealing temperature plays an important role on changing particle size of the spinel ferrite nanoparticles was found out by X-ray diffraction and transmission electron microscopy. The role of manganese substitution in the spinel ferrite nanoparticles were also analyzed for different annealing temperature. The substitution of Mn also creates a vital change in dielectric properties have been measured in the frequency range of 100 kHz to 5 MHz. These spinel ferrites are decomposed to α-Fe2O3 after annealing above 550 °C in air. Through the characterization of the prepared powder, the effect of annealing temperature, chemical composition and preparation technique on the microstructure, particle size and dielectric properties of the Mn substituted spinel ferrite nanoparticles are discussed. Furthermore, Conductance response of Mn substituted MFe2O4 ferrite nanoparticles were measured by exposing the materials to reducing gas like liquefied petroleum gas (LPG).

  5. Interfacial elastic fingering in Hele-Shaw cells: A weakly nonlinear study

    KAUST Repository

    Carvalho, Gabriel D.

    2013-11-11

    We study a variant of the classic viscous fingering instability in Hele-Shaw cells where the interface separating the fluids is elastic, and presents a curvature-dependent bending rigidity. By employing a second-order mode-coupling approach we investigate how the elastic nature of the interface influences the morphology of emerging interfacial patterns. This is done by focusing our attention on a conventionally stable situation in which the fluids involved have the same viscosity. In this framework, we show that the inclusion of nonlinear effects plays a crucial role in inducing sizable interfacial instabilities, as well as in determining the ultimate shape of the pattern-forming structures. Particularly, we have found that the emergence of either narrow or wide fingers can be regulated by tuning a rigidity fraction parameter. Our weakly nonlinear findings reinforce the importance of the so-called curvature weakening effect, which favors the development of fingers in regions of lower rigidity. © 2013 American Physical Society.

  6. Universality Results for Multi-Layer Hele-Shaw and Porous Media Flows

    Science.gov (United States)

    Daripa, Prabir

    2012-11-01

    Saffman-Taylor instability is a well known viscosity driven instability of an interface. Motivated by a need to understand the effect of various injection policies currently in practice for chemical enhanced oil recovery, we study linear stability of displacement processes in a Hele-Shaw cell involving injection of an arbitrary number of immiscible fluid phases in succession. This is a problem involving many interfaces. Universal stability results have been obtained for this multi-layer (multi-region) flow in the sense that the results hold with arbitrary number of interfaces. These stability results have been applied to design injection policies that are considerably less unstable than the pure Saffman-Taylor case. In particular, we determine specific values of the viscosity of the fluid layers corresponding to smallest unstable band. Moreover, we discuss universal selection principle of optimal viscous profiles. The talk is based on following papers. Qatar National Fund (a member of the Qatar Foundation).

  7. Interfacial elastic fingering in Hele-Shaw cells: A weakly nonlinear study

    KAUST Repository

    Carvalho, Gabriel D.; Miranda, José A.; Gadê lha, Hermes

    2013-01-01

    We study a variant of the classic viscous fingering instability in Hele-Shaw cells where the interface separating the fluids is elastic, and presents a curvature-dependent bending rigidity. By employing a second-order mode-coupling approach we investigate how the elastic nature of the interface influences the morphology of emerging interfacial patterns. This is done by focusing our attention on a conventionally stable situation in which the fluids involved have the same viscosity. In this framework, we show that the inclusion of nonlinear effects plays a crucial role in inducing sizable interfacial instabilities, as well as in determining the ultimate shape of the pattern-forming structures. Particularly, we have found that the emergence of either narrow or wide fingers can be regulated by tuning a rigidity fraction parameter. Our weakly nonlinear findings reinforce the importance of the so-called curvature weakening effect, which favors the development of fingers in regions of lower rigidity. © 2013 American Physical Society.

  8. The effect of S-substitution at the O6-guanine site on the structure and dynamics of a DNA oligomer containing a G:T mismatch.

    Directory of Open Access Journals (Sweden)

    Elaine Ann Moore

    Full Text Available The effect of S-substitution on the O6 guanine site of a 13-mer DNA duplex containing a G:T mismatch is studied using molecular dynamics. The structure, dynamic evolution and hydration of the S-substituted duplex are compared with those of a normal duplex, a duplex with S-substitution on guanine, but no mismatch and a duplex with just a G:T mismatch. The S-substituted mismatch leads to cell death rather than repair. One suggestion is that the G:T mismatch recognition protein recognises the S-substituted mismatch (GS:T as G:T. This leads to a cycle of futile repair ending in DNA breakage and cell death. We find that some structural features of the helix are similar for the duplex with the G:T mismatch and that with the S-substituted mismatch, but differ from the normal duplex, notably the helical twist. These differences arise from the change in the hydrogen-bonding pattern of the base pair. However a marked feature of the S-substituted G:T mismatch duplex is a very large opening. This showed considerable variability. It is suggested that this enlarged opening would lend support to an alternative model of cell death in which the mismatch protein attaches to thioguanine and activates downstream damage-response pathways. Attack on the sulphur by reactive oxygen species, also leading to cell death, would also be aided by the large, variable opening.

  9. Homoaromatics as intermediates in the substitution reactions of 1,2,4,5-tetrazines with ammonia and hydrazine

    International Nuclear Information System (INIS)

    Counotte-Potman, A.D.

    1981-01-01

    This thesis describes some nucleophilic substitution reactions between the red 1,2,4,5-tetrazines and hydrazine-hydrate or ammonia. Special attention was paid to the occurrence of the Ssub(N) (ANRORC) mechanism in these substitution reactions. This mechanism comprises a sequence of reactions, involving the Addition of a Nucleopile to a heteroaromatic species, followed by a Ring-Opening and Ring Closure reaction to the substitution product. 3-Alkyl(aryl)-1,2,4,5-tetrazines were found to undergo a Chichibabin hydrazination into 6-hydrazino-3-alkyl(aryl)-1,2,4,5-tetrazines on treatment with hydrazine-hydrate. The first step in this reaction sequence was the formation of a homoaromatic sigma-adduct. Subsequently an open-chain intermediate was observed by NMR, on raising the temperature. Finally the hydrazino compound is formed by ring closure. This reaction sequence can be considered as an Ssub(N)(ANRORC) process. With 15 N-labelled hydrazine, only part of the label was found to be built in the 1,2,4,5-tetrazine ring of the 6-hydrazino compounds. This is the first example of a reaction in which both the hydrazino compound with the 15 N-label in the ring and with the 15 N-label in the exocyclic hydrazino group are formed according to the Ssub(N)(ANRORC) mechanism. (Auth.)

  10. Modulation in magnetic exchange interaction, core shell structure and Hopkinson's peak with chromium substitution into Ni0.75Co0.25Fe2O4 nano particles

    Science.gov (United States)

    Uday Bhasker, S.; Choudary, G. S. V. R. K.; Reddy, M. V. Ramana

    2018-05-01

    The ever growing applications and ever evolving challenges of magnetic nano particles has been motivating the researchers from various disciplines towards this area of magnetic nano particles. Cation substitutional effect on the magnetic structure of the nanoparticles forms a crucial aspect in their applications. Here the environmentally benign auto combustion method was employed to synthesize chromium substituted nickel cobalt ferrite (Ni0.75Co0.25Fe2-xCrxO4; x = 0, 0.10, 0.15) nano particles, from aqueous metal nitrate solutions. Chromium substitution has shown its effect on the structural, magnetic and electrical properties of Ni0.75Co0.25Fe2O4. Structural and phase analysis of the prepared samples show increased phase purity of ferrite sample with increasing Cr substitution. The TEM (Transmission Electron Microscope) image confirms the nano size of the particles, EDS (Energy dispersive X-ray Spectroscopy) has supported the stoichiometry of the prepared samples and FTIR (Fourier-transform infrared spectroscopic) analysis confirms the spinel structure and also suggests cation redistributions with chromium substitution. VSM (Vibrational Sample Magnetometer) is used to study the magnetic properties through magnetic hysteresis (M-H) loop and magnetic Hopkinson effect. All samples show hysteresis and show reduction in magnetic properties with increase in chromium content. The thermo magnetic study shows Hopkinson peak(s) in the magnetization vs. temperature (M-T) graph and also shows variation in the nature of Hopkinson peak with chromium substitution. Possible reasons for the changes in the nature of the peak are discussed.

  11. Superconductivity in alkaline earth-substituted La2CuO/sub 4-y/

    International Nuclear Information System (INIS)

    Bednorz, J.G.; Mueller, K.A.; Takashige, M.

    1987-01-01

    La 2 CuO/sub 4-y/ ceramics containing a few percent of Ca 2+ , Sr 2+ , and Ba 2+ ions have been prepared. Resistivity and susceptibility measurements exhibit superconductive onsets (as in earlier Ba 2+ -containing samples). The onset temperature La 2 CuO/sub 4-y/ with Sr 2+ is higher and its superconductivity-induced diamagnetism larger than that found with Ba 2+ and Ca 2+ . This is proof that the electronic change resulting from alkaline earth-doping, rather than the size effect, is responsible for superconductivity. The ionic radius of Sr 2+ is close to that of La 3+ for which it presumably substitutes

  12. The improved magnetic properties in phosphorus substituted Pr-Fe-P-B nanocomposites

    International Nuclear Information System (INIS)

    Jin, Z.Q.; Zhang, Y.; Wang, H.L.; Klaessig, A.; Bonder, M.; Hadjipanayis, G.C.

    2003-01-01

    Phosphorus substituted (Pr,Tb) 8 (Fe,Nb,Zr,P) 88 B 4 nanocomposites have been produced by melt-spinning. The effects of phosphorus substitution as well as wheel speed on the crystallization behavior and magnetic properties of the melt-spun samples have been investigated. With the substitution of phosphorus, the crystallization temperature of amorphous phase increases. The optimum wheel speed was found to be around 25 m/s for as-spun ribbons and 40 m/s for the annealed samples, both of which present excellent second quadrant hysteresis loop shapes due to the fine grain size of α-Fe which is around 20 nm. The addition of phosphorus also greatly improves the coercivity of Pr-Fe-B nanocomposites without a significant loss of saturation magnetization. A higher coercivity of 9.2 kOe in P-substituted samples was obtained as compared to 8.1 kOe in P-free samples. This is attributed to a narrower temperature span between the crystallization into TbCu 7 structure and the transformation into the 2:14:1 phase caused by the phosphorus substitution

  13. The O-H Bond Dissociation Energies of Substituted Phenols and Proton Affinities of Substituted Phenoxide Ions: A DFT Study

    Directory of Open Access Journals (Sweden)

    Tadafumi Uchimaru

    2002-04-01

    Full Text Available Abstract: The accurate O-H bond dissociation enthalpies for a series of meta and para substituted phenols (X-C6H4-OH, X=H, F, Cl, CH3, OCH3, OH, NH2, CF3, CN, and NO2 have been calculated by using the (ROB3LYP procedure with 6-311G(d,p and 6-311++G(2df,2p basis sets. The proton affinities of the corresponding phenoxide ions (XC6H4-O- have also been computed at the same level of theory. The effect of change of substituent position on the energetics of substituted phenols has been analyzed. The correlations of Hammett’s substituent constants with the bond dissociation enthalpies of the O-H bonds of phenols and proton affinities of phenoxide ions have been explored.

  14. Electron impact ionization mass spectra of 3-substituted-2-hydroxy-4(3H)-quinazolinones

    International Nuclear Information System (INIS)

    El Deen, I. M.; Abd El Fattah, M. E.

    2003-01-01

    2-Amino-2-hydroxy-4(3H)-quinazolinone (3) was prepared via condensation of 1 with hydrazine hydrate. Treatment of 3 with appropriate acid in POCl 3 , ethyl chloroacetate and activated olefinic compounds in DMF yielded the corresponding 3-(substituted)amino-2-hydroxy-4(3H)-quinazolinones 4,5 and 6. The electron impact ionization mass spectra of compounds 3 and 4 show a weak molecular ion peak and a base peak of m/z 146 resulting from a cleavage fragmentation. The compounds 5 and 6 give a characteristics fragmentation pattern with a very stable fragment of benzopyrazolone (m/z 132)

  15. Determination and structural correlation of the pKa values of p-substituted trans-2,3-epoxy-4-oxo-4-phenylbutanoic acids

    Directory of Open Access Journals (Sweden)

    I. JURANIC

    2000-11-01

    Full Text Available The pKa values for a series of eight p-substituted trans-2,3-epoxy-4-phenyl butanoic acids (p-substituted trans-b-aroylepoxyacrylic acids have been determined potentiometrically in aqueous media at 25°C at an ionic strength of 0.1 mol/dm3 (NaCl. The transmission of polar effects from the substituents on the phenyl nucleus to the carboxylic group through the side chain involving a carbonyl group and an epoxide ring was investigated. The pKa values were correlated with structure using the Hammett, Taft and Yukawa-Tsuno approaches. The Hammett r constant (0.34 was compared with analogue values for structurally similar acids.

  16. Treatment for GaSb surfaces using a sulphur blended (NH{sub 4}){sub 2}S/(NH{sub 4}){sub 2}SO{sub 4} solution

    Energy Technology Data Exchange (ETDEWEB)

    Murape, D.M., E-mail: Davison.Murape@nmmu.ac.za [Department of Physics, Nelson Mandela Metropolitan University, PO Box 77000, Port Elizabeth, 6031 (South Africa); Eassa, N.; Neethling, J.H. [Department of Physics, Nelson Mandela Metropolitan University, PO Box 77000, Port Elizabeth, 6031 (South Africa); Betz, R. [Department of Chemistry, Nelson Mandela Metropolitan University, PO Box 77000, Port Elizabeth, 6031 (South Africa); Coetsee, E.; Swart, H.C. [Department of Physics, University of the Free State, PO Box 339, Bloemfontein, 9300 (South Africa); Botha, J.R.; Venter, A. [Department of Physics, Nelson Mandela Metropolitan University, PO Box 77000, Port Elizabeth, 6031 (South Africa)

    2012-07-01

    A sulphur based chemical, [(NH{sub 4}){sub 2}S/(NH{sub 4}){sub 2}SO{sub 4}] to which S has been added, not previously reported for the treatment of (1 0 0) n-GaSb surfaces, is introduced and benchmarked against the commonly used passivants Na{sub 2}S{center_dot}9H{sub 2}O and (NH{sub 4}){sub 2}S. The surfaces of the treated material were studied by scanning electron microscopy (SEM), Auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS). It has been found that the native oxides present on the GaSb surface are more effectively removed when treated with ([(NH{sub 4}){sub 2}S/(NH{sub 4}){sub 2}SO{sub 4}] + S) than with (NH{sub 4}){sub 2}S or Na{sub 2}S{center_dot}9H{sub 2}O, as evidenced by the ratio of the O{sub 506eV} to Sb{sub 457eV} AES peaks. XPS results reveal that Sb{sub 2}S{sub 3}/Sb{sub 2}S{sub 5} 'replaces' Sb{sub 2}O{sub 3}/Sb{sub 2}O{sub 5}, suggesting that sulphur atoms substitute oxygen atoms in Sb{sub 2}O{sub 3}/Sb{sub 2}O{sub 5} to form Sb-S. It seems sulphurization only partially removes Ga{sub 2}O{sub 3}. Treatment with ([(NH{sub 4}){sub 2}S/(NH{sub 4}){sub 2}SO{sub 4}] + S) also results in a noteworthy improvement in the current-voltage (I-V) characteristics of Au/n-GaSb Schottky contacts compared to those fabricated on as-received material.

  17. Synthesis of carbasugars from aldonolactones, part III - A study on the allylic substitution of (1R,5R,8R)- and (1R,5R,8S)-8-hydroxy-2-oxabicyclo[3.3.0]oct-6-en-3-one derivatives - Preparation of (1S,2R,3R)-9-[2-hydroxy-3-(2-hydroxyethyl)cyclopent-4-en-1-yl]-9H-adenine

    DEFF Research Database (Denmark)

    Johansen, Steen Karsk; Lundt, Inge

    2001-01-01

    The palladium-catalyzed substitution of acylated (1R,5R,8R)- and (1R,SR,8S)-8-hydroxy-2-oxabicyclo[3.3.0] ones has been studied using a number of C- and N-nucleophiles, In all cases, the exo derivatives (8R) were found to be more reactive than the corresponding endo derivatives (8S). The reaction...... with these nucleophiles. Additionally, Mitsunobu substitution of (1R,5R,8R)-8-hydroxy-2-oxabicyclo[3.3.0]oct-B-en-3-one (3) with 6-chloropurine, followed by reduction of the lactone moiety and treatment with Liquid ammonia, gave the carbocyclic nucleoside (1S,2R,3R)-9-[2-hydroxy-3-(2-hydroxyethyl)cyclopent-4-en-1-yl]-9H...

  18. Approaches for introducing high molecular diversity in scaffolds: fast parallel synthesis of highly substituted 1H-quinolin-4-one libraries.

    Science.gov (United States)

    Kuznetsov, Vladimir; Gorohovsky, Sofia; Levy, Amalia; Meir, Simcha; Shkoulev, Vladimir; Menashe, Naim; Greenwald, Moshe; Aizikovich, Alexander; Ofer, Dror; Byk, Gerardo; Gellerman, Garry

    2004-01-01

    We have developed a two steps strategy for the parallel synthesis of highly diversified quinolin-ones. In the first step we have combined and improved different synthetic methods for generating quinolin-4-ones bearing four different substitutions at specific positions using round bottomed flasks. The synthesis was assessed for a large number of substituted quinolin-4-ones. In the second step, the improved method was adapted to a parallel array synthesis using a 12 positions carrousel as demonstrated for the synthesis of 42-variable quinolin-4-ones. The first combinatorial library set 14(a-x) was obtained with a chemical purity of more than 95% without purification, the second library set 15(a-r), which included two synthetic steps, needed combinatorial purification using an innovative parallel purifier. The proposed approach contributes to a more extensive diversification of molecular scaffolds in general and provides access to highly substituted quinolinones in particular.

  19. Effects of neodymium aliovalent substitution on the structure and electrochemical performance of LiFePO4

    International Nuclear Information System (INIS)

    Zhao Xian; Tang Xiaozhen; Zhang Li; Zhao Minshou; Zhai Jing

    2010-01-01

    LiFe 1-x Nd x PO 4 /C (x = 0-0.08) cathode material was synthesized using a solid-state reaction. The synthesis conditions were optimized by thermal analysis of the precursor and magnetic properties of LiFePO 4 /C. The structure and electrochemical performances of the material were studied using XRD, FE-SEM, EDS, electrochemical impedance spectroscopy and galvanostatic charge-discharge. The results show that a small amount of aliovalent Nd 3+ ion-dopant substitution on Fe 2+ ions can effectively reduce the particle size of LiFePO 4 /C. Cell parameters of LiFe 1-x Nd x PO 4 (x = 0.04-0.08) were calculated, and the results showed that LiFe 1-x Nd x PO 4 /C had the same olivine structure as LiFePO 4 . LiFe 0.4 Nd 0.6 PO 4 /C delivers the discharge capacity of 165.2 mAh g -1 at rate of 0.2 C and the capacity retention rate is 92.8% after 100 cycles. Charge-transfer resistance decreases with the addition of glucose and Nd 3+ ions. Poly(cyclotriphosphazene-co-4,4'-sulfonyldiphenol) (PZS) was synthesized and PZS nanorods were used as a carbon source to coat LiFePO 4 . All of the results show that aliovalent doping substitution of Fe in LiFePO 4 is well tolerated.

  20. Oxidation of substituted alkyl radicals by IrCl62-, Fe(CN)63-, and MnO4- in aqueous solution. Electron transfer versus chlorine transfer from IrCl62-

    International Nuclear Information System (INIS)

    Steenken, S.; Neta, P.

    1982-01-01

    Alkyl radicals substituted at C/sub α/ by alkyl, carboxyl, hydroxyl, alkoxyl, and chlorine react in aqueous solutions with Ir/sup IV/Cl 6 2- to yield Ir(III) species. In the case of substitution by hydroxyl and alkoxyl, the rate constants are in the diffusion-controlled range ((4-6) x 10 9 M -1 s -1 ) and the reaction proceeds by electron transfer. In the case of ethyl, methyl, carboxymethyl, and chloromethyl radicals the rate constants range from 3.1 x 10 9 for ethyl to 2.8 x 10 7 M -1 s -1 for trichloromethyl and the reaction proceeds by chlorine transfer from IrCl 6 2- to the alkyl radical. With isopropyl and tert-butyll radicals the reaction proceeds by both electron and chlorine transfer. Alkyl radicals also react with Fe(CN) 6 3- . The rate constants increase strongly with increasing alkylation at C/sub α/ from 5 x 10 6 for methyl to 3.6 x 10 9 M -1 s -1 for tert-butyl, indicating that the transition state for the reaction is highly polar. Rate constants for reaction of MnO 4 - with alkyl radicals are of the order 10 9 M -1 s -1 . 4 figures, 1 table

  1. Non-Imidazole Histamine H₃ Ligands. Part VII. Synthesis, In Vitro and In Vivo Characterization of 5-Substituted-2-thiazol-4-n-propylpiperazines.

    Science.gov (United States)

    Guryn, Roman; Staszewski, Marek; Stasiak, Anna; McNaught Flores, Daniel; Fogel, Wiesława Agnieszka; Leurs, Rob; Walczyński, Krzysztof

    2018-02-03

    H₃ receptors present on histaminergic and non-histaminergic neurons, act as autoreceptors or heteroreceptors controlling neurotransmitter release and synthesis. Previous, studies have found that the compound N -methyl- N -3-phenylalkyl-2-[2-(4-n-propylpiperazin-1-yl)-1,3-thiazol-5-yl]ethan-1-amine ( ADS-531, 2c ) exhibits high in vitro potency toward H₃ guinea pig jejunal receptors, with pA₂ = 8.27. To optimize the structure of the lead compound ADS-531 , a series of 5-substituted-2-thiazol-4- n -propylpiperazines 3 were synthesized and subjected to in vitro pharmacological characterization; the alkyl chain between position 2 of the thiazole ring and the terminal secondary N -methylamino function was elongated from three to four methylene groups and the N -methylamino functionality was substituted by benzyl-, 2-phenylethyl-, and 3-phenyl-propyl- moieties. SAR studies on novel non-imidazole, 5-substituted-2-thiazol-4- n -propyl-piperazines 3 showed that the most active compound 3a (pA₂ = 8.38), additionally possessed a weak competitive H₁-antagonistic activity. Therefore, compound ADS-531 , which did not exhibit any H₁-antagonistic activity, was chosen for further evaluation for its affinity to the recombinant rat and human histamine H₃ receptors (rH₃R and hH₃R, respectively). ADS-531 exhibited nanomolar affinity for both rH₃R and hH₃R receptors. It was also shown that, ADS-531 given subchronically to rats (s.c. 3 mg/kg, 5 days) penetrated the brain, where it affected dopamine, noradrenaline and serotonin concentration; however, it did not affect histamine concentration nor feeding behavior.

  2. Electron-Rich 4-Substituted Spirobifluorenes: Toward a New Family of High Triplet Energy Host Materials for High-Efficiency Green and Sky Blue Phosphorescent OLEDs.

    Science.gov (United States)

    Quinton, Cassandre; Thiery, Sébastien; Jeannin, Olivier; Tondelier, Denis; Geffroy, Bernard; Jacques, Emmanuel; Rault-Berthelot, Joëlle; Poriel, Cyril

    2017-02-22

    We report herein a detailed structure-properties relationship study of the first examples of electron-rich 4-substituted spirobifluorenes for organic electronic applications, namely, 4-phenyl-N-carbazole-spirobifluorene (4-PhCz-SBF) and 4-(3,4,5-trimethoxyphenyl)-spirobifluorene (4-Ph(OMe) 3 -SBF). The incorporation of the electron-rich moieties in the ortho position of the biphenyl linkage (position C4) induces unique properties, very different from those previously described in the literature for this family of semiconductors. Both dyes can be readily synthesized, possess high triplet energies and excellent thermal stability, and their HOMO energy levels are highly increased compared to those of other 4-substituted SBFs. We also provide in this work the first rationalization of the peculiar fluorescence of 4-substituted SBFs. Finally, the present dyes have been successfully incorporated as host in green and blue phosphorescent organic light-emitting diodes with high performance either for the green (EQE of 20.2%) or the blue color (EQE of 9.6%). These performances are, to the best of our knowledge, among the highest reported to date for 4-substituted SBF derivatives.

  3. Improved superconducting properties of La{sub 3}Co{sub 4}Sn{sub 13} with indium substitution

    Energy Technology Data Exchange (ETDEWEB)

    Neha, P.; Srivastava, P. [School of Physical Sciences, Jawaharlal Nehru University, New Delhi 110067 (India); Jha, R. [School of Physical Sciences, Jawaharlal Nehru University, New Delhi 110067 (India); National Physical Laboratory, New Delhi 110012 (India); Shruti [School of Physical Sciences, Jawaharlal Nehru University, New Delhi 110067 (India); Awana, V.P.S. [National Physical Laboratory, New Delhi 110012 (India); Patnaik, S., E-mail: spatnaik@mail.jnu.ac.in [School of Physical Sciences, Jawaharlal Nehru University, New Delhi 110067 (India)

    2016-04-25

    We report two fold increase in superconducting transition temperature of La{sub 3}Co{sub 4}Sn{sub 13} by substituting indium at the tin site. The transition temperature of this skutterudite related compound is observed to increase from 2.5 K to 5.1 K for 10% indium substituted sample. The band structure and density of states calculations also indicate such a possibility. The compounds exhibit type-II superconductivity and the values of lower critical field (H{sub c1}), upper critical field (H{sub c2}), Ginzburg–Landau coherence length (ξ), penetration depth (λ) and GL parameter (κ) are estimated to be 0.0028 T, 0.68 T, 21.6 nm, 33.2 nm and 1.53 respectively for La{sub 3}Co{sub 4}Sn{sub 11.7}In{sub 1.3}. Hydrostatic external pressure leads to decrease in transition temperature and the calculated pressure coefficient is −0.311 K/GPa. Flux pinning and vortex activation energies also improved with indium addition. Only positive frequencies are observed in phonon dispersion curve that relate to the absence of charge density wave or structural instability in the normal state. - Highlights: • Superconducting transition temperature of La{sub 3}Co{sub 4}Sn{sub 13} increases two fold by indium substitution. • Band structure and all basic superconducting parameters (e.g,. H{sub c1}, H{sub c2}, ξ,λ and κ are ascertained. • Dependence of superconducting properties under external pressure is studied.

  4. 4s24p3--4s4p4 and 4s24p3--4s2fp25s transitions in Y VII, Zr VIII, Nb IX, and MoX

    International Nuclear Information System (INIS)

    Reader, J.; Acquista, N.

    1981-01-01

    Spectra of ionized Y, Zr, Nb, and Mo have been observed in sliding-spark and triggered-spark discharges on 10.7-m normal- and grazing-incidence spectrographs at the National Bureau of Standards in Washington, D. C. From these observations the 4s 2 4p 3 --4s4p 4 transitions in Y VII, Zr VIII, Nb IX, and Mo X have been identified. The 4s 2 4p 3 --4s 2 4p 2 5s transitions in Y VII-Mo X, previously identified by Rahimullah et al. [Phys. Scr. 14, 221--223 (1976); 18, 96--106 (1978)], have been confirmed. In Y VII the 4s 2 4p 3 --4s 2 4p 2 6s and 4s4p 4 --4p 5 transition also have been found. The parameters obtained from least-squares fits to the energy levels are compared with Hartree--Fock calculations. Preliminary values of the ionization energies have been determined as 110.02 +- 0.15 eV for Y VII, 133.7 +- 0.5 eV for Zr VIII, 159.2 +- 0.7 eV for Nb IX, and 186.4 +- 1.2 eV for Mo X

  5. Steam Reforming of CH4 Using Ni- Substituted Pyrochlore Catalysts

    Science.gov (United States)

    Haynes, Daniel J.

    The steam reforming of methane (SMR) continues to remain an important industrial reaction for large-scale production of H2 as well as synthesis gas mixtures which can be used for the production of useful chemicals (e.g. methanol). Although SMR is a rather mature technology, traditional nickel based catalysts used industrially are subjected to severe temperatures and reaction conditions, which lead to irreversible activity loss through sintering, support collapse, and carbon formation. Pyrochlore-based mixed oxide have been identified as refractory materials that can be modified through the substitution of catalytic metals and other promoting species into the structure to mitigate these issues causing deactivation. For this study, a lanthanum zirconate pyrochlore catalyst was substituted with Ni to determine whether the oxide structure could effectively stabilize the activity of the catalytic metal during the SMR. The effect of different variables including calcination temperature, a comparison of a substituted versus supported Ni pyrochlore catalyst, Ni weight loading, and Sr promotion have been evaluated to determine the location of the Ni in the structure, and their effect on catalytic behavior. It was revealed that the effect of calcination temperature on a 6wt% Ni substituted pyrochlore produced by the Pechini method demonstrated very little Ni was soluble in the pyrochlore lattice. It was further revealed that by XRD, TEM, and atom probe tomography that, despite the metal loading, Ni exsolves from the structure upon crystallization of the pyrochlore at 700°C, and forms NiO at the surface and grain boundaries. An additional separate La2ZrNiO6 perovskite phase also began to form at higher temperatures (>800°C). Increasing calcination temperature was found to lead to slight sintering of the NiO at the surface, which made the NiO more reducible. Meanwhile decreasing the Ni weight loading was found to produce a lower reduction temperature due to the presence of

  6. Synthesis and pharmacological evaluation of N-substituted 2-(2-oxo-2H-chromen-4-yloxy)propanamide as cyclooxygenase inhibitors.

    Science.gov (United States)

    Rambabu, D; Mulakayala, Naveen; Ismail; Kumar, K Ravi; Kumar, G Pavan; Mulakayala, Chaitanya; Kumar, Chitta Suresh; Kalle, Arunasree M; Rao, M V Basaveswara; Oruganti, Srinivas; Pal, Manojit

    2012-11-01

    A series of novel N-substituted 2-(2-oxo-2H-chromen-4-yloxy)propanamide derivatives were synthesized via converting the readily available 4-hydroxy coumarin to the corresponding ethyl 2-(2-oxo-2H-chromen-4-yloxy)propanoate followed by hydrolysis and then reacting with different substituted amines. The molecular structures of two representative compounds, that is, 3 and 5l were confirmed by single crystal X-ray diffraction study. All the compounds synthesized were evaluated for their cyclooxygenase (COX) inhibiting properties in vitro. The compound 5i showed balanced selectivity towards COX-2 over COX-1 inhibition and good docking scores when docked into the COX-2 protein. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. Studies of alpha-helicity and intersegmental interactions in voltage-gated Na+ channels: S2D4.

    Directory of Open Access Journals (Sweden)

    Zhongming Ma

    2009-11-01

    Full Text Available Much data, including crystallographic, support structural models of sodium and potassium channels consisting of S1-S4 transmembrane segments (the "voltage-sensing domain" clustered around a central pore-forming region (S5-S6 segments and the intervening loop. Voltage gated sodium channels have four non-identical domains which differentiates them from the homotetrameric potassium channels that form the basis for current structural models. Since potassium and sodium channels also exhibit many different functional characteristics and the fourth domain (D4 of sodium channels differs in function from other domains (D1-D3, we have explored its structure in order to determine whether segments in D4 of sodium channels differ significantly from that determined for potassium channels. We have probed the secondary and tertiary structure and the role of the individual amino acid residues of the S2D4 of Na(v1.4 by employing cysteine-scanning mutagenesis (with tryptophan and glutamine substituted for native cysteine. A Fourier transform power spectrum of perturbations in free energy of steady-state inactivation gating (using midpoint potentials and slopes of Boltzmann equation fits of channel availability, h(infinity-V plots indicates a substantial amount of alpha-helical structure in S2D4 (peak at 106 degrees, alpha-Periodicity Index (alpha-PI of 3.10, This conclusion is supported by alpha-PI values of 3.28 and 2.84 for the perturbations in rate constants of entry into (beta and exit from (alpha fast inactivation at 0 mV for mutant channels relative to WT channels assuming a simple two-state model for transition from the open to inactivated state. The results of cysteine substitution at the two most sensitive sites of the S2D4 alpha-helix (N1382 and E1392C support the existence of electrostatic network interactions between S2 and other transmembrane segments within Na(v1.4D4 similar to but not identical to those proposed for K+ channels.

  8. Synthesis of Some O-Substituted Derivatives of Natural 6-hydroxymethyl-4-methoxy-2H-pyran-2-one (opuntiol)

    International Nuclear Information System (INIS)

    Shahzadi, T.; Akhtar, M.; Rehman, A.; Riaz, T.; Ashraf, M.

    2013-01-01

    This manuscript reports the synthesis of a series of new O-substituted derivatives of opuntiol (1) which is a naturally occurring compound isolated from a plant Opuntia dillenii Haw belonging to family Cactaceae. These derivatives 3a-t, were characterized by FAB-MS, IR, and 1H-NMR and then screened against acetylcholinesterase, butyrylcholinesterase, lipoxygenase and H-chymotrypsin enzymes. The screening results revealed that 6-(acetyloxy) methyl- 4-methoxy-2H-pyran-2-one (3b) and N-(2,5-dimethylphenyl)-2-((4-methoxy-6-oxo-2H-pyran-2-yl) methoxy)acetamide (3p) were found to be the inhibitor of butyrylcholinesterase while 6-(acetyloxy) methyl- 4-methoxy-2H-pyran-2-one (3b), 6-(ethoxymethyl)-4-methoxy-2H-pyran-2-one (3c), 4-methoxy-6-((phenylmethoxy)methyl)-2H-pyran-2-one (3g), 6-((2-bromoethyloxy)methyl)-4-methoxy-2H-pyran-2-one (3j), N-(5-chloro-2-ethoxyphenyl)-2-((4-methoxy-6-oxo-2H-pyran-2-yl)methoxy) acetamide (3r), N-(3,4-dimethylphenyl)-2-((4-methoxy-6-oxo-2H-pyran-2-yl)methoxy)acetamide (3s) N-(3,5-dimethylphenyl)-2-((4-methoxy-6-oxo-2H-pyran-2-yl)methoxy)acetamide (3t) were found to be active against H-chymotrypsin and among these 3s was the good inhibitor of this enzyme having IC50 value of 142.71 +- 0.22 micro moles/L. (author)

  9. Nature of the Electrochemical Properties of Sulphur Substituted LiMn2O4 Spinel Cathode Material Studied by Electrochemical Impedance Spectroscopy

    Directory of Open Access Journals (Sweden)

    Monika Bakierska

    2016-08-01

    Full Text Available In this work, nanostructured LiMn2O4 (LMO and LiMn2O3.99S0.01 (LMOS1 spinel cathode materials were comprehensively investigated in terms of electrochemical properties. For this purpose, electrochemical impedance spectroscopy (EIS measurements as a function of state of charge (SOC were conducted on a representative charge and discharge cycle. The changes in the electrochemical performance of the stoichiometric and sulphur-substituted lithium manganese oxide spinels were examined, and suggested explanations for the observed dependencies were given. A strong influence of sulphur introduction into the spinel structure on the chemical stability and electrochemical characteristic was observed. It was demonstrated that the significant improvement in coulombic efficiency and capacity retention of lithium cell with LMOS1 active material arises from a more stable solid electrolyte interphase (SEI layer. Based on EIS studies, the Li ion diffusion coefficients in the cathodes were estimated, and the influence of sulphur on Li+ diffusivity in the spinel structure was established. The obtained results support the assumption that sulphur substitution is an effective way to promote chemical stability and the electrochemical performance of LiMn2O4 cathode material.

  10. Synthesis of substituted 1,4-diazepines and 1,5-benzodiazepines using an efficient heteropolyacid-catalyzed procedure.

    Science.gov (United States)

    Kaoua, Rachedine; Bennamane, Norah; Bakhta, Saliha; Benadji, Sihame; Rabia, Cherifa; Nedjar-Kolli, Bellara

    2010-12-28

    An efficient and improved procedure for the synthesis of 1,4-diazepine and 1,5-benzodiazepine derivatives via the reaction of ketimine intermediates with aldehydes in the presence of Keggin-type heteropolyacids (HPAs) was developed. High yields and short reaction times were obtained for both electron-releasing and electron-withdrawing substituted 1,4-diazepine  and 1,5-benzodiazepines derivatives.

  11. Synthesis of Substituted 1,4-Diazepines and 1,5-Benzodiazepines Using an Efficient Heteropolyacid-Catalyzed Procedure

    Directory of Open Access Journals (Sweden)

    Sihame Benadji

    2010-12-01

    Full Text Available An efficient and improved procedure for the synthesis of 1,4-diazepine and 1,5-benzodiazepine derivatives via the reaction of ketimine intermediates with aldehydes in the presence of Keggin-type heteropolyacids (HPAs was developed. High yields and short reaction times were obtained for both electron-releasing and electron-withdrawing substituted 1,4-diazepine  and 1,5-benzodiazepines derivatives.

  12. Thermoelectric properties of a Mn substituted synthetic tetrahedrite.

    Science.gov (United States)

    Chetty, Raju; D S, Prem Kumar; Rogl, Gerda; Rogl, Peter; Bauer, Ernst; Michor, Herwig; Suwas, Satyam; Puchegger, Stephan; Giester, Gerald; Mallik, Ramesh Chandra

    2015-01-21

    Tetrahedrite compounds Cu(12-x)Mn(x)Sb4S13 (0 ≤x≤ 1.8) were prepared by solid state synthesis. A detailed crystal structure analysis of Cu10.6Mn1.4Sb4S13 was performed by single crystal X-ray diffraction (XRD) at 100, 200 and 300 K confirming the noncentrosymmetric structure (space group I4[combining macron]3m) of a tetrahedrite. The large atomic displacement parameter of the Cu2 atoms was described by splitting the 12e site into a partially and randomly occupied 24g site (Cu22) in addition to the regular 12e site (Cu21), suggesting a mix of dynamic and static off-plane Cu2 atom disorder. Rietveld powder XRD pattern and electron probe microanalysis revealed that all the Mn substituted samples showed a single tetrahedrite phase. The electrical resistivity increased with increasing Mn due to substitution of Mn(2+) at the Cu(1+) site. The positive Seebeck coefficient for all samples indicates that the dominant carriers are holes. Even though the thermal conductivity decreased as a function of increasing Mn, the thermoelectric figure of merit ZT decreased, because the decrease of the power factor is stronger than the decrease of the thermal conductivity. The maximum ZT = 0.76 at 623 K is obtained for Cu12Sb4S13. The coefficient of thermal expansion 13.5 ± 0.1 × 10(-6) K(-1) is obtained in the temperature range from 460 K to 670 K for Cu10.2Mn1.8Sb4S13. The Debye temperature, Θ(D) = 244 K for Cu10.2Mn1.8Sb4S13, was estimated from an evaluation of the elastic properties. The effective paramagnetic moment 7.45 μB/f.u. for Cu10.2Mn1.8Sb4S13 is fairly consistent with a high spin 3d(5) ground state of Mn.

  13. Ultrafast non-adiabatic dynamics of methyl substituted ethylenes: The π3s Rydberg state

    Science.gov (United States)

    Wu, Guorong; Boguslavskiy, Andrey E.; Schalk, Oliver; Schuurman, Michael S.; Stolow, Albert

    2011-10-01

    Excited state unimolecular reactions of some polyenes exhibit localization of their dynamics at a single ethylenic double bond. Here we present studies of the fundamental photophysical processes in the ethylene unit itself. Combined femtosecond time-resolved photoelectron spectroscopy (TRPES) and ab initio quantum chemical calculations was applied to the study of excited state dynamics in cis-butene, trans-butene, trimethylethylene, and tetramethylethylene, following initial excitation to their respective π3s Rydberg states. The wavelength dependence of the π3s Rydberg state dynamics of tetramethylethylene was investigated in more detail. The π3s Rydberg to ππ* valence state decay rate varies greatly with substituent: the 1,2-di- and tri-methyl substituted ethylenes (cis-butene, trans-butene, and trimethylethylene) show an ultrafast decay (˜20 fs), whereas the fully methylated tetramethylethylene shows a decay rate of 2 to 4 orders of magnitude slower. These observations are rationalized in terms of topographical trends in the relevant potential energy surfaces, as found from ab initio calculations: (1) the barrier between the π3s state and the ππ* state increases with increasing methylation, and (2) the π3s/ππ* minimum energy conical intersection displaces monotonically away from the π3s Franck-Condon region with increasing methylation. The use of systematic methylation in combination with TRPES and ab initio computation is emerging as an important tool in discerning the excited state dynamics of unsaturated hydrocarbons.

  14. Intertemporal Substitution and Labour Supply of Bosnian SME’s

    Directory of Open Access Journals (Sweden)

    Ada Šabić-Lipovača

    2016-08-01

    Full Text Available Our paper aims at testing the intertemporal substitution hypothesis (ISH for small and medium enterprises (SMEs in Bosnia and Herzegovina. The hypothesis predicts a positive relationship between the hours worked and the transitory changes in wages. We tested the hypothesis using the data on the daily income and worked hours collected via the survey questionnaire among small entrepreneurs in North-Western Bosnia and Herzegovina. The estimated wage elasticities turned out to be positive and different from zero, according to which it appears that the hypothesis of negative wage elasticities was not backed up by the empirical evidence. Our findings imply that the intertemporal labour substitution hypothesis found evidence and that we can reject the daily targeting hypothesis. We also argue that Bosnian entrepreneurs tend to pursue profits across working days because their main motive for running a business is the accumulation of capital and wealth, so that they follow the pattern of intertemporal labour substitution. The findings can be explained by an unfavourable business climate in Bosnia and Herzegovina, which is a result of a long-lasting transition process the country is still undergoing.

  15. An Empirical Examination of Symptom Substitution Associated with Behavior Therapy for Tourette's Disorder

    Science.gov (United States)

    Peterson, Alan L.; McGuire, Joseph F.; Wilhelm, Sabine; Piacentini, John; Woods, Douglas W.; Walkup, John T.; Hatch, John P.; Villarreal, Robert; Scahill, Lawrence

    2018-01-01

    Over the past 6 decades, behavior therapy has been a major contributor to the development of evidence-based psychotherapy treatments. However, a longstanding concern with behavior therapy among many nonbehavioral clinicians has been the potential risk for symptom substitution. Few studies have been conducted to evaluate symptom substitution in response to behavioral treatments, largely due to measurement and definitional challenges associated with treated psychiatric symptoms. Given the overt motor and vocal tics associated with Tourette’s disorder, it presents an excellent opportunity to empirically evaluate the potential risk for symptom substitution associated with behavior therapy. The present study examined the possible presence of symptom substitution using 4 methods: (1) the onset of new tic symptoms; (2) the occurrence of adverse events; (3) change in tic medications; and (4) worsening of co-occurring psychiatric symptoms. Two hundred twenty-eight participants with Tourette’s disorder or persistent motor or vocal tic disorders were randomly assigned to receive behavioral therapy or supportive therapy for tics. Both therapies consisted of 8 sessions over 10 weeks. Results indicated that participants treated with behavior therapy were not more likely to have an onset of new tic symptoms, experience adverse events, increase tic medications, or have an exacerbation in co-occurring psychiatric symptoms relative to participants treated with supportive therapy. Further analysis suggested that the emergence of new tics was attributed with the normal waxing and waning nature of Tourette’s disorder. Findings provide empirical support to counter the longstanding concern of symptom substitution in response to behavior therapy for individuals with Tourette's Disorder. PMID:26763495

  16. Novel One-Pot Access to 3,3-bis(3-hydroxy-5-substituted-1H-pyrazol-4-yl) indolin-2-ones

    International Nuclear Information System (INIS)

    Lin, Y.; Fu, Z.; Song, Q.; Shen, T.

    2016-01-01

    Sodium bicarbonate was applied as catalyst for the synthesis of 3,3-bis(3-hydroxy-5-substituted-1H-pyrazol-4-yl)indolin-2-ones via the reaction of isatins, hydrazine hydrate and ethyl acetoacetate or ethyl benzoylacetate. This reaction was performed in ethanol at 78 degree C, giving 3,3-bis(3-hydroxy-5-substituted-1H-pyrazol-4-yl)indolin-2-one derivatives in good to excellent yields. The structure of 5-bromo-3,3-bis(3-hydroxy-5-methyl-1H-pyrazol-4-yl) indolin-2-one was unambiguously confirmed by X-ray single crystal structure analysis and a plausible reaction mechanism is also proposed. (author)

  17. Exposure to the BPA-Substitute Bisphenol S Causes Unique Alterations of Germline Function.

    Directory of Open Access Journals (Sweden)

    Yichang Chen

    2016-07-01

    Full Text Available Concerns about the safety of Bisphenol A, a chemical found in plastics, receipts, food packaging and more, have led to its replacement with substitutes now found in a multitude of consumer products. However, several popular BPA-free alternatives, such as Bisphenol S, share a high degree of structural similarity with BPA, suggesting that these substitutes may disrupt similar developmental and reproductive pathways. We compared the effects of BPA and BPS on germline and reproductive functions using the genetic model system Caenorhabditis elegans. We found that, similarly to BPA, BPS caused severe reproductive defects including germline apoptosis and embryonic lethality. However, meiotic recombination, targeted gene expression, whole transcriptome and ontology analyses as well as ToxCast data mining all indicate that these effects are partly achieved via mechanisms distinct from BPAs. These findings therefore raise new concerns about the safety of BPA alternatives and the risk associated with human exposure to mixtures.

  18. Optical properties of new 5-(4-phenylethynyl)-substituted-1,10-phenanthroline derivatives

    International Nuclear Information System (INIS)

    Guerin, Juliette; Aronica, Christophe; Boeuf, Gaelle; Chauvin, Jerome; Moreau, Juliette; Lemercier, Gilles

    2011-01-01

    The synthesis and optical properties of a novel family of 5-substituted-1,10-phenanthroline derivatives are reported herein. One carbon-carbon triple-bond function was introduced using a Sonogashira cross-coupling reaction. The effects on optical properties, of the substitution with electro-withdrawing or -donating substituents in the 5th position of the 1,10-phenanthroline are investigated. Experimental chemical structure-polarisability relationship is analyzed according to the Lippert-Mataga correlation and compared to a theoretical study carried out with DFT calculations. These compounds are promising candidates for a fine-tuning of the internal charge-transfers but also as potential nonlinear chromophores and ligands within multifunctional coordination complexes. - Highlights: → Synthesis and optical properties of new 5-substituted-1,10-phenanthroline derivatives. → Sonogashira reaction was used for the substitution. → Structure-polarisability relationship analyzed according to Lippert-Mataga correlation. → Theoretical study was carried out with DFT calculations. → Fine-tuning of the internal charge-transfers within nonlinear compounds.

  19. High-temperature Thermoelectric and Microstructural Characteristics of Ga Substituted on the Co-site in Cobalt-based Oxides

    DEFF Research Database (Denmark)

    Van Nong, Ngo; Yanagiya, S.; Sonne, Monica

    2011-01-01

    The effects of Ga substitution on the Co-site on the high-temperature thermoelectric properties and microstructure are investigated for the misfitlayered Ca3Co4O9 and the complex perovskite-related Sr3RECo4O10.5 (RE = rare earth) cobalt-based oxides. For both systems, substitution of Ga for Co...... results in a simultaneous increase in the Seebeck coefficient (S) and the electrical conductivity (σ), and the influence is more significant in the high temperature region. The power factor (S 2 σ) is thereby remarkably improved by Ga substitution, particularly at high temperatures. Texture factor......0.05O9 shows the best ZT value of 0.45 at 1200 K, which is about 87.5% higher than the nondoped one, a considerable improvement....

  20. Structural and magnetic properties correlated with cation distribution of Mo-substituted cobalt ferrite nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Heiba, Z.K. [Faculty of Science, Taif University, P.O. Box: 888, Al-Haweiah, Taif (Saudi Arabia); Physics Department, Faculty of Science, Ain Shams University, Cairo (Egypt); Mostafa, Nasser Y., E-mail: nmost69@yahoo.com [Faculty of Science, Taif University, P.O. Box: 888, Al-Haweiah, Taif (Saudi Arabia); Chemistry Department, Faculty of Science, Suez Canal University, Ismailia 41522 (Egypt); Abd-Elkader, Omar H. [Department of Zoology, Science College, King Saud University, P.O. Box 2455, Riyadh 11451 (Saudi Arabia); Electron Microscope and Thin Films Department, National Research Center (NRC), El-Behooth Street, Dokki, Cairo 12622 (Egypt)

    2014-11-15

    Mo-substituted cobalt ferrite nanoparticles; CoFe{sub 2−2x}Mo{sub x}O{sub 4} (0.0≤x≤0.3) were prepared by a one-step solution combustion synthesis technique. The reactants were metal nitrates and glycine as a fuel. The samples were characterized using an X-ray diffraction (XRD), a transmission electron microscope (TEM) and a vibrating sample magnetometer (VSM). XRD analysis revealed a pure single phase of cubic spinel ferrites for all samples with x up to 0.3. The lattice parameter decreases with Mo{sup 6+} substitution linearly up to x=0.15, then nonlinearly for x≥0.2. Rietveld analysis and saturation magnetization (M{sub s}) revealed that Mo{sup 6+} replaced Fe{sup 3+} in the tetrahedral A-sites up to x=0.15, then it replaced Fe{sup 3+} in both A-sites and B-sites for x≥0.2. The saturation magnetization (M{sub s}) increases with increasing Mo{sup 6+} substitution up to x=0.15 then decreases. The crystallite size decreased while the microstrain increased with increasing Mo{sup 6+} substitution. Inserting Mo{sup 6+} produces large residents of defects and cation vacancies. - Highlights: • Nano-sized Mo-substituted cobalt ferrite CoFe{sub 2−2x}Mo{sub x}O{sub 4} (0.0≤x≤0.3) were prepared by solution combustion. • The change in M{sub s} with increasing Mo-substitution was investigated. • The cations distributions of ferrites were obtained from Rietveld analysis. • Inserting Mo{sup 6+} produces large residents of defects and cation vacancies.

  1. Effect of Gd3+ substitution on structural, magnetic, dielectric and optical properties of nanocrystalline CoFe2O4

    Science.gov (United States)

    Joshi, Seema; Kumar, Manoj; Chhoker, Sandeep; Kumar, Arun; Singh, Mahavir

    2017-03-01

    Nanoparticles of CoGdxFe2-xO4 with x=0.0, 0.03, 0.05, 0.07, 0.10 and 0.15 were synthesized by co-precipitation method. Gd3+ substitution effect on different properties of nanocrystalline CoFe2O4 has been studied. X-ray diffraction and Raman spectroscopy confirmed the formation of single phase cubic mixed spinel structure. Cation distribution has been proposed from Rietveld refined data. Mössbauer spectra at room temperature showed two ferrimagnetic Zeeman sextets with one superparamagnetic doublet. Mössbauer parameters suggested that Gd3+ ions occupy the octahedral site in CoFe2O4. Room temperature magnetic measurements exhibited that the saturation magnetization decreased from 91 emu/gm to 54 emu/gm for x=0.0 to 0.15 samples. The coercivity decreased from 1120 Oe to 340 Oe for x=0.0 to 0.07 samples and increased from 400 Oe to 590 Oe for x=0.10 and 0.15 samples, respectively. Raman analysis showed that the degree of inversion with Gd3+ substitution supporting the variation of coercivity. Electron spin resonance spectra revealed the dominancy of superexchange interactions in these samples. Optical band gap measurement suggested that all samples are indirect band gap materials and band gap has been decreased with Gd3+ substitution. Both dielectric constant and dielectric loss is found to decrease because of the decrease in hopping rate with the Gd3+ substitution for Fe3+ at the octahedral sites. Low dielectric loss suggested the applicability of Gd3+ doped CoFe2O4 nanoparticles for high frequency microwave device applications.

  2. The effect of a crosslinking chemical reaction on pattern formation in viscous fingering of miscible fluids in a Hele-Shaw cell

    Science.gov (United States)

    Bunton, Patrick H.; Tullier, Michael P.; Meiburg, Eckart; Pojman, John A.

    2017-10-01

    Viscous fingering can occur in fluid motion whenever a high mobility fluid displaces a low mobility fluid in a Darcy type flow. When the mobility difference is primarily attributable to viscosity (e.g., flow between the two horizontal plates of a Hele-Shaw cell), viscous fingering (VF) occurs, which is sometimes termed the Saffman-Taylor instability. Alternatively, in the presence of differences in density in a gravity field, buoyancy-driven convection can occur. These instabilities have been studied for decades, in part because of their many applications in pollutant dispersal, ocean currents, enhanced petroleum recovery, and so on. More recent interest has emerged regarding the effects of chemical reactions on fingering instabilities. As chemical reactions change the key flow parameters (densities, viscosities, and concentrations), they may have either a destabilizing or stabilizing effect on the flow. Hence, new flow patterns can emerge; moreover, one can then hope to gain some control over flow instabilities through reaction rates, flow rates, and reaction products. We report effects of chemical reactions on VF in a Hele-Shaw cell for a reactive step-growth cross-linking polymerization system. The cross-linked reaction product results in a non-monotonic viscosity profile at the interface, which affects flow stability. Furthermore, three-dimensional internal flows influence the long-term pattern that results.

  3. Synthesis and antimicrobial activity of some new substituted 9-(1H-Pyrazolo [3, 4-b] Quinolin-1-YL) Acridines

    International Nuclear Information System (INIS)

    Thakor, S.; Parmar, P.; Patel, M.; Patel, R.

    2008-01-01

    2-chloro-6-methyl/methoxy-3-formylquinoline upon condensation with substituted 9-hydrazino-acridine afforded corresponding hydrazones which were cyclized under alkaline condition to give 9-(6-substituted-1H-pyrazolo [3, 4-b] quinolin-1-yl) acridine analoges. All of the synthesized compounds were characterized by their elemental analysis, IR and NMR spectral studies. Biological screenings of the prepared compounds have been screened on some strain of bacteria and fungus. (author)

  4. Basicity comparison for di-substituted 4-nitropyridine derivatives in polar non-aqueous media

    International Nuclear Information System (INIS)

    Gurzynski, Lukasz; Puszko, Aniela; Chmurzynski, Lech

    2007-01-01

    Acid dissociation, as well as cationic homoconjugation equilibria have been studied potentiometrically in systems involving four di-substituted 4-nitropyridines and conjugate cationic acids in the polar non-aqueous solvents - aprotic protophobic acetonitrile (AN) and propylene carbonate (PC), the amphiprotic methanol (MeOH), and in the aprotic protophilic dimethyl sulfoxide (DMSO). The influence of solvent effect on the obtained acidity constants has been discussed. The acidity constants (expressed as pK a values) were compared with those previously determined in another polar protophobic aprotic solvent - acetone (AC), and obtained for the unsubstituted pyridine (Py). A comparison of the acid dissociation constants determined in all media studied has proved that the strength of the cationic acids increases on going from acetonitrile through propylene carbonate, acetone, and methanol to dimethyl sulfoxide. Furthermore, the values of acidity constants in the non-aqueous media have shown that in all the solvents studied they change according to the substituent effects. It has been also found that substituted 4-nitropyridine derivatives studied exhibit no tendency towards cationic homoconjugation in acetonitrile, propylene carbonate, and methanol and dimethyl sulfoxide. Moreover, it has been demonstrated that the acid dissociation constants determined by potentiometric titration method in all the solutions investigated correlate well with the calculated energy parameters of the protonation reactions in the gaseous phase

  5. Basicity comparison for di-substituted 4-nitropyridine derivatives in polar non-aqueous media

    Energy Technology Data Exchange (ETDEWEB)

    Gurzynski, Lukasz [Department of General and Inorganic Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk (Poland); Puszko, Aniela [Department of Organic Chemistry, School of Economics, Wroclaw (Poland); Chmurzynski, Lech [Department of General and Inorganic Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk (Poland)], E-mail: lech@chemik.chem.univ.gda.pl

    2007-12-15

    Acid dissociation, as well as cationic homoconjugation equilibria have been studied potentiometrically in systems involving four di-substituted 4-nitropyridines and conjugate cationic acids in the polar non-aqueous solvents - aprotic protophobic acetonitrile (AN) and propylene carbonate (PC), the amphiprotic methanol (MeOH), and in the aprotic protophilic dimethyl sulfoxide (DMSO). The influence of solvent effect on the obtained acidity constants has been discussed. The acidity constants (expressed as pK{sub a} values) were compared with those previously determined in another polar protophobic aprotic solvent - acetone (AC), and obtained for the unsubstituted pyridine (Py). A comparison of the acid dissociation constants determined in all media studied has proved that the strength of the cationic acids increases on going from acetonitrile through propylene carbonate, acetone, and methanol to dimethyl sulfoxide. Furthermore, the values of acidity constants in the non-aqueous media have shown that in all the solvents studied they change according to the substituent effects. It has been also found that substituted 4-nitropyridine derivatives studied exhibit no tendency towards cationic homoconjugation in acetonitrile, propylene carbonate, and methanol and dimethyl sulfoxide. Moreover, it has been demonstrated that the acid dissociation constants determined by potentiometric titration method in all the solutions investigated correlate well with the calculated energy parameters of the protonation reactions in the gaseous phase.

  6. Three inorganic-organic hybrids of bismuth(III) iodide complexes containing substituted 1,2,4-triazole organic components with charaterizations of diffuse reflectance spectra

    International Nuclear Information System (INIS)

    Liu Bing; Xu Ling; Guo Guocong; Huang Jinshun

    2006-01-01

    The reactions of two kinds of substituted 1,2,4-triazoles with BiI 3 yielded three inorganic-organic hybrids: [HL1] 4 [Bi 6 I 22 ].[L1] 4 .4H 2 O (1) (L1=3-(1,2,4-triazole-4-yl)-1H-1,2,4-triazole); [HL2] 4 [Bi 6 I 22 ].6H 2 O (2); [HL2] 2 [Bi 2 I 8 ].[L2] 2 (3) (L2=(m-phenol)-1,2,4-triazole). Both 1 and 2 have polynuclear anions of [Bi 6 I 22 ] 4- to build up the inorganic layers and substituted 1,2,4-triazoles as the organic layers. Hybrid 3 consists of two BiI 5 square pyramids as inorganic layers. There exist hydrogen bondings and I...;I interactions in the structures of 1, 2 and 3. Optical absorption spectra of 1, 2 and 3 reveal the presence of sharp optical gaps of 1.77, 1.77 and 2.07 eV, respectively, suggesting that these materials behave as semiconductors. - Graphical abstract: The reactions of two kinds of the substituted 1,2,4-triazoles with BiI 3 yielded three layered inorganic-organic hybrids [HL1] 4 [Bi 6 I 22 ].[L1] 4 .4H 2 O (1), [HL2] 4 [Bi 6 I 22 ].6H 2 O (2), [HL2] 2 [Bi 2 I 8 ].[L2] 2 (3) with optical gaps of 1.77, 1.77 and 2.07 eV, respectively. The structures of 1-3 are constructed from inorganic layers of polynuclear anions of bismuth iodine and organic layers of the substituted 1,2,4-triazoles

  7. Candida antartica lipase-catalyzed hydrolysis of 4-substituted bis(ethoxycarbonylmethyl) 1,4-dihydropyridine-3,5-dicarboxylates as the key step in the synthesis of optically active dihydropyridines

    NARCIS (Netherlands)

    Sobolev, A.; Franssen, M.C.R.; Makarova, N.; Duburs, G.; Groot, de Æ.

    2001-01-01

    Prochiral bis(ethoxycarbonylmethyl) substituted 4-aryl-1,4-dihydropyridine-3,5-dicarboxylates were hydrolyzed enantioselectively by Candida antarctica lipase B (Novozym 435). The enantiomeric excesses varied from 68 to 93°depending on the substituent at position 4. In some cases, the e.e. could be

  8. Formation, spectroscopic characterization, and solution stability of an [Fe4S4]2+ cluster derived from β-cyclodextrin dithiolate.

    Science.gov (United States)

    Lo, Wayne; Zhang, Ping; Ling, Chang-Chun; Huang, Shaw; Holm, R H

    2012-09-17

    The formation and solution properties, including stability in mixed aqueous-Me(2)SO media, have been investigated for an [Fe(4)S(4)](2+) cluster derived from β-cyclodextrin (CD) dithiolate. Clusters of the type [Fe(4)S(4)(SAr)(4)](2-) (Ar = Ph, C(6)H(4)-3-F) are generated in Me(2)SO by redox reactions of [Fe(4)S(4)(SEt)(4)](2-) with 2 equiv of ArSSAr. An analogous reaction with the intramolecular disulfide of 6(A),6(D)-(3-NHCOC(6)H(4)-1-SH)(2)-6(A),6(D)-dideoxy-β-cyclodextrin (14), whose synthesis is described, affords a completely substituted cluster formulated as [Fe(4)S(4){β-CD-(1,3-NHCOC(6)H(4)S)(2)}(2)](2-) (15). Ligand binding is indicated by a circular dichroism spectrum and also by UV-visible and isotropically shifted (1)H NMR spectra and redox behavior convincingly similar to [Fe(4)S(4)(SPh)(4)](2-). One formulation of 15 is a single cluster to which two dithiolates are bound, each in bidentate coordination. With there being no proven precedent for this binding mode, we show that the cluster [Fe(4)S(4)(S(2)-m-xyl)(2)](2-) is a single cubane whose m-xylyldithiolate ligands are bound in a bidentate arrangement. This same structure type was proposed for a cluster formulated as [Fe(4)S(4){β-CD-(1,3-SC(6)H(4)S)(2)}(2)](2-) (16; Kuroda et al. J. Am. Chem. Soc.1988, 110, 4049-4050) and reported to be water-stable. Clusters 15 and 16 are derived from similar ligands differing only in the spacer group between the thiolate binding site and the CD platform. In our search for clusters stable in aqueous or organic-aqueous mixed solvents that are potential candidates for the reconstitution of scaffold proteins implicated in cluster biogenesis, 15 is the most stable cluster that we have thus far encountered under anaerobic conditions in the absence of added ligand.

  9. On the synthesis, characterization, rationalization of the structure and the compositional formula of Ti-substituted Li0,5Fe2,5O4

    International Nuclear Information System (INIS)

    Widatallah, H.M.; Berry, F.J.; Moore, E.A.; Johnson, C.; Jartych, E.; Pekala, M.; Grabski, J.

    2002-12-01

    Spinel-related titanium-substituted Li 0.5 Fe 2.5 O 4 has been synthesised by heating a mixture of titanium-doped corundum-related α-Fe 2 O 3 with Li 2 CO 3 at 850 deg C which is ca. 250-350 deg C lower than temperatures at which the material is normally prepared conventionally. Moessbauer and magnetic measurements imply that the Ti 4+ ions substitute for octahedral Fe 3+ ions. Interatomic potential calculations support this substitution with the charge balance being maintained by Li + vacancies. This structural model leads to a compositional formula of the type Li (0.5-x) + Ti x 4+ Fe (2.5-x) 3+ O 4 which is shown to be more appropriate than the one generally used in the literature, namely Li (0.5+0.5x) + Ti x 4+ Fe (2.5-1.5x) 3+ O 4 . Some implications of the suggested formula are discussed including the possibility of the existence of a thermodynamically stable titanium ferrite of the form Ti 0.5 Fe 2 O 4 . (author)

  10. Zn substitution NiFe_2O_4 nanoparticles with enhanced conductivity as high-performances electrodes for lithium ion batteries

    International Nuclear Information System (INIS)

    Mao, Junwei; Hou, Xianhua; Huang, Fengsi; Shen, Kaixiang; Lam, Kwok-ho; Ru, Qiang; Hu, Shejun

    2016-01-01

    Zn"2"+ ion substituted nickel ferrite nanomaterials with the chemical formula Ni_1_−_xZn_xFe_2O_4 for x = 0, 0.3, 0.5, 0.7 and 1 have been synthesized by a facile green-chemical hydrothermal method as anode materials in lithium ion battery. The morphology and structure of the samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The physical and electrochemical properties were tested by electrochemical system. Furthermore, the energetic and electronic properties of the samples were investigated by density functional calculations. The results suggest that Zn substitution can affect the conduction performance of the zinc - nickel ferrite. Meanwhile, electrochemical results show that an enhancement in the capacity with increasing Zn concentration is observed especially for x = 0.3 which exhibit high discharge capacity of 1416 mAh g"−"1at the end of 100th cycle. Moreover, the theoretical research method with high yield synthesis strategy described in the present work holds promise for the general fabrication of other metallic elements substitution in complex transition metal oxides for high power LIBs. - Highlights: • Ni_1_−_xZn_xFe_2O_4 anodes have been synthesized by hydrothermal method. • First principles calculation was used to investigate the conduction performance. • Electrochemical performance was enhanced with Zn substitution.

  11. Design and synthesis of new potent PTP1B inhibitors with the skeleton of 2-substituted imino-3-substituted-5-heteroarylidene-1,3-thiazolidine-4-one: Part I.

    Science.gov (United States)

    Meng, Ge; Zheng, Meilin; Wang, Mei; Tong, Jing; Ge, Weijuan; Zhang, Jiehe; Zheng, Aqun; Li, Jingya; Gao, Lixin; Li, Jia

    2016-10-21

    A new series of 2-substituted imino-3-substituted-5- heteroarylidene-1,3-thiazolidine-4-ones as the potent bidentate PTP1B inhibitors were designed and synthesized in this paper. All of the new compounds were characterized and identified by spectra analysis. The biological screening test against PTP1B showed that some of these compounds have the positive inhibitory activity against PTP1B. The activity of the compounds with 5-substituted pyrrole on 5-postion of 1,3-thiazolidine-4-one are more potent than that of those compounds with 5-substituted pyridine group. Compound 14b, 14h and 14i showed IC50 values of 8.66 μM, 6.83 μM and 6.09 μM against PTP1B, respectively. Docking analysis of these active compounds with PTP1B showed the possible interaction modes of these biheterocyclic compounds with the active sites of PTP1B. The inhibition tests against oncogenetic CDC25B were also conducted on this set of compounds to evaluate the selectivity and possible anti-neoplastic activity. Compound 14b also showed the lowest IC50 of 1.66 μM against CDC25B among all the possible inhibitors, including 14g, 14h, 14i and 15c. Some pharmacological parameters including VolSurf, steric and electric descriptors of all the compounds were calculated to give some hints about the relative relationship with the biological activity. The result of this study might give some light on designing the possible anti-cancer drugs targeting at phosphatases. The most active compound 14i might be used as the lead compound for further structure modification of the new low molecular weight PTP1B inhibitors with the N-containing heterocyclic skeleton. Copyright © 2016. Published by Elsevier Masson SAS.

  12. Microwave Assisted Synthesis of 2,2'-Arylene-substituted Bis(4H-3,1-Benzoxazin-4-one Derivatives Using the Complex Cyanuric Chloride/N,N-Dimethylformamide

    Directory of Open Access Journals (Sweden)

    Mehdi Shariat

    2012-09-01

    Full Text Available A new and efficient method has been designed to prepare 2,2'-arylene-substituted bis(4H-3,1-benzoxazin-4-one derivatives by using the mixture of cyanuric chloride and N,N-dimethylformamide in a microwave-assisted reaction. The method used and presented here has good rate enhancement and excellent yields.

  13. Pressure effect on magnetic and transport properties of FeCr{sub 2}S{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Y.M. [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002 (China); Tong, R. [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031 (China); Yang, Z.R., E-mail: zryang@issp.ac.cn [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031 (China)

    2016-10-15

    In this paper, the influence of chemical pressure caused by Se substituting and hydrostatic pressure on magnetic and transport properties of FeCr{sub 2}S{sub 4} have been investigated. In addition to a large irreversibility between zero-field-cooled (ZFC) and field-cooled (FC) magnetization under low magnetic field, FeCr{sub 2}S{sub 4} polycrystalline sample also shows a cusp-like anomaly around 70 K and a step-like transition around 9 K. With increasing Se content, ferrimagnetic transition temperature decreases, irreversibility between ZFC and FC magnetization increases. At the same time, both the step-like transition and the cusp-like anomaly in magnetization shift to a lower temperature and disappears gradually. All the above effects caused by Se substituting are in accord with the effects caused by applying hydrostatic pressure. Furthermore, we found magnetoresistance increases with increasing Se content, and attributed it to the stabilization of magnetic polarons. - Highlights: • Se doping makes the anomalies in magnetization shift toward lower temperatures. • Chemical pressure effects are in accord with hydrostatic pressure effects. • Magnetoresistance increases with increasing Se content.

  14. Voltammetric oxidation of Hantzsch 1,4-dihydropyridines in protic and aprotic media: relevance of the substitution on N position

    International Nuclear Information System (INIS)

    Lopez-Alarcon, C.; Nunez-Vergara, L.J.; Squella, J.A.

    2003-01-01

    A detailed investigation on the electrochemical oxidation of some Hantzsch 1,4-dihydropyridine derivatives with the aim of study the influence of the hydrogen substituent on the N1 position of the heterocyclic ring have been carried out in protic and aprotic media. For this objective we have synthesized two series of compounds wherein the difference was the substituent (H or ethyl) on the N1-position of the heterocyclic ring. Voltammetry, UV-Vis spectroscopy, Controlled potential electrolysis, EPR, 1 H NMR and gas chromatography-mass spectrometry techniques in order to obtain evidences for postulate oxidation mechanisms in both protic and aprotic media have been used. Compounds having the ethyl substituent in the N1 position follow an oxidation mechanism obeying the sequence ECE with the second step as the r.d.e. in both, protic and aprotic media, thus producing the corresponding ethyl substituted pyridinium cation. On the other hand compounds having H in the N1 position follow the same ECE sequence only at acidic media. At basic media, the mechanism consisted of a DISP1 scheme in which rate determining step (r.d.s.) is the uptake of the proton in the N1 position by the OH - ion of the media. In aprotic media both type of compounds follow the same ECEC mechanism with the second step as the r.d.s. but only the H-substituted compounds generates an anionic species that is more easily oxidized than the parent compounds

  15. Rayleigh-Benard convection in a Hele-Shaw cell - a numerical study

    International Nuclear Information System (INIS)

    Guenther, C.; Mueller, U.

    1987-05-01

    Free convection in narrow vertical gaps heated from below gives rise to several different flow patterns as has been demonstrated by previous experimental investigations. A numerical study is presented aimed at simulating the observed flow phenomena in Hele-Shaw cells of small lateral extend. The numerical study is based on the assumption that the flow is essentially two-dimensional. This allows an approach using a one-term Galerkin approximation with respect to the direction perpendicular to the gap and a finite difference scheme with regard to the coordinates in the plane of the gap. The calculations result in realistic values of the critical Rayleigh numbers for the onset of steady and oscillatory convection. Most of the observed unsteady flow patterns can be simulated numerically. It is shown that five different stable flow patterns can occur at one particular Rayleigh number. The different stable flow patterns are coupled by a variety of complex transitions. Moreover the calculations show that a realistic description of the observed flow phenomena can not be obtained by a simplified model using the Darcy law in the momentum equation and implying slip flow at the small confining boundaries. (orig.) [de

  16. Effect of Gd"3"+ substitution on structural, magnetic, dielectric and optical properties of nanocrystalline CoFe_2O_4

    International Nuclear Information System (INIS)

    Joshi, Seema; Kumar, Manoj; Chhoker, Sandeep; Kumar, Arun; Singh, Mahavir

    2017-01-01

    Nanoparticles of CoGd_xFe_2_−_xO_4 with x=0.0, 0.03, 0.05, 0.07, 0.10 and 0.15 were synthesized by co-precipitation method. Gd"3"+ substitution effect on different properties of nanocrystalline CoFe_2O_4 has been studied. X-ray diffraction and Raman spectroscopy confirmed the formation of single phase cubic mixed spinel structure. Cation distribution has been proposed from Rietveld refined data. Mössbauer spectra at room temperature showed two ferrimagnetic Zeeman sextets with one superparamagnetic doublet. Mössbauer parameters suggested that Gd"3"+ ions occupy the octahedral site in CoFe_2O_4. Room temperature magnetic measurements exhibited that the saturation magnetization decreased from 91 emu/gm to 54 emu/gm for x=0.0 to 0.15 samples. The coercivity decreased from 1120 Oe to 340 Oe for x=0.0 to 0.07 samples and increased from 400 Oe to 590 Oe for x=0.10 and 0.15 samples, respectively. Raman analysis showed that the degree of inversion with Gd"3"+ substitution supporting the variation of coercivity. Electron spin resonance spectra revealed the dominancy of superexchange interactions in these samples. Optical band gap measurement suggested that all samples are indirect band gap materials and band gap has been decreased with Gd"3"+ substitution. Both dielectric constant and dielectric loss is found to decrease because of the decrease in hopping rate with the Gd"3"+ substitution for Fe"3"+ at the octahedral sites. Low dielectric loss suggested the applicability of Gd"3"+ doped CoFe_2O_4 nanoparticles for high frequency microwave device applications. - Highlights: • Gd"3"+ ions were successfully added in to the spinel lattice of CoFe_2O_4. • Magnetic hysteresis loss is influenced by Gd"3"+ doping. • All doped samples exhibit normal dielectric dispersion behaviour of spinel ferrites. • UV–vis diffuse spectroscopy concludes band gap is reduced by Gd"3"+ doping.

  17. Lack of energy compensation over 4 days when white button mushrooms are substituted for beef.

    Science.gov (United States)

    Cheskin, Lawrence J; Davis, Lisa M; Lipsky, Leah M; Mitola, Andrea H; Lycan, Thomas; Mitchell, Vanessa; Mickle, Brooke; Adkins, Emily

    2008-07-01

    Increasing intake of low energy density (ED) foods in place of high ED foods has been proposed as a strategy for preventing or treating obesity. This study investigated how substituting mushrooms for beef in a test lunch affected energy intake, fat intake, palatability, appetite, satiation and satiety in normal weight, overweight and obese adults. Each subject consumed a total of eight test lunches in our lab over two consecutive weeks. The order of presentation of four consecutive meat lunches and four consecutive mushroom lunches was randomized. Energy content of meat and mushroom lunches varied (783 kcal versus 339 kcal), while volume was held constant. Energy intakes were significantly higher during meat lunches than mushroom lunches (730+/-7.9 kcal versus 310+/-5.8 kcal). Subjects exhibited only partial compensation (11.4+/-12.0%) for this difference over 4 days. Total daily energy intake and fat intake were significantly greater in the meat condition than in the mushroom condition, while ratings of palatability, appetite, satiation and satiety did not differ significantly. These results suggest that substituting low ED foods for high ED foods in otherwise similar recipes can be an effective method for reducing daily energy and fat intake.

  18. Site selective substitution Pt for Ti in KTiOPO{sub 4}:Ga crystals revealed by electron paramagnetic resonance

    Energy Technology Data Exchange (ETDEWEB)

    Grachev, V.; Meyer, M.; Jorgensen, J.; Malovichko, G. [Department of Physics, Montana State University, Bozeman, Montana 59717 (United States); Hunt, A. W. [Idaho Accelerator Center, Idaho State University, Pocatello, Idaho 83209 (United States)

    2014-07-28

    Electron Paramagnetic Resonance at low temperatures has been used to characterize potassium titanyl phosphate (KTiOPO{sub 4}) single crystals grown by different techniques. Irradiation with 20 MeV electrons performed at room temperature and liquid nitrogen temperature caused an appearance of electrons and holes. Platinum impurities act as electron traps in KTiOPO{sub 4} creating Pt{sup 3+} centers. Two different Pt{sup 3+} centers were observed, Pt(A) and Pt(D). The Pt(A) centers are dominant in undoped samples, whereas Pt(D)—in Ga-doped KTP crystals. Superhyperfine structure registered for Pt(D) centers was attributed to interactions of platinum electrons with {sup 39}K and two {sup 31}P nuclei in their surroundings. In both Pt(A) and Pt(D) centers, Pt{sup 3+} ions substitute for Ti{sup 4+} ions, but with a preference to one of two electrically distinct crystallographic positions. The site selective substitution can be controlled by the Ga-doping.

  19. Cfr and RlmN contain a single [4Fe-4S] cluster, which directs two distinct reactivities for S-adenosylmethionine: methyl transfer by SN2 displacement and radical generation.

    Science.gov (United States)

    Grove, Tyler L; Radle, Matthew I; Krebs, Carsten; Booker, Squire J

    2011-12-14

    The radical SAM (RS) proteins RlmN and Cfr catalyze methylation of carbons 2 and 8, respectively, of adenosine 2503 in 23S rRNA. Both reactions are similar in scope, entailing the synthesis of a methyl group partially derived from S-adenosylmethionine (SAM) onto electrophilic sp(2)-hybridized carbon atoms via the intermediacy of a protein S-methylcysteinyl (mCys) residue. Both proteins contain five conserved Cys residues, each required for turnover. Three cysteines lie in a canonical RS CxxxCxxC motif and coordinate a [4Fe-4S]-cluster cofactor; the remaining two are at opposite ends of the polypeptide. Here we show that each protein contains only the one "radical SAM" [4Fe-4S] cluster and the two remaining conserved cysteines do not coordinate additional iron-containing species. In addition, we show that, while wild-type RlmN bears the C355 mCys residue in its as-isolated state, RlmN that is either engineered to lack the [4Fe-4S] cluster by substitution of the coordinating cysteines or isolated from Escherichia coli cultured under iron-limiting conditions does not bear a C355 mCys residue. Reconstitution of the [4Fe-4S] cluster on wild-type apo RlmN followed by addition of SAM results in rapid production of S-adenosylhomocysteine (SAH) and the mCys residue, while treatment of apo RlmN with SAM affords no observable reaction. These results indicate that in Cfr and RlmN, SAM bound to the unique iron of the [4Fe-4S] cluster displays two reactivities. It serves to methylate C355 of RlmN (C338 of Cfr), or to generate the 5'-deoxyadenosyl 5'-radical, required for substrate-dependent methyl synthase activity. © 2011 American Chemical Society

  20. Synthesis of 3-substituted 4-piperidinones via a one-pot tandem oxidation-cyclization-oxidation process: stereodivergent reduction to 3,4-disubstituted piperidines.

    Science.gov (United States)

    Bahia, Perdip S; Snaith, John S

    2004-04-30

    A novel approach to 3-substituted 4-piperidinones is described. The one-pot tandem oxidation-cyclization-oxidation of unsaturated alcohols 1a-e by PCC or PCC and trifluoromethanesulfonic acid affords piperidinones 2a-e in good yield. Reduction of 2a-e by L-Selectride gives the corresponding cis 3,4-disubstituted piperidines with diastereomeric ratios of >99:1. By contrast, reduction of 2a-e by Al-isopropoxydiisobutylalane gives the trans products with diastereomeric ratios of up to 99:1.

  1. Synthesis of Novel Benzimidazolyl-substituted Acrylonitriles and Amidino-substituted Benzimidazo[1,2-a]Quinolines

    Directory of Open Access Journals (Sweden)

    Grace Karminski-Zamola

    2006-08-01

    Full Text Available A series of novel benzimidazole derivatives 3-10 were synthesized. Benzimidazolyl-substituted acrylonitriles 3 and 4 underwent a photochemical dehydrocyclization reaction to give the corresponding mono- and dicyano-substituted benzimidazo[1,2-a] quinolines 5 and 6. Pinner reaction of these compounds did not give the expected mono- and diamidines, but rather only compounds 7-10, with amido groups at 6-position were isolated. A mechanism for the reaction is proposed. Acyclic compounds 3 and 4, as well as cyclic benzimidazo[1,2-a]quinolines 5-8, exhibit interesting spectroscopic properties and are potential biologically active compounds.

  2. Substitution effect and effect of axle’s flexibility at (pseudo-rotaxanes

    Directory of Open Access Journals (Sweden)

    Friedrich Malberg

    2014-06-01

    Full Text Available This study investigates the effect of substitution with different functional groups and of molecular flexibility by changing within the axle from a single C–C bond to a double C=C bond. Therefore, we present static quantum chemical calculations at the dispersion-corrected density functional level (DFT-D3 for several Leigh-type rotaxanes. The calculated crystal structure is in close agreement with the experimental X-ray data. Compared to a stiffer axle, a more flexible one results in a stronger binding by 1–3 kcal/mol. Alterations of the binding energy in the range of 5 kcal/mol could be achieved by substitution with different functional groups. The hydrogen bond geometry between the isophtalic unit and the carbonyl oxygen atoms of the axle exhibited distances in the range of 2.1 to 2.4 Å for six contact points, which shows that not solely but to a large amount the circumstances in the investigated rotaxanes are governed by hydrogen bonding. Moreover, the complex with the more flexible axle is usually more unsymmetrical than the one with the stiff axle. The opposite is observed for the experimentally investigated axle with the four phenyl stoppers. Furthermore, we considered an implicit continuum solvation model and found that the complex binding is weakened by approximately 10 kcal/mol, and hydrogen bonds are slightly shortened (by up to 0.2 Å.

  3. Interfuel substitution in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Serletis, Apostolos; Vasetsky, Olexandr [Department of Economics, University of Calgary, Calgary, Alberta (Canada); Timilsina, Govinda R. [Development Research Group, The World Bank, 1818 H Street N.W., Washington, DC 20433 (United States)

    2010-05-15

    In this paper, we use the locally flexible translog functional form to investigate the demand for energy and interfuel substitution in the United States and to provide a comparison of our results with most of the existing empirical energy demand literature. Motivated by the widespread practice of ignoring theoretical regularity, we follow Barnett's (2002) suggestions and estimate the model subject to theoretical regularity, using methods developed by Diewert and Wales (1987) and Ryan and Wales (2000), in an attempt to produce inference consistent with neoclassical microeconomic theory. Moreover, we use the most recent data, published by the U.S. Energy Information Administration (EIA), and in addition to investigating interfuel substitution possibilities in total U.S. energy demand, we follow Serletis et al. (2009) and also examine interfuel substitution possibilities in energy demand by sector. Moreover, we test for weak separability, with the objective of discovering the structure of the functional form in total energy demand as well as energy demand by sector. (author)

  4. Solvent substitution

    International Nuclear Information System (INIS)

    1990-01-01

    The DOE Environmental Restoration and Waste Management Office of Technology Development and the Air Force Engineering and Services Center convened the First Annual International Workshop on Solvent Substitution on December 4--7, 1990. The primary objectives of this joint effort were to share information and ideas among attendees in order to enhance the development and implementation of required new technologies for the elimination of pollutants associated with industrial use of hazardous and toxic solvents; and to aid in accelerating collaborative efforts and technology transfer between government and industry for solvent substitution. There were workshop sessions focusing on Alternative Technologies, Alternative Solvents, Recovery/Recycling, Low VOC Materials and Treatment for Environmentally Safe Disposal. The 35 invited papers presented covered a wide range of solvent substitution activities including: hardware and weapons production and maintenance, paint stripping, coating applications, printed circuit boards, metal cleaning, metal finishing, manufacturing, compliance monitoring and process control monitoring. This publication includes the majority of these presentations. In addition, in order to further facilitate information exchange and technology transfer, the US Air Force and DOE solicited additional papers under a general ''Call for Papers.'' These papers, which underwent review and final selection by a peer review committee, are also included in this combined Proceedings/Compendium. For those involved in handling, using or managing hazardous and toxic solvents, this document should prove to be a valuable resource, providing the most up-to-date information on current technologies and practices in solvent substitution. Individual papers are abstracted separated

  5. Structural and magnetic properties of Co substituted Li{sub 0.5}Fe{sub 2.5}O{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Patil, R.P., E-mail: raj_rbm_raj@yahoo.co.in [Department of Chemistry, M.H. Shinde Mahavidyalaya, Tisangi 416206, MH (India); Patil, S.B. [Department of Physics, Krantisinh Nana Patil College Walwa, Sangli 416313, MH (India); Jadhav, B.V. [Department of Chemistry, Changu Kana Thakur Arts, Commerce and Science College, New Panvel 400035, MH (India); Delekar, S.D.; Hankare, P.P. [Department of Chemistry, Shivaji University, Kolhapur 416004, MH (India)

    2016-03-01

    Nanocrystalline Li{sub 0.5}Fe{sub 2.5−x}Co{sub x}O{sub 4} (2.5≥x≥0) system was prepared by sol–gel route. Formation of single phase cubic spinel structure for all the compositions was confirmed from their X-ray diffraction studies. These ferrite samples existed as homogenous and uniform grains as observed from Scanning Electron Microscopy technique. The magnetic studies indicated that, the ferrimagnetic behavior decreases with Cobalt substitution. In general, the substitution of cobalt plays an important role in changing the structural and magnetic properties of these ferrites. - Highlights: • Novel Co doped Li{sub 0.5}Fe{sub 2.5}O{sub 4} system. • Sol–gel method synthesized Co–Lithium ferrites. • Single Phase Cubic spinel structure. • Homogenous and uniform grain size of samples. • Ferrimagnetic behavior for all the samples.

  6. Substitution and Redox Chemistry of [Bu(4)N](2)[Ta(6)Cl(12)(OSO(2)CF(3))(6)].

    Science.gov (United States)

    Prokopuk, Nicholas; Kennedy, Vance O.; Stern, Charlotte L.; Shriver, Duward F.

    1998-09-21

    Two sequential electrochemical reductions occur for the cluster anion [Ta(6)Cl(12)(OSO(2)CF(3))(6)](2)(-) at 0.89 and 0.29 V vs Ag/AgCl, with the generation [Ta(6)Cl(12)(OSO(2)CF(3))(6)](3)(-) and [Ta(6)Cl(12)(OSO(2)CF(3))(6)](4)(-). Chemical reduction of [Ta(6)Cl(12)(OSO(2)CF(3))(6)](2)(-) by ferrocene produces [Ta(6)Cl(12)(OSO(2)CF(3))(6)](3)(-) with the concomitant shift of the nu(SO(2)) stretch from 1002 to 1018 cm(-)(1). Reaction of [Bu(4)N](2)[Ta(6)Cl(12)(OSO(2)CF(3))(6)] (1) with [Bu(4)N]X (X = Cl, Br, I, NCS) occurs by reduction and substitution, yielding [Bu(4)N](3)[Ta(6)Cl(12)X(6)], where the clusters with X = Br, I, and NCS are new. Spectroscopic (IR and UV-vis) evidence indicates that the reduced cluster core {Ta(6)Cl(12)}(2+) is produced in reaction mixtures of 1 with the halide and pseudohalide ions. Concomitant substitution of the triflate ligands of 1 by X(-) occurs and the rates for the overall reduction and substitution increase in the order X(-) = Cl(-) < Br(-) < NCS(-) < I(-) < CN(-). Reduction of 1 with ferrocene followed by addition of [Bu(4)N]O(2)CCH(3) produces the new cluster [Ta(6)Cl(12)(O(2)CCH(3))(6)](3)(-) isolated as the tetrabutylammonium salt. Cyclic voltammetry and UV-vis spectroscopy on the new clusters [Bu(4)N](3)[Ta(6)Cl(12)X(6)] (X = Br, I, NCS, and O(2)CCH(3)) are reported. Crystal data for [Bu(4)N](3)[Ta(6)Cl(12)(NCS)(6)].CH(2)Cl(2): monoclinic, space group, P2(1)/c (No. 14); a = 25.855(6) Å, b = 21.843(6) Å, c = 16.423(3) Å; beta = 100.03(2) degrees; V = 9133(3) Å(3); Z = 4.

  7. Photochemical reaction of Si-substituted ethynylsilanes with 1,2-ethanedithiol

    Energy Technology Data Exchange (ETDEWEB)

    Voronkov, M.G.; Brodskaya, E.I.; Kalabin, G.A.; Vlasova, N.N.; Yarosh, O.G.; Zhila, G.Y.

    1985-12-01

    The authors investigate the chief products of the photochemical reactions of Si-substituted ethynylsilanes with 1,2,-ethanedithiol at 60-70 C. It is found that the chief products are 2-triorganylsilyl-substituted 1,4-dithiacyclopentanes and 1,4-dithiacyclohexanes. On lowering the temperature to -30 C, formation of bis (triorganylsilyl)-substituted 1,4,7,10-tetrathiacyclododecanes occurs along with the abo ve-mentioned five- and six-membered heterocycles.

  8. preparation and nucleophilic substitution of the 2,4,6

    African Journals Online (AJOL)

    Mgina

    Three methods for preparation of D-amino acids by nucleophilic substitution on derivatives of ... bioactivity of the peptide (Wenger 1985, ... Acetic acid (0.29 mL, 5 mmol) was added, and the mixture was further stirred for 5 h at rt under ... methanol/dichloromethane) to yield a white ... temperature, diluted with water, extracted.

  9. Hydrothermal synthesis and characterizations of Ti substituted Mn-ferrites

    Energy Technology Data Exchange (ETDEWEB)

    Mostafa, Nasser Y., E-mail: nmost69@yahoo.com [Faculty of Science, Taif University, P.O. Box 888 Al-Haweiah, Taif (Saudi Arabia); Chemistry Department, Faculty of Science, Suez Canal University, Ismailia 41522 (Egypt); Hessien, M.M. [Faculty of Science, Taif University, P.O. Box 888 Al-Haweiah, Taif (Saudi Arabia); Advanced materials Division-Central metallurgical R and D Institute (CMRDI), P.O. Box 87 Helwan, Cairo (Egypt); Shaltout, Abdallah A. [Faculty of Science, Taif University, P.O. Box 888 Al-Haweiah, Taif (Saudi Arabia); Spectroscopy Department, Physics Division, National Research Center, El Behooth Str., 12622 Dokki, Cairo (Egypt)

    2012-07-15

    Highlights: Black-Right-Pointing-Pointer Hydrothermal synthesized of well-crystallized Ti-substituted MnFe{sub 2}O{sub 4} nanoparticles at 180 Degree-Sign C without any calcination step. The chemical composition was represented by Mn{sub 1-2x}Ti{sub x}Fe{sub 2}O{sub 4} with x having values 0.0, 0.1, 0.2, 0.3 and 0.4. Black-Right-Pointing-Pointer The change in lattice parameter and saturation magnetization with increasing Ti-substitution was investigated and explained. Black-Right-Pointing-Pointer The change in microstructure due to Ti{sup 4+} ions substitutions was investigated using TEM analysis. - Abstarct: A series of well-crystallized Mn{sub 1-2x}Ti{sub x}Fe{sub 2}O{sub 4} nanoparticles with x values of 0.0, 0.1, 0.2, 0.3 and 0.4 have been synthesized by hydrothermal route at 180 Degree-Sign C in the presence of NaOH as mineralizer. The obtained ferrite samples were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM) and vibrating sample magnetometer (VSM). The XRD analysis showed that pure single phases of cubic ferrites were obtained with x up to 0.2. However, samples with x > 0.2 showed traces of unreacted anatase. The increase in Ti-substitution up to x = 0.2 leads to an increase in the lattice parameter of the prepared ferrites. On the other hand, the increase in Ti-substitution over x = 0.2 leads to a decrease in the lattice parameter. The average crystallite size was in the range of 39-57 nm, where it is increased by increasing the Ti-substitution up to x = 0.3, then decreased for x = 0.4. According to VSM results, the saturation magnetization increased with Ti ion substitution of x = 0.1 and decreased for x > 0.1.

  10. An improved synthesis of 2,2−-((4-substituted phenyl methylene difurans by Ultrasound irradiation

    Directory of Open Access Journals (Sweden)

    Naween M. Yonis

    2016-09-01

    Full Text Available A new series of 2,2−((4-substituted phenyl methylene difuran was synthesized by one-pot cyclocondensation of aldehyde with excess furan at room temperature using trifluoro acetic acid as a catalyst under ultrasound irradiation in the absence of solvent. The products were compared with the classical condensation reactions. This method consistently enjoys the advantages of mild reaction conditions, excellent yields, easy work up and short time.

  11. The substituted (S)-3-phenylpiperidine (-)-OSU6162 reduces apomorphine- and amphetamine-induced behaviour in Cebus apella monkeys

    DEFF Research Database (Denmark)

    Brandt-Christensen, Anne Mette; Andersen, M B; Fink-Jensen, A

    2006-01-01

    Low affinity dopamine (DA) D2 antagonists such as the substituted (S)-3-phenylpiperidine (-)-OSU6162 have been proposed to be putative antipsychotic agents not endowed with extrapyramidal side effects (EPS). In the present study we investigated the effects of (-)-OSU6162 on (-)-apomorphine and d-...

  12. Single Crystal Growth and Superconducting Properties of Antimony-Substituted NdO0.7F0.3BiS2

    Directory of Open Access Journals (Sweden)

    Satoshi Demura

    2017-12-01

    Full Text Available Antimony (Sb substitution of less than 8% was examined on a single crystal of a layered superconductor NdO0.7F0.3BiS2. The superconducting transition temperature of the substituted samples decreased as Sb concentration increased. A lattice constant along the c-axis showed a large decrease compared with that along the a-axis. Since in-plane chemical pressure monotonically decreased as Sb concentration increased, the suppression of the superconductivity is attributed to the decrease in the in-plane chemical pressure.

  13. DOES CURRENCY SUBSTITUTION AFFECT EXCHANGE RATE VOLATILITY?

    Directory of Open Access Journals (Sweden)

    Hisao Kumamoto

    2014-10-01

    Full Text Available This study investigates the impacts of the degree of currency substitution on nominal exchange rate volatility in seven countries (Indonesia, the Philippines, the Czech Republic, Hungary, Poland, Argentina, and Peru. We use the Threshold ARCH model to consider the ratchet effect of currency substitution and sample periods in the 2000s, during which time the economies of the sample countries stabilized, while the U.S. dollar and euro depreciated against other major currencies following the recent global financial crisis. The presented empirical analyses show that the degree of currency substitution has significant positive effects on the conditional variance of the depreciation rate of the nominal exchange rate in most sample countries. Moreover, a shock to the depreciation rate of the nominal exchange rate has asymmetric effects on the conditional variance, depending on the sign. One possible explanation for these differential effects is the existence of the ratchet effect of currency substitution.

  14. Structural, dielectric and gas sensing behavior of Mn substituted spinel MFe{sub 2}O{sub 4} (M=Zn, Cu, Ni, and Co) ferrite nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Ranjith Kumar, E., E-mail: ranjueaswar@gmail.com [Department of Physics, Dr. NGP Institute of Technology, Coimbatore 641048, Tamil Nadu (India); Siva Prasada Reddy, P.; Sarala Devi, G. [Inorganic and Physical Chemistry Division, Indian Institute Chemical Technology, Hyderabad 500607 (India); Sathiyaraj, S. [Department of Chemistry, Dr. NGP Institute of Technology, Coimbatore 641048, Tamil Nadu (India)

    2016-01-15

    Spinel ferrite (MnZnFe{sub 2}O{sub 4}, MnCuFe{sub 2}O{sub 4}, MnNiFe{sub 2}O{sub 4} and MnCoFe{sub 2}O{sub 4}) nanoparticles have been prepared by evaporation method. The annealing temperature plays an important role on changing particle size of the spinel ferrite nanoparticles was found out by X-ray diffraction and transmission electron microscopy. The role of manganese substitution in the spinel ferrite nanoparticles were also analyzed for different annealing temperature. The substitution of Mn also creates a vital change in dielectric properties have been measured in the frequency range of 100 kHz to 5 MHz. These spinel ferrites are decomposed to α-Fe{sub 2}O{sub 3} after annealing above 550 °C in air. Through the characterization of the prepared powder, the effect of annealing temperature, chemical composition and preparation technique on the microstructure, particle size and dielectric properties of the Mn substituted spinel ferrite nanoparticles are discussed. Furthermore, Conductance response of Mn substituted MFe{sub 2}O{sub 4} ferrite nanoparticles were measured by exposing the materials to reducing gas like liquefied petroleum gas (LPG). - Highlights: • The egg white support to achieve sample with shorter reaction time. • Manganese plays a significant role in sensor response. • Nature of the ferrites was affected with increasing annealing temperature.

  15. Synthesis of trifluoromethyl-substituted pyrazolo[4,3-c]pyridines – sequential versus multicomponent reaction approach

    Directory of Open Access Journals (Sweden)

    Barbara Palka

    2014-07-01

    Full Text Available A straightforward synthesis of 6-substituted 1-phenyl-3-trifluoromethyl-1H-pyrazolo[4,3-c]pyridines and the corresponding 5-oxides is presented. Hence, microwave-assisted treatment of 5-chloro-1-phenyl-3-trifluoromethylpyrazole-4-carbaldehyde with various terminal alkynes in the presence of tert-butylamine under Sonogashira-type cross-coupling conditions affords the former title compounds in a one-pot multicomponent procedure. Oximes derived from (intermediate 5-alkynyl-1-phenyl-3-trifluoromethyl-1H-pyrazole-4-carbaldehydes were transformed into the corresponding 1H-pyrazolo[4,3-c]pyridine 5-oxides by silver triflate-catalyzed cyclization. Detailed NMR spectroscopic investigations (1H, 13C, 15N and 19F were undertaken with all obtained products.

  16. 7-Phenoxy-Substituted 3,4-Dihydro-2H-1,2,4-benzothiadiazine 1,1-Dioxides as Positive Allosteric Modulators of α-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid (AMPA) Receptors with Nanomolar Potency

    DEFF Research Database (Denmark)

    Goffin, Eric; Drapier, Thomas; Larsen, Anja Probst

    2018-01-01

    We report here the synthesis of 7-phenoxy-substituted 3,4-dihydro-2H-1,2,4-benzothiadiazine 1,1-dioxides and their evaluation as AMPA receptor positive allosteric modulators (AMPApams). The impact of substitution on the phenoxy ring and on the nitrogen atom at the 4-position was examined. At GluA2......-ray scattering (SAXS) experiments using isolated GluA2 ligand-binding domain (GluA2-LBD) are consistent with binding of one molecule of 11m per dimer interface, contrary to most benzothiadiazine dioxides developed to date. This observation was confirmed by the X-ray structure of 11m bound to GluA2-LBD and by NMR......(Q) expressed in HEK293 cells (calcium flux experiment), the most potent compound was 11m (4-cyclopropyl-7-(3-methoxyphenoxy)-3,4-dihydro-2H-1,2,4-benzothiadiazine 1,1-dioxide, EC50 = 2.0 nM). The Hill coefficient in the screening and the shape of the dimerization curve in small-angle X...

  17. Synthesis and evaluation of 7-substituted 4-aminoquinoline analogues for antimalarial activity.

    Science.gov (United States)

    Hwang, Jong Yeon; Kawasuji, Takashi; Lowes, David J; Clark, Julie A; Connelly, Michele C; Zhu, Fangyi; Guiguemde, W Armand; Sigal, Martina S; Wilson, Emily B; Derisi, Joseph L; Guy, R Kiplin

    2011-10-27

    We previously reported that substituted 4-aminoquinolines with a phenyl ether substituent at the 7-position of the quinoline ring and the capability of intramolecular hydrogen bonding between the protonated amine on the side chain and a hydrogen bond acceptor on the amine's alkyl substituents exhibited potent antimalarial activity against the multidrug resistant strain P. falciparum W2. We employed a parallel synthetic method to generate diaryl ether, biaryl, and alkylaryl 4-aminoquinoline analogues in the background of a limited number of side chain variations that had previously afforded potent 4-aminoquinolines. All subsets were evaluated for their antimalarial activity against the chloroquine-sensitive strain 3D7 and the chloroquine-resistant K1 strain as well as for cytotoxicity against mammalian cell lines. While all three arrays showed good antimalarial activity, only the biaryl-containing subset showed consistently good potency against the drug-resistant K1 strain and good selectivity with regard to mammalian cytotoxicity. Overall, our data indicate that the biaryl-containing series contains promising candidates for further study.

  18. Preparation, characterization and biological activity of C8-substituted cytokinins

    Czech Academy of Sciences Publication Activity Database

    Zahajská, Lenka; Nisler, Jaroslav; Voller, Jiří; Gucký, Tomáš; Pospíšil, Tomáš; Spíchal, Lukáš; Strnad, Miroslav

    2017-01-01

    Roč. 135, MAR (2017), s. 115-127 ISSN 0031-9422 Institutional support: RVO:61389030 Keywords : potential purine antagonists * arabidopsis-thaliana * nucleosides * derivatives * thidiazuron * specificity * receptors * kinetin * Organic synthesis * Cytokinin bioassay * AHK3 and CRE1/AHK4 bacterial receptor assay * C8-substituted cytokinin Subject RIV: CE - Biochemistry OBOR OECD: Organic chemistry Impact factor: 3.205, year: 2016

  19. Ring-substituted 4-Hydroxy-1H-quinolin-2-ones: Preparation and Biological Activity

    Directory of Open Access Journals (Sweden)

    Jiri Dohnal

    2009-03-01

    Full Text Available In the study, a series of twelve ring-substituted 4-hydroxy-1H-quinolin-2-one derivatives were prepared. The procedures for synthesis of the compounds are presented. The compounds were analyzed using RP-HPLC to determine lipophilicity and tested for their photosynthesis-inhibiting activity using spinach (Spinacia oleracea L. chloroplasts. All the synthesized compounds were also evaluated for antifungal activity using in vitro screening with eight fungal strains. For all the compounds, the relationships between the lipophilicity and the chemical structure of the studied compounds are discussed, as well as their structure-activity relationships (SAR.

  20. Solvent substitution

    Energy Technology Data Exchange (ETDEWEB)

    1990-01-01

    The DOE Environmental Restoration and Waste Management Office of Technology Development and the Air Force Engineering and Services Center convened the First Annual International Workshop on Solvent Substitution on December 4--7, 1990. The primary objectives of this joint effort were to share information and ideas among attendees in order to enhance the development and implementation of required new technologies for the elimination of pollutants associated with industrial use of hazardous and toxic solvents; and to aid in accelerating collaborative efforts and technology transfer between government and industry for solvent substitution. There were workshop sessions focusing on Alternative Technologies, Alternative Solvents, Recovery/Recycling, Low VOC Materials and Treatment for Environmentally Safe Disposal. The 35 invited papers presented covered a wide range of solvent substitution activities including: hardware and weapons production and maintenance, paint stripping, coating applications, printed circuit boards, metal cleaning, metal finishing, manufacturing, compliance monitoring and process control monitoring. This publication includes the majority of these presentations. In addition, in order to further facilitate information exchange and technology transfer, the US Air Force and DOE solicited additional papers under a general Call for Papers.'' These papers, which underwent review and final selection by a peer review committee, are also included in this combined Proceedings/Compendium. For those involved in handling, using or managing hazardous and toxic solvents, this document should prove to be a valuable resource, providing the most up-to-date information on current technologies and practices in solvent substitution. Individual papers are abstracted separated.

  1. Thermodynamic studies on charge-coupled substituted synthetic monazite

    Energy Technology Data Exchange (ETDEWEB)

    Rawat, D. [Product Development Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Phapale, S. [Chemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Mishra, R., E-mail: mishrar@barc.gov.in [Chemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Dash, S. [Product Development Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India)

    2017-04-15

    Phosphate-based monazite ceramic is considered worldwide as a potential crystalline host matrix for immobilization of long-lived tri- and tetra-valent actinides present in high-level nuclear waste. Monazite is chemically stable with respect to the leaching processes and has high radiation stability. The present paper describes the influence of charged coupled (Ca{sup 2+}, Th{sup 4+}) substitution in place of La{sup 3+} on thermodynamic stability of synthetic monazite ceramics. XRD-analysis of Ca, Th substituted LaPO{sub 4} viz., La{sub 1-x}Ca{sub x/2}Th{sub x/2}PO{sub 4} (0 ≤ x ≤ 1) points to the formation of ideal solid-solution in the entire range of composition. However, thermodynamic analysis indicates deviation from ideal solid-solution with a minima at x = 0.25. The substituted La{sub 1-x}Ca{sub x/2}Th{sub x/2}PO{sub 4} system is found to be iso-entropic and stabilized mainly by enthalpy. Enthalpies of formation as a function of Ca{sup 2+}, Th{sup 4+} substitution were analysed to provide insights into the development of thermodynamically stable nuclear waste matrix.

  2. Growth of N-substituted polypyrrole layers in ionic liquids: synthesis and its electrochromic properties

    Czech Academy of Sciences Publication Activity Database

    Ahmad, S.; Sen Gursoy, S.; Kazim, Samrana; Uygun, A.

    2012-01-01

    Roč. 99, SI (2012), s. 95-100 ISSN 0927-0248 Institutional research plan: CEZ:AV0Z40500505 Keywords : polypyrrole * substituted polypyrrole * ionic liquids Subject RIV: CD - Macromolecular Chemistry Impact factor: 4.630, year: 2012

  3. More Similar but Less Satisfying: Comparing Preferences for and the Efficacy of Within- and Cross-Category Substitutes for Food.

    Science.gov (United States)

    Huh, Young Eun; Vosgerau, Joachim; Morewedge, Carey K

    2016-06-01

    When people cannot get what they want, they often satisfy their desire by consuming a substitute. Substitutes can originate from within the taxonomic category of the desired stimulus (i.e., within-category substitutes) or from a different taxonomic category that serves the same basic goal (i.e., cross-category substitutes). Both a store-brand chocolate (within-category substitute) and a granola bar (cross-category substitute), for example, can serve as substitutes for gourmet chocolate. Here, we found that people believe that within-category substitutes, which are more similar to desired stimuli, will more effectively satisfy their cravings than will cross-category substitutes (Experiments 1, 2a, and 2b). However, because within-category substitutes are more similar than cross-category substitutes to desired stimuli, they are more likely to evoke an unanticipated negative contrast effect. As a result, unless substitutes are equivalent in quality to the desired stimulus, cross-category substitutes more effectively satisfy cravings for the desired stimulus (Experiments 3 and 4). © The Author(s) 2016.

  4. Metal substitution in the active site of nitrogenase MFe(7)S(9) (M = Mo(4+), V(3+), Fe(3+)).

    Science.gov (United States)

    Lovell, Timothy; Torres, Rhonda A; Han, Wen-Ge; Liu, Tiqing; Case, David A; Noodleman, Louis

    2002-11-04

    The unifying view that molybdenum is the essential component in nitrogenase has changed over the past few years with the discovery of a vanadium-containing nitrogenase and an iron-only nitrogenase. The principal question that has arisen for the alternative nitrogenases concerns the structures of their corresponding cofactors and their metal-ion valence assignments and whether there are significant differences with that of the more widely known molybdenum-iron cofactor (FeMoco). Spin-polarized broken-symmetry (BS) density functional theory (DFT) calculations are used to assess which of the two possible metal-ion valence assignments (4Fe(2+)4Fe(3+) or 6Fe(2+)2Fe(3+)) for the iron-only cofactor (FeFeco) best represents the resting state. For the 6Fe(2+)2Fe(3+) oxidation state, the spin coupling pattern for several spin state alignments compatible with S = 0 were generated and assessed by energy criteria. The most likely BS spin state is composed of a 4Fe cluster with spin S(a) = (7)/(2) antiferromagnetically coupled to a 4Fe' cluster with spin S(b) = (7)/(2). This state has the lowest DFT energy for the isolated FeFeco cluster and displays calculated Mössbauer isomer shifts consistent with experiment. Although the S = 0 resting state of FeFeco has recently been proposed to have metal-ion valencies of 4Fe(2+)4Fe(3+) (derived from experimental Mössbauer isomer shifts), our isomer shift calculations for the 4Fe(2+)4Fe(3+) oxidation state are in poorer agreement with experiment. Using the Mo(4+)6Fe(2+)Fe(3+) oxidation level of the cofactor as a starting point, the structural consequences of replacement of molybdenum (Mo(4+)) with vanadium (V(3+)) or iron (Fe(3+)) in the cofactor have been investigated. The size of the cofactor cluster shows a dependency on the nature of the heterometal and increases in the order FeMoco < FeVco < FeFeco.

  5. Chemoenzymatic synthesis of a series of 4-substituted glutamate analogues and pharmacological characterization at human glutamate transporters subtypes 1-3

    DEFF Research Database (Denmark)

    Alaux, Sebastien; Kusk, Mie; Sagot, Emanuelle

    2005-01-01

    A series of nine L-2,4-syn-4-alkylglutamic acid analogues (1a-i) were synthesized in high yield and high enantiomeric excess (>99% ee) from their corresponding 4-substituted ketoglutaric acids (2a-i), using the enzyme aspartate aminotransferase (AAT) from pig heart or E. coli. The synthesized com...... subtypes EAAT1-3 while maintaining inhibitory activity....

  6. Study of Ti4+ substitution in ZrW2O8 negative thermal expansion materials

    International Nuclear Information System (INIS)

    Buysser, Klaartje de; Driessche, Isabel van; Putte, Bart van de; Schaubroeck, Joseph; Hoste, Serge

    2007-01-01

    Powder XRD-analysis and thermo-mechanical analysis on sintered TiO 2 -WO 3 -ZrO 2 mixtures revealed the formation of Zr 1-x Ti x W 2 O 8 solid solutions. A noticeable decrease in unit cell parameter 'a' and in the order-disorder transition temperature could be seen in the case of Zr 1-x Ti x W 2 O 8 solid solutions. Studies performed on other ZrW 2 O 8 solid solutions have attributed an increase in phase transition temperature to a decrease in free lattice volume, whereas a decrease in phase transition temperature was suggested to be due to the presence of a more disordered state. Our studies indicate that the phase transition temperature in our materials is strongly influenced by the bond dissociation energy of the substituting ion-oxygen bond. A decrease in bond strength may compensate for the effect of a decrease in lattice free volume, lowering the phase transition temperature as the degree of substitution by Ti 4+ increases. This hypothesis is proved by differential scanning calorimetry. - Graphical abstract: This study indicates that the phase transition temperature in our materials Zr 1-x Ti x W 2 O 8 is strongly influenced by the bond dissociation energy of the substituting ion-oxygen bond. A decrease in bond strength may compensate for the effect of a decrease in lattice-free volume, lowering the phase transition temperature

  7. One-pot regioselective synthesis of nitrophenyloxazolinyl styrene oxides by the Darzens reaction of vicarious nucleophilic substitution-formed carbanions of 2-dichloromethyl-4,4-dimethyloxazoline.

    Science.gov (United States)

    Florio, Saverio; Lorusso, Patrizia; Granito, Catia; Luisi, Renzo; Troisi, Luigino

    2004-07-23

    The vicarious nucleophilic substitution reaction of dichloromethyloxazoline 2 with nitrobenzene has been investigated. Treatment of 2 with t-BuOK followed by the addition of nitrobenzene leads to benzylic carbanions 4 or 9 depending upon the solvent used (DMSO, DMF, or THF). Subsequent treatment of 4 or 9 with aldehydes, in a Darzens-like reaction, furnishes very good yields of nitrophenyl oxazolinyloxiranes 8 and 11. 1,2-Dioxazolinyl-1,2-dinitrophenylethene 7 forms quantitatively when carbanion 4 is allowed to warm to room temperature in the absence of external electrophiles.

  8. The Resurgence of Ideology in Bernard Shaw’s Mrs Warren’s Profession (1893)

    OpenAIRE

    Guy, Stéphane

    2017-01-01

    In the last of his Plays Unpleasant, Shaw delves into the economic roots of prostitution, deconstructing the woman-with-a-past sham and its underlying conservative ideology. The socialist playwright and theorist seeks to lay the blame on the capitalist system and on a middle-class public all too eager to ascribe prostitution to merely individual villainy. Echoing the standpoint of Victorian social reformers, Mrs Warren’s Profession explodes the well-made play pattern to shatter commonplaces a...

  9. Synthesis and Positive Inotropic Activity of [1,2,4]Triazolo[4,3-a] Quinoxaline Derivatives Bearing Substituted Benzylpiperazine and Benzoylpiperazine Moieties

    Directory of Open Access Journals (Sweden)

    Xue-Kun Liu

    2017-02-01

    Full Text Available In an attempt to search for more potent positive inotropic agents, two series of [1,2,4]triazolo[4,3-a] quinoxaline derivatives bearing substituted benzylpiperazine and benzoylpiperazine moieties were synthesized and their positive inotropic activities evaluated by measuring left atrial stroke volume in isolated rabbit heart preparations. Several compounds showed favorable activities compared with the standard drug, milrinone. Compound 6c was the most potent agent, with an increased stroke volume of 12.53% ± 0.30% (milrinone: 2.46% ± 0.07% at 3 × 10−5 M. The chronotropic effects of compounds having considerable inotropic effects were also evaluated.

  10. Synthesis and magnetic properties of LiFePO4 substitution magnesium

    Science.gov (United States)

    Choi, Hyunkyung; Kim, Min Ji; Hahn, Eun Joo; Kim, Sam Jin; Kim, Chul Sung

    2017-06-01

    LiFe0.9Mg0.1PO4 sample was prepared by using a solid-state reaction method, and the temperature-dependent magnetic properties of the sample were studied. The X-ray diffraction (XRD) pattern showed an olivine-type orthorhombic structure with space group Pnma based on Rietveld refinement method. The effect of Mg substitution in antiferromagnetic LiFe0.9Mg0.1PO4 was investigated using a vibrating sample magnetometer (VSM) and Mössbauer spectroscopy. The temperature-dependence of the magnetization curves of LiFe0.9Mg0.1PO4 shows abnormal antiferromagnetic behavior with ordering temperature. Sudden changes in both the magnetic hyperfine field (Hhf) and its slope below 15 K suggest that magnetic phase transition associated to the abrupt occurrence of spin-reorientation. The Néel temperature (TN) and spin-reorientation temperature (TS) of LiFe0.9Mg0.1PO4 are lower than those of pure LiFePO4 (TN = 51 K, TS = 23 K). This is due to the Fe-O-Fe superexchange interaction being larger than that of the Fe-O-Mg link. Also, we have confirmed a change in the electric quadrupole splitting (ΔEQ) by the spin-orbit coupling effect and the shape of Mössbauer spectrum has provided the evidence for TS and a strong crystalline field. We have found that Mg ions in LiFe0.9Mg0.1PO4 induce an asymmetric charge density due to the presence of Mg2+ ions at the FeO6 octahedral sites.

  11. Accessing simply-substituted 4-hydroxytetrahydroisoquinolines via Pomeranz–Fritsch–Bobbitt reaction with non-activated and moderately-activated systems

    Directory of Open Access Journals (Sweden)

    Marco Mottinelli

    2017-09-01

    Full Text Available Background: 1,2,3,4-Tetrahydroisoquinolines (THIQs are common motifs in alkaloids and in medicinal chemistry. Synthetic access to THIQs via the Pomeranz–Fritsch–Bobbit (PFB methodology using mineral acids for deactivated, electron-poor aromatic systems, is scarcely represented in the literature. Here, the factors controlling the regiochemical outcome of cyclization are evaluated.Results: A double reductive alkylation was telescoped into a one-pot reaction delivering good to excellent yields of desired aminoacetals for cyclization. Cyclization of activated systems proceeded smoothly under standard PFB conditions, but for non-activated systems the use of HClO4 alone was effective. When cyclization was possible in both para- and ortho-positions to the substituent, 7-substituted derivatives were formed with significant amounts of 5-substituted byproduct. The formation of the 4-hydroxy-THIQs vs the 4-methoxy-THIQ products could be controlled through modification of the reaction concentration. In addition, while a highly-activated system exclusively cyclized to the indole, this seems generally highly disfavored. When competition between 6- and 7-ring formation was investigated in non-activated systems, 5,7,8,13-tetrahydro-6,13-methanodibenzo[c,f]azonine was exclusively obtained. Furthermore, selective ring closure in the para-position could be achieved under standard PFB conditions, while a double ring closure could be obtained utilizing HClO4.Conclusion: Reactivity differences in aminoacetal precursors can be employed to control cyclization using the PFB methodology. It is now possible to select confidently the right conditions for the synthesis of N-aryl-4-hydroxy-1,2,3,4-tetrahydroisoquinolines.

  12. Accessing simply-substituted 4-hydroxytetrahydroisoquinolines via Pomeranz–Fritsch–Bobbitt reaction with non-activated and moderately-activated systems

    Science.gov (United States)

    Mottinelli, Marco; Leese, Mathew P

    2017-01-01

    Background: 1,2,3,4-Tetrahydroisoquinolines (THIQs) are common motifs in alkaloids and in medicinal chemistry. Synthetic access to THIQs via the Pomeranz–Fritsch–Bobbit (PFB) methodology using mineral acids for deactivated, electron-poor aromatic systems, is scarcely represented in the literature. Here, the factors controlling the regiochemical outcome of cyclization are evaluated. Results: A double reductive alkylation was telescoped into a one-pot reaction delivering good to excellent yields of desired aminoacetals for cyclization. Cyclization of activated systems proceeded smoothly under standard PFB conditions, but for non-activated systems the use of HClO4 alone was effective. When cyclization was possible in both para- and ortho-positions to the substituent, 7-substituted derivatives were formed with significant amounts of 5-substituted byproduct. The formation of the 4-hydroxy-THIQs vs the 4-methoxy-THIQ products could be controlled through modification of the reaction concentration. In addition, while a highly-activated system exclusively cyclized to the indole, this seems generally highly disfavored. When competition between 6- and 7-ring formation was investigated in non-activated systems, 5,7,8,13-tetrahydro-6,13-methanodibenzo[c,f]azonine was exclusively obtained. Furthermore, selective ring closure in the para-position could be achieved under standard PFB conditions, while a double ring closure could be obtained utilizing HClO4. Conclusion: Reactivity differences in aminoacetal precursors can be employed to control cyclization using the PFB methodology. It is now possible to select confidently the right conditions for the synthesis of N-aryl-4-hydroxy-1,2,3,4-tetrahydroisoquinolines. PMID:29062406

  13. Accessing simply-substituted 4-hydroxytetrahydroisoquinolines via Pomeranz-Fritsch-Bobbitt reaction with non-activated and moderately-activated systems.

    Science.gov (United States)

    Mottinelli, Marco; Leese, Mathew P; Potter, Barry V L

    2017-01-01

    Background: 1,2,3,4-Tetrahydroisoquinolines (THIQs) are common motifs in alkaloids and in medicinal chemistry. Synthetic access to THIQs via the Pomeranz-Fritsch-Bobbit (PFB) methodology using mineral acids for deactivated, electron-poor aromatic systems, is scarcely represented in the literature. Here, the factors controlling the regiochemical outcome of cyclization are evaluated. Results: A double reductive alkylation was telescoped into a one-pot reaction delivering good to excellent yields of desired aminoacetals for cyclization. Cyclization of activated systems proceeded smoothly under standard PFB conditions, but for non-activated systems the use of HClO 4 alone was effective. When cyclization was possible in both para - and ortho -positions to the substituent, 7-substituted derivatives were formed with significant amounts of 5-substituted byproduct. The formation of the 4-hydroxy-THIQs vs the 4-methoxy-THIQ products could be controlled through modification of the reaction concentration. In addition, while a highly-activated system exclusively cyclized to the indole, this seems generally highly disfavored. When competition between 6- and 7-ring formation was investigated in non-activated systems, 5,7,8,13-tetrahydro-6,13-methanodibenzo[ c , f ]azonine was exclusively obtained. Furthermore, selective ring closure in the para- position could be achieved under standard PFB conditions, while a double ring closure could be obtained utilizing HClO 4 . Conclusion: Reactivity differences in aminoacetal precursors can be employed to control cyclization using the PFB methodology. It is now possible to select confidently the right conditions for the synthesis of N- aryl-4-hydroxy-1,2,3,4-tetrahydroisoquinolines.

  14. Identification of Four Novel Synonymous Substitutions in the X-Linked Genes Neuroligin 3 and Neuroligin 4X in Japanese Patients with Autistic Spectrum Disorder

    Directory of Open Access Journals (Sweden)

    Kumiko Yanagi

    2012-01-01

    Full Text Available Mutations in the X-linked genes neuroligin 3 (NLGN3 and neuroligin 4X (NLGN4X were first implicated in the pathogenesis of X-linked autism in Swedish families. However, reports of mutations in these genes in autism spectrum disorder (ASD patients from various ethnic backgrounds present conflicting results regarding the etiology of ASD, possibly because of genetic heterogeneity and/or differences in their ethnic background. Additional mutation screening study on another ethnic background could help to clarify the relevance of the genes to ASD. We scanned the entire coding regions of NLGN3 and NLGN4X in 62 Japanese patients with ASD by polymerase chain reaction-high-resolution melting curve and direct sequencing analyses. Four synonymous substitutions, one in NLGN3 and three in NLGN4X, were identified in four of the 62 patients. These substitutions were not present in 278 control X-chromosomes from unrelated Japanese individuals and were not registered in the database of Single Nucleotide Polymorphisms build 132 or in the Japanese Single Nucleotide Polymorphisms database, indicating that they were novel and specific to ASD. Though further analysis is necessary to determine the physiological and clinical importance of such substitutions, the possibility of the relevance of both synonymous and nonsynonymous substitutions with the etiology of ASD should be considered.

  15. The 4s24p3-4s4p4 transition in AsI-like AgXV

    International Nuclear Information System (INIS)

    Dong Chenzhong; Zhao Jinbao

    1992-01-01

    Some terms of the 4s 4p 4 configuration in RuXII, RhXIII and PdXIV ions can be improved and all the energy values of the configuration in AgXV can be predicted theoretically by means of a configuration-interaction ab initio analysis for the level structure of the 4s 4p 4 configuration along the AsI sequence of KrIV-AgXV ions. Calculations of the wavelengths and oscillator strenghts are presented for the 4s 2 4p 3 -4s 4p 4 transition in AgXV. (orig.)

  16. Synergetic Fe substitution and carbon connection in LiMn1−xFexPO4/C cathode materials for enhanced electrochemical performances

    International Nuclear Information System (INIS)

    Yan, Su-Yuan; Wang, Cheng-Yang; Gu, Rong-Min; Sun, Shuai; Li, Ming-Wei

    2015-01-01

    Highlights: • LiMn 0.6 Fe 0.4 PO 4 /C cathode material shows enhanced rate capability. • The Fe doped in the partial Mn sites could significantly facilitate the Li ions transfer. • The enhanced Li + ions diffusion contributes to the optimized rate capability of LiMn 0.6 Fe 0.4 PO 4 . • ACM carbonization forms well carbon coating and a 3D carbon network structure. - Abstract: To enhance the rate and cyclic performances of LiMnPO 4 cathode material for lithium-ion batteries, Mn is partially substituted with Fe, and LiMn 1−x Fe x PO 4 (x = 0.2, 0.3, 0.4, 0.5) solid solutions are synthesized and investigated. Amphiphilic carbonaceous material (ACM) forms well carbon coating and connects the LiMn 1−x Fe x PO 4 crystallites by a three-dimensional (3D) carbon network. The synergetic Fe substitution and carbon connection obviously improve the samples’ rate capacities and cyclic stability. The optimized LiMn 0.6 Fe 0.4 PO 4 /C sample delivers discharge capacities of 160 mA h g −1 at 0.05 C, 148 mA h g −1 at 1 C, and 115 mA h g −1 at 20 C. All samples have well capacity retention (>92%) after 50 charge/discharge cycles at 1 C. The enhanced electrochemical properties are mainly attributed to the improvement of Li ion and electron transport in the LiMn 1−x Fe x PO 4 /C samples, respectively mainly resulting from their modified crystal structures caused by Fe substitution and the 3D carbon coating/connection originating from ACM carbonization. LiMn 1−x Fe x PO 4 materials exhibit two discharge plateaus at ∼4.0 and ∼3.5 V (vs. Li + /Li), whose heights respectively reflect the redox potentials of Mn 3+ /Mn 2+ and Fe 3+ /Fe 2+ couples. The plateaus’ lengths correspond to the Mn/Fe ratio in LiMn 1−x Fe x PO 4 and are affected by the kinetic behavior of samples. Though the ∼4.0 V plateau shrinks with increasing discharge rate, the ∼3.5 V plateau may slightly elongate. Moreover, the Fe substituted in the partial Mn sites could significantly improve

  17. Orbital-selective Mott phase of Cu-substituted iron-based superconductors

    International Nuclear Information System (INIS)

    Liu, Yang; Zhao, Yang-Yang; Song, Yun

    2016-01-01

    We study the phase transition in Cu-substituted iron-based superconductors with a new developed real-space Green’s function method. We find that Cu substitution has strong effect on the orbital-selective Mott transition introduced by the Hund’s rule coupling. The redistribution of the orbital occupancy which is caused by the increase of the Hund’s rule coupling, gives rise to the Mott–Hubbard metal-insulator transition in the half-filled d xy orbital. We also find that more and more electronic states appear inside that Mott gap of the d xy orbital with the increase of Cu substitution, and the in-gap states around the Fermi level are strongly localized at some specific lattice sites. Further, a distinctive phase diagram, obtained for the Cu-substituted Fe-based superconductors, displays an orbital-selective insulating phase, as a result of the cooperative effect of the Hund’s rule coupling and the impurity-induced disorder. (paper)

  18. Crystallochemical features of solid solutions based on Ga/sub 2/3/Cr/sub 2/S/sub 4/

    Energy Technology Data Exchange (ETDEWEB)

    Titov, V.V.; Kesler, Ya.A.; Gordeev, I.V.; Stupnikov, V.A.

    1988-04-01

    Ga/sub 2/3/Cr/sub 2/S/sub 4/ shows a rare type of phase transition where increases in temperature and pressure produce the disordered modification. A source of disordering can be isomorphous substitution in the tetrahedral sublattice. The authors therefore made and examined solid solutions of Ga/sub (2/3-2x/3)/M/sub x/(Cr/sub 2/)S/sub 4/ type, where M = Fe, Co, Ni, Cu. Specimens containing Fe and show a quasi-continuous solid-solution series, where the Fe system obeys Vegard's rule. Specimens containing nickel show a narrow ordering range. The most interesting results have been obtained for specimens containing copper. Cu/sub x/Ga/sub 2/3(1-x)/Cr/sub 2/S/sub 4/ specimens show a transition from a structure ordered on the tetrahedral positions, symmetry F/anti/43m, to the normal-spinel structure, Fd3m.

  19. Synthesis and Characterization of an Earth-Abundant Cu2BaSn(S,Se)4 Chalcogenide for Photoelectrochemical Cell Application.

    Science.gov (United States)

    Shin, Donghyeop; Ngaboyamahina, Edgard; Zhou, Yihao; Glass, Jeffrey T; Mitzi, David B

    2016-11-17

    Cu 2 BaSnS 4-x Se x films consisting of earth-abundant metals have been examined for photocathode application. Films with different Se contents (i.e., Cu 2 BaSnS 4-x Se x with x ≤ 2.4) were synthesized using a cosputter system with post-deposition sulfurization/selenization annealing treatments. Each film adopts a trigonal P3 1 crystal structure, with progressively larger lattice constants and with band gaps shifting from 2.0 to 1.6 eV, as more Se substitutes for S in the parent compound Cu 2 BaSnS 4 . Given the suitable bandgap and earth-abundant elements, the Cu 2 BaSnS 4-x Se x films were studied as prospective photocathodes for water splitting. Greater than 6 mA/cm 2 was obtained under illumination at -0.4 V versus reversible hydrogen electrode for Pt/Cu 2 BaSnS 4-x Se x films with ∼60% Se content (i.e., x = 2.4), whereas a bare Cu 2 BaSnS 4-x Se x (x = 2.4) film yielded ∼3 mA/cm 2 at -0.4 V/RHE.

  20. Novel fluoroquinolone derivatives bearing N-thiomide linkage with 6-substituted-2-aminobenzothiazoles: Synthesis and antibacterial evaluation

    Directory of Open Access Journals (Sweden)

    Prabodh Chander Sharma

    2017-02-01

    Full Text Available A series of novel fluoroquinolone derivatives bearing N-thiomide linkage with 6-substituted-2-aminobenzothiazole substituents at the C-7 position were synthesized to obtain potent analogs active against bacterial strains. Some compounds exhibited excellent antibacterial activity against Staphylococcus auerus, Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa bacterial strains. Among all the synthesized compounds 6-nitro substituted benzothiazole along with norfloxacin (4b and gatifloxacin (4l showed MIC 05 μg/ml when tested against S. auerus. Moreover, compounds 4d, 4f and 4l showed superior MIC (15, 10, and 15 μg/ml respectively against B. subtilis. The results of the present study reveal that the compounds have significant antibacterial potential and are suitable candidates for further exploration.

  1. 4-Substituted-2-Methoxyphenol: Suitable Building Block to Prepare New Bioactive Natural-like Hydroxylated Biphenyls.

    Science.gov (United States)

    Dettori, Maria Antonietta; Fabbri, Davide; Pisano, Marina; Rozzo, Carla; Palmieri, Giuseppe; Dess, Alessandro; Dallocchio, Roberto; Delogu, Giovanna

    2015-02-01

    A small collection of eugenol- and curcumin-analog hydroxylated biphenyls was prepared by straightforward methods starting from natural 4-substituted-2-methoxyphenols and their antitumoral activity was evaluated in vitro . Two curcumin-biphenyl derivatives showed interesting growth inhibitory activities on different malignant melanoma cell lines with IC 50 ranging from 13 to 1 µM. Preliminary molecular modeling studies were carried out to evaluate conformations and dihedral angles suitable for antiproliferative activity in hydroxylated biphenyls bearing a side aliphatic chain.

  2. Muon substituted free radicals

    International Nuclear Information System (INIS)

    Burkhard, P.; Fischer, H.; Roduner, E.; Strub, W.; Gygax, F.N.; Brinkman, G.A.; Louwrier, P.W.F.; McKenna, D.; Ramos, M.; Webster, B.C.

    1984-01-01

    Spin polarized energetic positive muons are injected as magnetic probes into unsaturated organic liquids. They are implemented via fast chemical processes ( -10 s) in various molecules. Of particular interest among these are muonium substituted free radicals. The technique allows determination of accurate rate coefficients for fast chemical reactions of radicals. Furthermore, radiochemical processes occuring in picoseconds after injection of the muon are studied. Of fundamental interest are also the structural and dynamical implications of substituting a proton by a muon, or in other terms, a hydrogen atom by a muonium atom. Selected examples for each of these three types of experiments are given. (Auth.)

  3. Planar geometry of 4-substituted-2,2'-bipyridines synthesized by Sonogashira and Suzuki cross-coupling reactions

    Energy Technology Data Exchange (ETDEWEB)

    Luong Thi, T. T., E-mail: thuyltt@hnue.edu.vn; Nguyen Bich, N.; Nguyen, H. [Hanoi National University of Education, Chemistry Department (Viet Nam); Van Meervelt, L., E-mail: luc.vanmeervelt@chem.kuleuven.be [KU Leuven, Chemistry Department (Belgium)

    2015-12-15

    Two 4-substituted 2,2'-bipyridines, namely 4-(ferrocenylethynyl)-2,2'-bipyridine (I) and 4-ferrocenyl-2,2'-bipyridine (II) have been synthesized and fully characterized via single-crystal X-ray diffraction and {sup 1}H and {sup 13}C NMR analyses. The π-conjugated system designed from 2,2'-bipyridine modified with the ferrocenylethynyl and ferrocenyl groups shows the desired planarity. In the crystal packing of I and II, the molecules arrange themselves in head-to-tail and head-to-head motifs, respectively, resulting in consecutive layers of ferrocene and pyridine moieties.

  4. Fluorine Substituted 1,2,4-Triazinones as Potential Anti-HIV-1 and CDK2 Inhibitors

    Directory of Open Access Journals (Sweden)

    Mohammed S. I. Makki

    2014-01-01

    Full Text Available Fluorine substituted 1,2,4-triazinones have been synthesized via alkylation, amination, and/or oxidation of 6-(2-amino-5-fluorophenyl-3-thioxo-3,4-dihydro-1,2,4-triazin-5(2H-one 1 and 4-fluoro-N-(4-fluoro-2-(5-oxo-3-thioxo-2,3,4,5-tetrahydro-1,2,4-triazin-6-ylphenylbenzamide 5 as possible anti-HIV-1 and CDK2 inhibitors. Alkylation on positions 2 and 4 in 1,2,4-triazinone gave compounds 6–8. Further modification was performed by selective alkylation and amination on position 3 to form compounds 9–15. However oxidation of 5 yielded compounds 16–18. Structures of the target compounds have been established by spectral analysis data. Five compounds (5, 11, 14, 16, and 17 have shown very good anti-HIV activity in MT-4 cells. Similarly, five compounds (1, 3, and 14–16 have exhibited very significant CDK2 inhibition activity. Compounds 14 and 16 were found to have dual anti-HIV and anticancer activities.

  5. Studies towards C-3 functionalization of β-lactams using substituted ...

    Indian Academy of Sciences (India)

    β-lactams using substituted allylsilanes. 1753. 2. Mascaretti O A, Boschetti C E, Danelon G O, Mata E G and Roveri O A 1995 Current Med. Chem. 1 441. 3. Hatanaka N, Abe R and Ojima I 1981 Chem. Lett. 10 1297. 4. O'Boyle N, Carr M, Greene L, Bergin O, Nathwani S,. McCabe T, Lloyd D, Zisterer D and Meegan M 2010.

  6. THE EFFECT OF EXPIRED BREAD MEAL AS CORN SUBSTITUTION IN DIET ON BROILER PERFORMANCE

    Directory of Open Access Journals (Sweden)

    S. Kismiati

    2014-10-01

    Full Text Available An experiment was conducted to investigate the expired bread meal used as corn substitution in thebroiler diets to optimally the product performance. One hundred day old chick (DOC male broilerswere given the same diet until 2 weeks old, and then given the treatment diet until 7 weeks of age. ACompletely Randomized Design was used in this study. Data were analyzed by variance of analysis, andfollowed by Duncan’s Multiple Range Test The treatments were : T0 = control feed (without expiredbread meal, T1 = corn substituted with 10% expired bread meal, T2 = corn substituted with 20%expired bread meal, T3 = corn substituted with 30% expired bread meal and T4 = corn substituted with40% expired bread meal. The result indicated that corn substituted with expired bread meal up to 40%has not significantly affected on carcass weight, carcass percentage and feed conversion, but decreasedsignificantly on feed consumption and body weight gain. It can be concluded that the use of expiredbread meal 30% of the proportion of corn produced the most optimal broiler performance. Thesubstitution corn with expired bread meal 40% was decreased body weight gain.

  7. Zn substitution NiFe{sub 2}O{sub 4} nanoparticles with enhanced conductivity as high-performances electrodes for lithium ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Mao, Junwei [Guang dong Engineering Technology Research Center of Efficient Green Energy and Environmental Protection Materials, Guangzhou 510006 (China); Guang dong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510006 (China); Hou, Xianhua, E-mail: houxh@scnu.edu.cn [Guang dong Engineering Technology Research Center of Efficient Green Energy and Environmental Protection Materials, Guangzhou 510006 (China); Guang dong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510006 (China); Huang, Fengsi; Shen, Kaixiang [Guang dong Engineering Technology Research Center of Efficient Green Energy and Environmental Protection Materials, Guangzhou 510006 (China); Guang dong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510006 (China); Lam, Kwok-ho [Department of Electrical Engineering, The Hong Kong Polytechnic University, Hunghom, Kowloon 999077 (Hong Kong); Ru, Qiang [Guang dong Engineering Technology Research Center of Efficient Green Energy and Environmental Protection Materials, Guangzhou 510006 (China); Guang dong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510006 (China); Hu, Shejun, E-mail: husj@scnu.edu.cn [Guang dong Engineering Technology Research Center of Efficient Green Energy and Environmental Protection Materials, Guangzhou 510006 (China); Guang dong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510006 (China)

    2016-08-15

    Zn{sup 2+} ion substituted nickel ferrite nanomaterials with the chemical formula Ni{sub 1−x}Zn{sub x}Fe{sub 2}O{sub 4} for x = 0, 0.3, 0.5, 0.7 and 1 have been synthesized by a facile green-chemical hydrothermal method as anode materials in lithium ion battery. The morphology and structure of the samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The physical and electrochemical properties were tested by electrochemical system. Furthermore, the energetic and electronic properties of the samples were investigated by density functional calculations. The results suggest that Zn substitution can affect the conduction performance of the zinc - nickel ferrite. Meanwhile, electrochemical results show that an enhancement in the capacity with increasing Zn concentration is observed especially for x = 0.3 which exhibit high discharge capacity of 1416 mAh g{sup −1}at the end of 100th cycle. Moreover, the theoretical research method with high yield synthesis strategy described in the present work holds promise for the general fabrication of other metallic elements substitution in complex transition metal oxides for high power LIBs. - Highlights: • Ni{sub 1−x}Zn{sub x}Fe{sub 2}O{sub 4} anodes have been synthesized by hydrothermal method. • First principles calculation was used to investigate the conduction performance. • Electrochemical performance was enhanced with Zn substitution.

  8. Synthesis of 1-Substituted Carbazolyl-1,2,3,4-tetrahydro- and Carbazolyl-3,4-dihydro-β-carboline Analogs as Potential Antitumor Agents

    Directory of Open Access Journals (Sweden)

    Ji-Wang Chern

    2011-02-01

    Full Text Available A series of 1-substituted carbazolyl-1,2,3,4-tetrahydro- and carbazolyl-3,4-dihydro-b-carboline analogs have been synthesized and evaluated for antitumor activity against human tumor cells including KB, DLD, NCI-H661, Hepa, and HepG2/A2 cell lines. Among these, compounds 2, 6, 7, and 9 exhibited the most potent and selective activity against the tested tumor cells. As for inhibition of topoisomerase II, compounds 1–14 and 18 showed better activity than etoposide. Among them, compounds 3, 4, 7, 9, and 10 exhibited potent activity. The structure and activity relationship (SAR study revealed correlation between carbon numbers of the side chain and biological activities. The molecular complex with DNA for compound 2 was proposed.

  9. Comparison of Inhibitory Activities of meta and para Substituted N-aryl 3-Hydroxypyridin-4-one Mannosides Towards Type 1 Fimbriated E. coli

    Directory of Open Access Journals (Sweden)

    Vesna Petrović Peroković

    2016-06-01

    Full Text Available In uropathogenic Escherichia coli, mannose-specific adhesion is mediated by the FimH adhesin located at the tip of type 1 fimbriae. Novel mannosylated N-aryl substituted 3-hydroxypyridin-4ones with meta substituents on the aryl part of the molecule were prepared, and their inhibitory properties towards the adhesion of E. coli to guinea pig erythrocytes explored using the hemagglutination assay. These results were compared with inhibitory potencies of analogous para derivatives. The assays revealed greater preference of FimH towards para substituted compounds in general, with p-nitro and p-methoxy substituted substrates being much more effective then the hydrophobic p-methyl compound. When substituents are in meta position the positive affect on the binding of compounds in the FimH binding site was observed with all compounds tested but the structure with an alkyl group was shown to be the most effective one. This study provides guidelines for the rational design of novel, more effective series of FimH antagonists. This work is licensed under a Creative Commons Attribution 4.0 International License.

  10. Synthesis and photophysical and electroluminescent properties of poly(1,4-phenylene–ethynylene)-alt-poly(1,4-phenylene–vinylene)s with various dissymmetric substitution of alkoxy side chains

    Czech Academy of Sciences Publication Activity Database

    Bouguerra, N.; Růžička, Aleš; Ulbricht, C.; Enengl, C.; Enengl, S.; Pokorná, Veronika; Výprachtický, Drahomír; Tordin, E.; Aitout, R.; Cimrová, Věra; Egbe, D. A. M.

    2016-01-01

    Roč. 49, č. 2 (2016), s. 455-464 ISSN 0024-9297 R&D Projects: GA ČR(CZ) GA13-26542S; GA ČR(CZ) GAP106/12/0827 Institutional support: RVO:61389013 Keywords : poly(1,4-phenylene-ethynylene)-alt-poly(1,4-phenylene-vinylene)s * dissymmetric side chains * synthesis Subject RIV: CD - Macromolecular Chemistry Impact factor: 5.835, year: 2016

  11. Substituted 4-hydroxy-1,2,3-triazoles

    DEFF Research Database (Denmark)

    Pippione, Agnese C.; Dosio, Franco; Ducime, Alex

    2015-01-01

    the distal (S)-glutamic acid carboxyl group using the 4-hydroxy-1,2,3-triazole moiety is applied, to obtain two promising glutamate analogs. In the second example, a scaffold hopping approach is applied, replacing the phenolic moiety present in MDG-1-33A, a potent inhibitor of Onchocerca volvulus chitinase...

  12. Effect of In substitution on structural, dielectric and magnetic properties of CuFe{sub 2}O{sub 4} nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Manikandan, V., E-mail: manikandan570@gmail.com [Department of Physics, Government College of Technology, Coimbatore, Tamilnadu 13 (India); Vanitha, A. [Department of Physics, Government College of Technology, Coimbatore, Tamilnadu 13 (India); Ranjith Kumar, E., E-mail: ranjueaswar@gmail.com [Department of Physics, Dr. NGP Institute of Technology, Coimbatore, Tamilnadu 48 (India); Chandrasekaran, J. [Department of Physics, Sri Ramakrishna Mission Vidyalaya College of Arts & Science, Coimbatore, Tamilnadu 20 (India)

    2017-06-15

    Highlights: • Peak shift is due to smaller ionic radius of Cu than In element. • Particle size is increased and also lattice constant increased and then decreased with respect to sintering temperature. • The average particle size is estimated in the range of 30–50 nm. - Abstract: Cu ferrite and In substituted Cu ferrite has been successfully synthesized (In{sub x}Cu{sub 1−x}Fe{sub 2}O{sub 4}; x = 0.0, 0.2) at pH 11 and sintered at 300 °C, 600 °C, 900 °C. From the XRD analysis, the ferrite phase is confirmed and particle size varied from 28 to 37 nm owing to sintering temperature. TEM microstructure confirms that samples having polycrystalline nature because of superimposition of bright spots. FT-IR spectra exhibit general behaviour of ferrite. The significant change of dielectric constant has been noticed from dielectric measurement while substitution of In element. The room temperature magnetic measurements demonstrate a solid impact of sintering temperature and In substitution on saturation magnetization and coercivity.

  13. Effects of the substitution of iron for cobalt on the crystal and magnetic properties of PrCo4-xFexM (M=Al and Ga)

    International Nuclear Information System (INIS)

    Zlotea, C.; Isnard, O.

    2003-01-01

    We report on the structural and magnetic properties of PrCo 4-x Fe x M where x=0-4 and M=Al and Ga. The iron solubility limit in these phases is determined by means of X-ray diffraction and scanning electron microscopy. Our study confirms that single phase samples crystallizing in the CaCu 5 -type structure are stabilized for x 5 structure but with a slight preference for the 3g site. The saturation magnetization and the Curie temperature increase upon the iron substitution. The PrCo 4-x Fe x M compounds present spin reorientation transitions, whatever the substituting M and the Fe content. The substitution of iron for cobalt induces a significant increase of the spin reorientation temperature. Neutron and X-ray powder diffraction experiments as well as magnetic measurements are combined in order to clarify the effects of the presence of iron on the magnetocrystalline anisotropy and the spin reorientation transition. Finally, the magnetic phase diagrams of PrCo 4-x Fe x M (M=Al and Ga) have been determined in the whole ordered temperature range

  14. Synthesis and characterization of tritium labeled N-((R)-1-((S)-4-(4-chlorophenyl)-4-hydroxy-3,3-dimethylpiperidin-1-yl)-3-methyl-1-oxobutan-2-yl)-3-sulfamoylbenzamide.

    Science.gov (United States)

    Hong, Yang; Hynes, John; Tian, Yuan; Balasubramanian, Balu; Bonacorsi, Samuel

    2015-08-01

    N-((R)-1-((S)-4-(4-chlorophenyl)-4-hydroxy-3,3-dimethylpiperidin-1-yl)-3-methyl-1-oxobutan-2-yl)-3-sulfamoylbenzamide is a potent C-C chemokine receptor 1 (CCR1) antagonist. The compound, possessing benzamide functionality, successfully underwent tritium/hydrogen (T/H) exchange with an organoiridium catalyst (Crabtree's catalyst). The labeling pattern in the product was studied with liquid chromatography-mass spectrometry, time-of-flight mass spectrometry, and (3) H-NMR. Overall, multiple labeled species were identified. In addition to the anticipated incorporation of tritium in the benzamide moiety, tritium labeling was observed in the valine portion of the molecule including substitution at its chiral carbon. Using authentic standards, liquid chromatography analysis of the labeled compound showed complete retention of stereochemical configuration. Copyright © 2015 John Wiley & Sons, Ltd.

  15. Instability of displacement of Oldroyd-B fluid by air in a Hele-Shaw cell

    Science.gov (United States)

    Daripa, Prabir

    2014-03-01

    We study the displacement of an Oldroyd-B fluid in a Hele-Shaw cell when driven by air. In particular, we explicitly obtain an analytical expression for the growth rate of instability which depends on the relaxation and retardation (time) constants, denoted by λ, and λ1 respectively, appearing in the Oldroyd-B constitutive relations. When these two constants are zero, we recover the classical Saffman-Taylor result for a Newtonian liquid displaced by air. Our results show that this displacement process is more unstable than the case when a Newtonian fluid is displaced by air. The analytical results are plotted and compared with numerical results on this unstable displacement process available in the literature. The agreement is found to be excellent. In particular, results show that the non-Newtonian case (i.e., Oldroyd-B) is more unstable than the Newtonian case. Supported by an NPRP Grant # 08-777-1-141 from the Qatar National Research Fund (a member of the Qatar Foundation). The statements made herein are solely the responsibility of the author.

  16. Copper(II)-catalyzed enantioselective hydrosilylation of halo-substituted alkyl aryl and heteroaryl ketones: asymmetric synthesis of (R)-fluoxetine and (S)-duloxetine.

    Science.gov (United States)

    Zhou, Ji-Ning; Fang, Qiang; Hu, Yi-Hu; Yang, Li-Yao; Wu, Fei-Fei; Xie, Lin-Jie; Wu, Jing; Li, Shijun

    2014-02-14

    A set of reaction conditions has been established to facilitate the non-precious copper-catalyzed enantioselective hydrosilylation of a number of structurally diverse β-, γ- or ε-halo-substituted alkyl aryl ketones and α-, β- or γ-halo-substituted alkyl heteroaryl ketones under air to afford a broad spectrum of halo alcohols in high yields and good to excellent enantioselectivities (up to 99% ee). The developed procedure has been successfully applied to the asymmetric synthesis of antidepressant drugs (R)-fluoxetine and (S)-duloxetine, which highlighted its synthetic utility.

  17. Structure of thallium and lead calculated from Shaw local pseudopotential and molecular dynamics

    Directory of Open Access Journals (Sweden)

    Gasser J. G.

    2011-05-01

    Full Text Available Recently, we (Es Sbihi Phil. Mag 2010 have successfully calculated, by molecular dynamics, the static structure factor of liquid bismuth at different temperatures. Our results were in very good agreement with the Waseda experimental data. Our assumption was to consider the true density of states which presents a gap as measured by Indlekofer (J. Non-Cryst. Solids 1989 and calculated by Hafner-Jank (Phys. Rev. B 1990 for liquid bismuth. The number of electrons at the Fermi energy has been calculated with three conduction electrons for bismuth (number of p electrons. With this assumption, the structures were determined with an effective ion-ion potential constructed from the Shaw local Optimised Model Potential (OMP and the Ichimaru-Utsumi dielectric function. In the present paper, we generalize our assumptions to liquid thallium and lead which also present such a gap. Their calculated structures are also very close to the experimental ones. This confirms that the number of conduction electrons on the Fermi sphere is consistent with the number of p electrons as has been even shown for our electronic transport properties of liquid lead (A. Ben Abdellah, Phys. Rev. B 2003.

  18. Potentiometric studies of acid-base interactions in substituted 4-nitropyridine N-oxide systems

    International Nuclear Information System (INIS)

    Gurzynski, Lukasz; Puszko, Aniela; Ostrzechowska, Agnieszka; Makowski, Mariusz; Chmurzynski, Lech

    2006-01-01

    (Acid+base) equilibrium constants, involving the acidity (pK a AC ) and cationic homoconjugation constants (in the form of lgK BHB + AC ), have been determined by the potentiometric method in 13 systems formed by substituted 4-nitropyridine N-oxides in the polar aprotic solvent, acetone (AC). The derivatives covered a wide range of proton-acceptor properties and inherent diversified tendencies towards formation of hydrogen-bonded homocomplexed cations. In addition, the constant values (expressed as pK a AN andlgK BHB + AN ) for two of the systems studied, N-oxides of 2-methylamino- and 2-ethylamino-4-nitropyridine, were determined in acetonitrile (AN). The acidity constants in the non-aqueous media studied have been found to change in line with their substituent effects and the sequence of acidity changes in water. The values of the cationic homoconjugation constants increased with increasing basicity of the N-oxides and decreased with increasing solvent basicity

  19. Potentiometric studies of acid-base interactions in substituted 4-nitropyridine N-oxide systems

    Energy Technology Data Exchange (ETDEWEB)

    Gurzynski, Lukasz [Department of General Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk (Poland); Puszko, Aniela [Department of Organic Chemistry, School of Economics, Wroclaw (Poland); Ostrzechowska, Agnieszka [Department of General Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk (Poland); Makowski, Mariusz [Department of General Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk (Poland); Chmurzynski, Lech [Department of General Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk (Poland)]. E-mail: lech@chem.univ.gda.pl

    2006-05-15

    (Acid+base) equilibrium constants, involving the acidity (pK{sub a}{sup AC}) and cationic homoconjugation constants (in the form of lgK{sub BHB{sup +}}{sup AC}), have been determined by the potentiometric method in 13 systems formed by substituted 4-nitropyridine N-oxides in the polar aprotic solvent, acetone (AC). The derivatives covered a wide range of proton-acceptor properties and inherent diversified tendencies towards formation of hydrogen-bonded homocomplexed cations. In addition, the constant values (expressed as pK{sub a}{sup AN}andlgK{sub BHB{sup +}}{sup AN}) for two of the systems studied, N-oxides of 2-methylamino- and 2-ethylamino-4-nitropyridine, were determined in acetonitrile (AN). The acidity constants in the non-aqueous media studied have been found to change in line with their substituent effects and the sequence of acidity changes in water. The values of the cationic homoconjugation constants increased with increasing basicity of the N-oxides and decreased with increasing solvent basicity.

  20. Mechanistic Studies of para-Substituted N,N'-Dibenzyl-1,4-diaminobutanes as Substrates for a Mammalian Polyamine Oxidase

    Science.gov (United States)

    Pozzi, Michelle Henderson; Gawandi, Vijay; Fitzpatrick, Paul F.

    2009-01-01

    The kinetics of oxidation of a series of para-substituted N, N'-dibenzyl-1,4-diaminobutanes by the flavoprotein polyamine oxidase from mouse have been determined to gain insight into the mechanism of amine oxidation by this member of the monoamine oxidase structural family. The kcat/Km values are maximal at pH 9, consistent with the singly charged substrate being the active form. The rate constant for flavin reduction, kred, by N,N'-dibenzyl-1,4-diaminobutane decreases about 5-fold below a pKa of ~8; this is attributed to the need for a neutral nitrogen at the site of oxidation. The kred and kcat values are comparable for each of the N, N'-dibenzyl-1,4-diaminobutanes, consistent with rate-limiting reduction. The deuterium kinetic isotope effects on kred and kcat are identical for each of the N, N'-dibenzyl-1,4-diaminobutanes, consistent with rate-limiting cleavage of the substrate CH bond. The kred values for seven different para-substituted N, N'-dibenzyl-1,4-diaminobutanes correlate with a combination of the van der Waals volume and σ value of the substrates, with ρ values of −0.59 at pH 8.6 and −0.09 at pH 6.6. These results are consistent with direct transfer of a hydride from the neutral CN bond of the substrate to the flavin as the mechanism of polyamine oxidase. PMID:19911805

  1. Base-repair substitutions alter the site-specific mutagenicity of UV and MNNG in the SUP4-o gene of the yeast

    International Nuclear Information System (INIS)

    Kunz, B.A.; Ayre, B.G.; Downes, A.M.T.; Kohalmi, S.E.; McMaster, C.R.; Peters, M.G.

    1989-01-01

    Yeast strains carrying SUP4-ogenes that habe base-pair substitutions at hotspots for UV or MNNG mutagenesis were treated with these agents. In both cases, the induced mutation frequencies were substantially reduced. Furthermore, specific substitutions at positions in SUP4-o that had not been mutated by MNNG resulted in the recovery of MNNG-induced mutations at these sites. These results demonstrate that base-pair identity is an important factor determining the site-specific mutagenicity of UV and MNNG in yeast. For UV, our findings suggest that the type of lesion that is induced, but not flanking DNA sequences, plays a role in specifying mutability at the sites examined. In contrast, DNA sequence context seems to be an important factor for MNNG mutagenesis. (author). 19 refs.; 3 tabs

  2. Substituted dihydronaphthalenes as efflux pump inhibitors of Staphylococcus aureus

    DEFF Research Database (Denmark)

    Thota, Niranjan; Reddy, Mallepally V; Kumar, Ashwani

    2010-01-01

    A new series of 3-(substituted-3,4-dihydronaphthyl)-2-propenoic acid amides has been prepared through convergent synthetic strategies and tested in combination with ciprofloxacin against NorA overexpressing Staphylococcus aureus 1199B as test strain for potentiating of the drug activity. Out of 24...... compounds evaluated, 12 compounds potentiated the activity of ciprofloxacin and resulted in 2-16 fold reduction in the MIC (4-0.5 microg/mL) of the drug. The failure of these efflux pump inhibitors (EPIs) to potentiate the activity of ciprofloxacin when tested against NorA knock out S. aureus SA-K1758...

  3. Structural and light up-conversion luminescence properties of Er{sup 3+}-Yb{sup 3+}-W{sup 6+} substituted Bi{sub 4}Ti{sub 3}O{sub 12}

    Energy Technology Data Exchange (ETDEWEB)

    Bokolia, Renuka, E-mail: renuka1274@gmail.com; Chauhan, Lalita; Sreenivas, K. [Department of Physics & Astrophysics, University of Delhi, Delhi-110007 (India); Rai, Vineet K. [Laser & Spectroscopy Laboratory, Department of Applied Physics, Indian School of Mines, Dhanbad 826 004, Jharkhand (India)

    2016-05-23

    The structural and light up-conversion (UC) luminescence properties of W{sup 6+} substituted Bi{sub 3.79}Er{sub 0.03}Yb{sub 0.18}Ti{sub 3-x}W{sub x}O{sub 12} (0 ≤ x ≤ 0.10) ceramics prepared by solid state reaction method have been investigated. X-ray diffraction (XRD) confirms the formation of single phase material with orthorhombic structure. A decrease in the lattice parameters and unit cell volume is observed with increasing W content. Strong UC luminescence at 527, 548 and 662 nm is seen under an excitation of 980 nm for an optimum W content (x = 0.06) and is attributed to the transitions {sup 2}H{sub 11/2} →{sup 4}I{sub 15/2}, {sup 4}S{sub 3/2} →{sup 4}I{sub 15/2} and {sup 4}F{sub 9/2} →{sup 4}I{sub 15/2} respectively. The improved UC luminescence is ascribed to the reduced defects such as oxygen vacancies and change in the crystal field around Er{sup 3+} ions due to B-site (Ti{sup 4+}) substitution with W{sup 6+} ions. Enhanced UC emission is observed for an optimum content of w{sup 6+} in the prepared composition Bi{sub 3.79}Er{sub 0.03}Yb{sub 0.18}Ti{sub 3-x}W{sub x}O{sub 12} for x = 0.06.

  4. Novel biotransformation process of podophyllotoxin to 4 β-sulfur-substituted podophyllum derivates with anti-tumor activity by Penicillium purpurogenum Y.J. Tang.

    Science.gov (United States)

    Bai, J-K; Zhao, W; Li, H-M; Tang, Y-J

    2012-01-01

    According to the structure-function relationship of podophyllotoxin (PTOX) and its analogue of 4'- demethylepipodophyllotoxin (DMEP), the 4 β-substitution of sulfur-containing heterocyclic compounds with a carbon-sulfur bond at 4 position of PTOX or DMEP is an essential modification direction for improving the anti-tumor activity. So, four novel 4 β-sulfursubstituted podophyllum derivatives (i.e., 4β -(1,2,4-triazole-3-yl)sulfanyl-4-deoxy-podophyllotoxin (4-MT-PTOX), 4β-(1,3,4- thiadiazole-2-yl)sulfanyl-4-deoxy-podophyllotoxin (4-MTD-PTOX), 4β-(1,2,4-triazole-3-yl)sulfanyl-4-deoxy-4' -demethylepipodophyllotoxin (4-MT-DMEP), and 4β-(1,3,4-thiadiazole-2-yl)sulfanyl-4-deoxy-4'-demethylepipodophyllotoxin (4-MTD-DMEP)) were designed and then successfully biosynthesized in this work. In the novel sulfur-substituted biotransformation processes, PTOX and DMEP was linked with sulfur-containing compounds (i.e., 3-mercapto-1,2,4-triazole (MT) and 2-mercapto-1,3,4-thiadiazole (MTD)) at 4 position of cycloparaffin to produce 4-MT-PTOX (1), 4-MTD-PTOX (2), 4-MT-DMEP (3), and 4-MTD-DMEP (4) by Penicillium purpurogenum Y.J. Tang, respectively, which was screened out from Diphylleia sinensis Li (Hubei, China). All the novel compounds exhibited promising in vitro bioactivity, especially 4-MT-PTOX (1). Compared with etoposide (i.e., a 50 % effective concentration [EC(50)] of 25.72, 167.97, and 1.15 M), the EC(50) values of 4-MT-PTOX (1) against tumor cell line BGC-823, A549 and HepG2 (i.e., 0.28, 0.76, and 0.42 M) were significantly improved by 91, 221 and 2.73 times, respectively. Moreover, the EC(50) value of 4-MT-PTOX (1) against the normal human cell line HK-2 (i.e., 182.4 μM) was 19 times higher than that of etoposide (i.e., 9.17 μM). Based on the rational design, four novel 4 β-sulfur-substituted podophyllum derivatives with superior in vitro anti-tumor activity were obtained for the first time. The correctness of structure-function relationship and rational drug

  5. Does the Al substitution in C–S–H(I) change its mechanical property?

    KAUST Repository

    Oh, Jae Eun; Clark, Simon M.; Monteiro, Paulo J.M.

    2011-01-01

    This study examines the influence of Al substitution for Si on the bulk modulus of calcium silicate hydrate I [C-S-H(I)], a structural analogue of C-S-H, by performing high-pressure synchrotron X-ray diffraction experiments in two C-S-H(I) samples: one a hydration product of alkali-activated slag and the other a synthetic C-S-H(I). The test result shows that not only the bulk modulus but also the incompressibility of the lattice parameters a, b, and c of two C-S-H(I) samples are very similar to each other, regardless of the Al substitution. This result may be due to the four-coordinated configuration of the substituted Al, which makes the dreierketten silicate chains maintain the same arrangement after the substitution. © 2010 Elsevier Ltd.

  6. Antimicrobial and antifungal activity of some (5-(adamantane-1-yl-4R-1,2,4-triazole-3-ylthiols substitutes

    Directory of Open Access Journals (Sweden)

    V. M. Odyntsova

    2016-12-01

    Full Text Available Lately adamantine containing substances have found wide use among the skeleton derivatives. The combination of adamantane and 1,2,4-triazole in one molecule creates significant preconditions to design new potential drugs with low toxicity and pronounced pharmacological activity. The aim of the research is the study of antimicrobial and antifungal activity of (5-(adamantane-1-yl-4-R-1,2,4-triazole-3-ylthiols substitutes. Materials and methods. Determination of antimicrobial and antifungal activity has been carried out by 2-fold serial dilutions method in liquid nutrient media. The substance of the antibacterial drug Trimethoprim has been applied as a control in determining antimicrobial activity of the compounds against the investigated strains of microorganisms. Results. According to the data of experiments the 5-(((5-(adamantane-1-yl-4-ethyl-4H-1,2,4-triazole-3-ylthiomethyl-4-ethyl-4H-1,2,4-triazole-3-thiol shows the same activity as Trimethoprim against P. aeruginosa (MIC is 62.5 µg/ml, MBC – 125 μg/ml, marked activity towards S. aureus (MIC is 15.6 μg/ml, MBC – 31.25 μg/ml while trimethoprim – 31.25 μg/ml, MBC – 62.5 µg/ml, greater fungistatic and fungicidal activity towards C. albicans, which amounted to 31.25 µg/ml, MFC – 62.5 µg/ml (while trimethoprim 62.5 µg/ml, MFC – 125 µg/ml. Reconstration of benzyldenhydrazide group to hydrazide one leads to the slight increase of bacteriostatic activity. Replacing the radical R from -Н to -C2H5 does not influence on the change of fungistatic activity. However, this resulted to the decrease in bacteriostatic activity against E. coli. The same is observed in relation to P. aeruginosa: from 62.5 μg/ml, MFC – 125 mcg/ml to 125 μg/ml, MFC – 125 µg/m respectively. Conclusion. The conducted study has showed that among the synthesized compounds there are some substances which strength of the antimicrobial and antifungal action in some cases exceeds the standard of comparison

  7. Sodium-carbonate co-substituted hydroxyapatite ceramics

    Directory of Open Access Journals (Sweden)

    Zoltan Z. Zyman

    2013-12-01

    Full Text Available Powders of sodium-carbonate co-substituted hydroxyapatite, having sodium content in the range of 0.25–1.5 wt.% with a 0.25 wt.% step, were prepared by a precipitation-solid state reaction route. Compacts of the powders were sintered in a CO2 flow (4 mL/min at 1100 °C for 2 h. The sintered ceramics contained sodium and carbonate ions in the ranges of 0–1.5 wt.% and 1.3–6 wt.%, respectively, which are typical impurity concentrations in biological apatite. A relationship between sodium and carbonate contents and the type of carbonate substitution was found. The total carbonate content progressively increased with the sodium content. The obtained ceramics showed an AB-type carbonate substitution. However, the substitution became more B-type as the sodium content increased. As a result, the carbonation was almost B-type (94 % for the highest sodium content (1.5 wt.%.

  8. Intermixing at the absorber-buffer layer interface in thin-film solar cells: The electronic effects of point defects in Cu(In,Ga)(Se,S){sub 2} and Cu{sub 2}ZnSn(Se,S){sub 4} devices

    Energy Technology Data Exchange (ETDEWEB)

    Varley, J. B.; Lordi, V. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

    2014-08-14

    We investigate point defects in the buffer layers CdS and ZnS that may arise from intermixing with Cu(In,Ga)(S,Se){sub 2} (CIGS) or Cu{sub 2}ZnSn(S,Se){sub 4} (CZTS) absorber layers in thin-film photovoltaics. Using hybrid functional calculations, we characterize the electrical and optical behavior of Cu, In, Ga, Se, Sn, Zn, Na, and K impurities in the buffer. We find that In and Ga substituted on the cation site act as shallow donors in CdS and tend to enhance the prevailing n-type conductivity at the interface facilitated by Cd incorporation in CIGS, whereas they are deep donors in ZnS and will be less effective dopants. Substitutional In and Ga can favorably form complexes with cation vacancies (A-centers) which may contribute to the “red kink” effect observed in some CIGS-based devices. For CZTS absorbers, we find that Zn and Sn defects substituting on the buffer cation site are electrically inactive in n-type buffers and will not supplement the donor doping at the interface as in CIGS/CdS or ZnS devices. Sn may also preferentially incorporate on the S site as a deep acceptor in n-type ZnS, which suggests possible concerns with absorber-related interfacial compensation in CZTS devices with ZnS-derived buffers. Cu, Na, and K impurities are found to all have the same qualitative behavior, most favorably acting as compensating acceptors when substituting on the cation site. Our results suggest one beneficial role of K and Na incorporation in CIGS or CZTS devices is the partial passivation of vacancy-related centers in CdS and ZnS buffers, rendering them less effective interfacial hole traps and recombination centers.

  9. Simple, heart-smart substitutions

    Science.gov (United States)

    Coronary artery disease - heart smart substitutions; Atherosclerosis - heart smart substitutions; Cholesterol - heart smart substitutions; Coronary heart disease - heart smart substitutions; Healthy diet - heart ...

  10. Cascade alkylarylation of substituted N-allylbenzamides for the construction of dihydroisoquinolin-1(2H-ones and isoquinoline-1,3(2H,4H-diones

    Directory of Open Access Journals (Sweden)

    Ping Qian

    2016-02-01

    Full Text Available An oxidative reaction for the synthesis of 4-alkyl-substituted dihydroisoquinolin-1(2H-ones with N-allylbenzamide derivatives as starting materials has been developed. The radical alkylarylation reaction proceeds through a sequence of alkylation and intramolecular cyclization. The substituent on the C–C double bond was found to play a key role for the progress of the reaction to give the expected products with good chemical yields. Additionally, N-methacryloylbenzamides were also suitable substrates for the current reaction and provided the alkyl-substituted isoquinoline-1,3(2H,4H-diones in good yield.

  11. World’s First Clinical Case of Gene-Activated Bone Substitute Application

    Directory of Open Access Journals (Sweden)

    I. Y. Bozo

    2016-01-01

    Full Text Available Treatment of patients with large bone defects is a complex clinical problem. We have initiated the first clinical study of a gene-activated bone substitute composed of the collagen-hydroxyapatite scaffold and plasmid DNA encoding vascular endothelial growth factor. The first patient with two nonunions of previously reconstructed mandible was enrolled into the study. Scar tissues were excised; bone defects (5–14 mm between the mandibular fragments and nonvascularized rib-bone autograft were filled in with the gene-activated bone substitute. No adverse events were observed during 12 months of follow-up. In 3 months, the average density of newly formed tissues within the implantation zone was 402.21 ± 84.40 and 447.68 ± 106.75 HU in the frontal and distal regions, respectively, which correlated with the density of spongy bone. Complete distal bone defect repair with vestibular and lingual cortical plates formation was observed in 6 and 12 months after surgery; thereby the posterior nonunion was successfully eliminated. However, there was partial resorption of the proximal edge of the autograft entailed to relapse of the anterior nonunion. Thus, the first clinical data on the safety and efficacy of the gene-activated bone substitute were obtained. Given a high complexity of the clinical situation the treatment, results might be considered as promising. NCT02293031.

  12. Inversion of substrate stereoselectivity of horse liver alcohol dehydrogenase by substitutions of Ser-48 and Phe-93

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Keehyuk; Plapp, Bryce V. (Iowa)

    2017-10-01

    The substrate specificities of alcohol dehydrogenases (ADH) are of continuing interest for understanding the physiological functions of these enzymes. Ser-48 and Phe-93 have been identified as important residues in the substrate binding sites of ADHs, but more comprehensive structural and kinetic studies are required. The S48T substitution in horse ADH1E has small effects on kinetic constants and catalytic efficiency (V/Km) with ethanol, but decreases activity with benzyl alcohol and affinity for 2,2,2-trifluoroethanol (TFE) and 2,3,4,5,6-pentafluorobenzyl alcohol (PFB). Nevertheless, atomic resolution crystal structures of the S48T enzyme complexed with NAD+ and TFE or PFB are very similar to the structures for the wild-type enzyme. (The S48A substitution greatly diminishes catalytic activity.) The F93A substitution significantly decreases catalytic efficiency (V/Km) for ethanol and acetaldehyde while increasing activity for larger secondary alcohols and the enantioselectivity for the R-isomer relative to the S-isomer of 2-alcohols. The doubly substituted S48T/F93A enzyme has kinetic constants for primary and secondary alcohols similar to those for the F93A enzyme, but the effect of the S48T substitution is to decrease V/Km for (S)-2-alcohols without changing V/Km for (R)-2-alcohols. Thus, the S48T/F93A substitutions invert the enantioselectivity for alcohol oxidation, increasing the R/S ratio by 10, 590, and 200-fold for 2-butanol, 2-octanol, and sec-phenethyl alcohol, respectively. Transient kinetic studies and simulations of the ordered bi bi mechanism for the oxidation of the 2-butanols by the S48T/F93A ADH show that the rate of hydride transfer is increased about 7-fold for both isomers (relative to wild-type enzyme) and that the inversion of enantioselectivity is due to more productive binding for (R)-2-butanol than for (S)-2-butanol in the ternary complex. Molecular modeling suggests that both of the sec-phenethyl alcohols could bind to the enzyme and that

  13. Inversion of substrate stereoselectivity of horse liver alcohol dehydrogenase by substitutions of Ser-48 and Phe-93.

    Science.gov (United States)

    Kim, Keehyuk; Plapp, Bryce V

    2017-10-01

    The substrate specificities of alcohol dehydrogenases (ADH) are of continuing interest for understanding the physiological functions of these enzymes. Ser-48 and Phe-93 have been identified as important residues in the substrate binding sites of ADHs, but more comprehensive structural and kinetic studies are required. The S48T substitution in horse ADH1E has small effects on kinetic constants and catalytic efficiency (V/K m ) with ethanol, but decreases activity with benzyl alcohol and affinity for 2,2,2-trifluoroethanol (TFE) and 2,3,4,5,6-pentafluorobenzyl alcohol (PFB). Nevertheless, atomic resolution crystal structures of the S48T enzyme complexed with NAD + and TFE or PFB are very similar to the structures for the wild-type enzyme. (The S48A substitution greatly diminishes catalytic activity.) The F93A substitution significantly decreases catalytic efficiency (V/K m ) for ethanol and acetaldehyde while increasing activity for larger secondary alcohols and the enantioselectivity for the R-isomer relative to the S-isomer of 2-alcohols. The doubly substituted S48T/F93A enzyme has kinetic constants for primary and secondary alcohols similar to those for the F93A enzyme, but the effect of the S48T substitution is to decrease V/K m for (S)-2-alcohols without changing V/K m for (R)-2-alcohols. Thus, the S48T/F93A substitutions invert the enantioselectivity for alcohol oxidation, increasing the R/S ratio by 10, 590, and 200-fold for 2-butanol, 2-octanol, and sec-phenethyl alcohol, respectively. Transient kinetic studies and simulations of the ordered bi bi mechanism for the oxidation of the 2-butanols by the S48T/F93A ADH show that the rate of hydride transfer is increased about 7-fold for both isomers (relative to wild-type enzyme) and that the inversion of enantioselectivity is due to more productive binding for (R)-2-butanol than for (S)-2-butanol in the ternary complex. Molecular modeling suggests that both of the sec-phenethyl alcohols could bind to the enzyme

  14. Technological substitution options for controlling greenhouse gas emissions

    International Nuclear Information System (INIS)

    Barbier, E.B.; Burgess, J.C.; Pearce, D.W.

    1991-01-01

    This chapter is concerned with technological options for greenhouse gas substitution. The authors interpret the term substitution to exclude energy conservation/efficiency measures, investments in afforestation (sinks), and greenhouse gas removal or abatement technologies. Their working definition of greenhouse gas substitution includes (1) replacement technologies, for example, substituting a greenhouse gas technology with a nongreenhouse gas technology; and (2) reduction technologies, for example, substituting a greenhouse gas technology with an alternative technology that reduces greenhouse gas emissions. Essentially, replacement technologies involve 100 percent reduction in CO 2 ; reduction technologies involve a partial reduction in CO 2 . Of the man-made sources of greenhouse gases, energy is the most important and is expected to contribute to at least half of the global warming effect in the near future. The majority of this impact is from fossil fuel combustion as a source of carbon dioxide (CO 2 ), although fossil fuels also contribute significantly to methane (CH 4 ), to nitrous oxide (N 2 O), and to low-level ozone (O 3 ) through production of various nitrogen gases (NO x ) and carbon monoxide (CO). This study analyzes the available greenhouse gas substitutions and their costs. The authors concentrate particularly on substitutions for fossil-fuel combustion and CFC production and consumption. They conclude by summarizing the potential for greenhouse gas substitution, the cost-effectiveness of the various options and the design of incentives for substitution

  15. Effect of Sr substituted La 2−x Sr x NiO 4+δ (x = 0, 0.2, 0.4, 0.6, and 0.8) on oxygen stoichiometry and oxygen transport properties

    KAUST Repository

    Inprasit, T.; Wongkasemjit, S.; Skinner, S. J.; Burriel, M.; Limthongkul, P.

    2015-01-01

    © The Royal Society of Chemistry 2015. Stoichiometry and oxygen diffusion properties of La2-xSrxNiO4±δ with x = 0.2, 0.4, 0.6, and 0.8 prepared via a sol-gel method were investigated in this study. Iodometric titration and thermogravimetric analysis were used to determine the oxygen non-stoichiometry. Over the entire compositional range, the samples exhibit oxygen hyperstoichiometry with the minimum value δ = 0.14 at x = 0.4. Mixed effects of reduction of oxygen excess and increasing valence of Ni were found to serve as charge compensation mechanisms; the former dominated at a low level of substitution, x < 0.4, while the latter dominated at higher levels of Sr (0.4 < x < 0.8). The highest oxygen diffusion coefficient was found for the minimum amount of Sr substitution, x = 0.2, continuously decreasing with x until x = 0.6. An unusual increase in D∗ was observed when the Sr content increased up to x = 0.8.

  16. (3S,4S)-3-Ethyl-4-hydroxy-3-(3-methoxyphenyl)-1-methylazepan-1-ium d-tartrate dihydrate

    OpenAIRE

    Zhui-Bai Qiu; Bo Chao; Xing-Hai Wang

    2008-01-01

    In the title compound, C16H26NO2+·C4H5O6−·2H2O, a meptazinol derivative, three C atoms of the azepane ring are disordered over two positions, with site-occupancy factors of 0.80 and 0.20; the major disorder component adopts a twist-chair conformation, while the minor component has a chair conformation. The benzene ring is axially substituted on the heterocyclic ring, resulting in a folded conformation of the cation. The absolute configuration was determined with reference to d...

  17. Thermophysical properties of Na2Th (MoO4)3 (s) and Na4Th (MoO4)4 (s)

    International Nuclear Information System (INIS)

    Dash, Smruti; Rakshit, S.K.; Singh, Ziley; Keskar, Meera; Dahale, N.D.

    2009-01-01

    The heat capacity of Na 2 Th (MoO 4 ) 3 (s) and Na 4 Th (MoO 4 ) 4 (s) have been measured by differential scanning calorimeter in the temperature range 318 to 845 K. The corresponding values are: C p,m (Na 2 Th (MoO 4 ) 3 ,s,T) (JK-1 mol-1) 368.710+ 1.0 10-1 (T/K) - 4950267 (K/T)2 (318 ≤ T (K) ≤ 845). C p,m (Na 4 Th (MoO 4 ) 4 ,s,T) (JK-1 mol-1) = 638.761+ 5.12 10-3 (T/K) - 12691691 (K/T)-2 (318 ≤ T (K) ≤ 845). Experimental heat capacity values for Na 2 Th (MoO 4 ) 3 (s) match reasonably well with that of additive oxide values. But C p,m (T) values of Na 4 Th (MoO 4 ) 4 (s) deviates substantially from the additive oxide values above 700 K. The uncertainty of the measurements reported in this study is calculated to be within 1 to 3 % . (author)

  18. Substitute energy resource policy in Japan

    International Nuclear Information System (INIS)

    Umehara, Katsuhiko

    1980-01-01

    Japan depends 88% of energy resources and 99.8% of petroleum on imports. The solution of energy problems is now made internationally. As the means for Japan, there are the substitution of other resources for petroleum and its promotion. However, this involves the considerable funds for the development and utilization, which must be borne by the people in the form of tax. For governmental financing, a special account must be set up for the particular purpose. In the research and development of new energy resources, new institution is required. The following matters are described: petroleum shortage coming even in 1980s, the international need of substitute energy development, the need for establishing measures for substitute energy resources, acquisition of the funds, special-account governmental financing, and an institute of new energy development. (author)

  19. Orthogonal 4,10 and 6,12 substitution of dibenzo[def,mno]chrysene polycyclic aromatic small molecules

    KAUST Repository

    Koldemir, Unsal; Tinkham, Jonathan S.; Johnson, Robert; Lim, Bogyu; Yemam, Henok A.; Gagnon, Kevin J.; Parkin, Sean; Sellinger, Alan

    2017-01-01

    A series of new polycyclic aromatic hydrocarbon compounds based on (4,10-disubstituted-dibenzo[def,mno]chrysene-6,12-dione) and 4,10 di-substituted 6,12-bis(triisopropylsilylethynyl)dibenzo[def,mno]chrysene are reported with tunable electronic properties through varied molecular architecture. Starting with an inexpensive commercially available textile dye known as Vat Orange #3, (4,10-dibromo-dibenzo[def,mno] chrysene-6,12-dione) we extended the conjugation at the 4- and 10-positions by the attachment of both electron rich and deficient hexylvinylphthalimide, thiophene, hexylthiophene, triphenylamine, and hexylbithiophene aromatic groups, and studied the resultant optoelectronic properties. By applying various synthetic metal-catalyzed reactions, soluble dibenzo[def,mno]chrysene and dibenzo[def,mno]chrysene-6,12-dione derivatives were achieved with optical edge band gaps between 2.30 eV and 1.65 eV.

  20. Orthogonal 4,10 and 6,12 substitution of dibenzo[def,mno]chrysene polycyclic aromatic small molecules

    KAUST Repository

    Koldemir, Unsal

    2017-07-14

    A series of new polycyclic aromatic hydrocarbon compounds based on (4,10-disubstituted-dibenzo[def,mno]chrysene-6,12-dione) and 4,10 di-substituted 6,12-bis(triisopropylsilylethynyl)dibenzo[def,mno]chrysene are reported with tunable electronic properties through varied molecular architecture. Starting with an inexpensive commercially available textile dye known as Vat Orange #3, (4,10-dibromo-dibenzo[def,mno] chrysene-6,12-dione) we extended the conjugation at the 4- and 10-positions by the attachment of both electron rich and deficient hexylvinylphthalimide, thiophene, hexylthiophene, triphenylamine, and hexylbithiophene aromatic groups, and studied the resultant optoelectronic properties. By applying various synthetic metal-catalyzed reactions, soluble dibenzo[def,mno]chrysene and dibenzo[def,mno]chrysene-6,12-dione derivatives were achieved with optical edge band gaps between 2.30 eV and 1.65 eV.

  1. Heterocycles [h]-Fused Onto 4-Oxoquinoline-3-Carboxylic Acid, Part VIII [1]. Convenient Synthesis and Antimicrobial Properties of Substituted Hexahydro[1,4]diazepino[2,3-h]quinoline-9-carboxylic acid and Its Tetrahydroquino[7,8-b]benzodiazepine Analog

    Directory of Open Access Journals (Sweden)

    Yusuf M. Al-Hiari

    2008-11-01

    Full Text Available [1,4]Diazepino[2,3-h]quinolone carboxylic acid 3 and its benzo-homolog tetrahydroquino[7,8-b]benzodiazepine-3-carboxylic acid 5 were prepared via PPAcatalyzed thermal lactamization of the respective 8-amino-7-substituted-1,4-dihydroquinoline-3-carboxylic acid derivatives 8, 10. The latter compounds were obtained by reduction of their 8-nitro-7-substituted-1,4-dihydroquinoline-3-carboxylic acid precursors 7, 9 which, in turn, were prepared by reaction of 7-chloro-1-cyclopropyl-6-fluoro-8-nitro-1,4-dihydroquinoline-3-carboxylic acid (6 with each of β-alanine and anthranilic acid. All intermediates and target compounds were characterized using elemental analysis, NMR, IR and MS spectral data. The prepared targets and the intermediates have shown interesting antibacterial activity mainly against Gram positive strains. In particular, compound 8 showed good activity against S. aureus (MIC = 0.39 μg/mL and B. subtilis (MIC = 0.78 μg/mL. Compounds 5a and 9 have also displayed good antifungal activity against C. albicans (MIC = 1.56 μg/mL and 0.78 μg/mL, respectively. None of the compounds tested showed any anticancer activity against solid breast cancer cell line MCF-7 cells or a human breast adenocarcinoma cell line.

  2. Synthesis of novel 4,6-di(substituted)amino-1,2-dihydro-1,3,5-triazine derivatives as topical antiseptic agents.

    Science.gov (United States)

    Maeda, Shirou; Kita, Toshiko; Meguro, Kanji

    2009-02-12

    A series of novel 4,6-di(substituted)amino-1,2-dihydro-1,3,5-triazine derivatives designed to have ClogP of 5.1-7.5 was synthesized and evaluated for their antiseptic properties by MIC and MBC tests against Gram-positive and Gram-negative bacteria, including MRSA, VRE, and P. aeruginosa. Among these compounds, 4-alkyl-6-aralkyl derivatives having ClogP of 6.6-7.1 and 4-alkyl-6-aryl or 4,6-dialkyl derivatives with ClogP of 6.0-6.4 showed pronounced antibacterial activities in both tests.

  3. Structure-activity relationship of daptomycin analogues with substitution at (2S, 3R) 3-methyl glutamic acid position.

    Science.gov (United States)

    Lin, Du'an; Lam, Hiu Yung; Han, Wenbo; Cotroneo, Nicole; Pandya, Bhaumik A; Li, Xuechen

    2017-02-01

    Daptomycin is a highly effective lipopeptide antibiotic against Gram-positive pathogens. The presence of (2S, 3R) 3-methyl glutamic acid (mGlu) in daptomycin has been found to be important to the antibacterial activity. However the role of (2S, 3R) mGlu is yet to be revealed. Herein, we reported the syntheses of three daptomycin analogues with (2S, 3R) mGlu substituted by (2S, 3R) methyl glutamine (mGln), dimethyl glutamic acid and (2S, 3R) ethyl glutamic acid (eGlu), respectively, and their antibacterial activities. The detailed synthesis of dimethyl glutamic acid was also reported. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Bisphenol S and F: A Systematic Review and Comparison of the Hormonal Activity of Bisphenol A Substitutes

    Science.gov (United States)

    Bolden, Ashley L.

    2015-01-01

    Background Increasing concern over bisphenol A (BPA) as an endocrine-disrupting chemical and its possible effects on human health have prompted the removal of BPA from consumer products, often labeled “BPA-free.” Some of the chemical replacements, however, are also bisphenols and may have similar physiological effects in organisms. Bisphenol S (BPS) and bisphenol F (BPF) are two such BPA substitutes. Objectives This review was carried out to evaluate the physiological effects and endocrine activities of the BPA substitutes BPS and BPF. Further, we compared the hormonal potency of BPS and BPF to that of BPA. Methods We conducted a systematic review based on the Office of Health Assessment and Translation (OHAT) protocol. Results We identified the body of literature to date, consisting of 32 studies (25 in vitro only, and 7 in vivo). The majority of these studies examined the hormonal activities of BPS and BPF and found their potency to be in the same order of magnitude and of similar action as BPA (estrogenic, antiestrogenic, androgenic, and antiandrogenic) in vitro and in vivo. BPS also has potencies similar to that of estradiol in membrane-mediated pathways, which are important for cellular actions such as proliferation, differentiation, and death. BPS and BPF also showed other effects in vitro and in vivo, such as altered organ weights, reproductive end points, and enzyme expression. Conclusions Based on the current literature, BPS and BPF are as hormonally active as BPA, and they have endocrine-disrupting effects. Citation Rochester JR, Bolden AL. 2015. Bisphenol S and F: a systematic review and comparison of the hormonal activity of bisphenol A substitutes. Environ Health Perspect 123:643–650; http://dx.doi.org/10.1289/ehp.1408989 PMID:25775505

  5. Synthesis, Leishmanicidal Activity and Theoretical Evaluations of a Series of Substituted bis-2-Hydroxy-1,4-Naphthoquinones

    Directory of Open Access Journals (Sweden)

    Morgana V. de Araújo

    2014-09-01

    Full Text Available A series of eight substituted bis-2-hydroxy-1,4-naphthoquinone derivatives was synthesized through lawsone condensation with various aromatic and aliphatic aldehydes under mild acidic conditions. The title compounds were evaluated for antileishmanial activity in vitro against Leishmania amazonensis and Leishmania braziliensis promastigotes; six compounds showed good activity without significant toxic effects. The compound with the highest activity was used for an in vivo assay with Leishmania amazonensis.

  6. Structural, Transport and Electrochemical Properties of LiFePO4 Substituted in Lithium and Iron Sublattices (Al, Zr, W, Mn, Co and Ni)

    Science.gov (United States)

    Molenda, Janina; Kulka, Andrzej; Milewska, Anna; Zając, Wojciech; Świerczek, Konrad

    2013-01-01

    LiFePO4 is considered to be one of the most promising cathode materials for lithium ion batteries for electric vehicle (EV) application. However, there are still a number of unsolved issues regarding the influence of Li and Fe-site substitution on the physicochemical properties of LiFePO4. This is a review-type article, presenting results of our group, related to the possibility of the chemical modification of phosphoolivine by introduction of cation dopants in Li and Fe sublattices. Along with a synthetic review of previous papers, a large number of new results are included. The possibility of substitution of Li+ by Al3+, Zr4+, W6+ and its influence on the physicochemical properties of LiFePO4 was investigated by means of XRD, SEM/EDS, electrical conductivity and Seebeck coefficient measurements. The range of solid solution formation in Li1−3xAlxFePO4, Li1−4xZrxFePO4 and Li1−6xWxFePO4 materials was found to be very narrow. Transport properties of the synthesized materials were found to be rather weakly dependent on the chemical composition. The battery performance of selected olivines was tested by cyclic voltammetry (CV). In the case of LiFe1−yMyPO4 (M = Mn, Co and Ni), solid solution formation was observed over a large range of y (0 0.25 leads to considerably lower values of σ. The activated character of electrical conductivity with a rather weak temperature dependence of the Seebeck coefficient suggests a small polaron-type conduction mechanism. The electrochemical properties of LiFe1−yMyPO4 strongly depend on the Fe substitution level. PMID:28809235

  7. Structural, Transport and Electrochemical Properties of LiFePO4 Substituted in Lithium and Iron Sublattices (Al, Zr, W, Mn, Co and Ni

    Directory of Open Access Journals (Sweden)

    Konrad Świerczek

    2013-04-01

    Full Text Available LiFePO4 is considered to be one of the most promising cathode materials for lithium ion batteries for electric vehicle (EV application. However, there are still a number of unsolved issues regarding the influence of Li and Fe-site substitution on the physicochemical properties of LiFePO4. This is a review-type article, presenting results of our group, related to the possibility of the chemical modification of phosphoolivine by introduction of cation dopants in Li and Fe sublattices. Along with a synthetic review of previous papers, a large number of new results are included. The possibility of substitution of Li+ by Al3+, Zr4+, W6+ and its influence on the physicochemical properties of LiFePO4 was investigated by means of XRD, SEM/EDS, electrical conductivity and Seebeck coefficient measurements. The range of solid solution formation in Li1−3xAlxFePO4, Li1−4xZrxFePO4 and Li1−6xWxFePO4 materials was found to be very narrow. Transport properties of the synthesized materials were found to be rather weakly dependent on the chemical composition. The battery performance of selected olivines was tested by cyclic voltammetry (CV. In the case of LiFe1−yMyPO4 (M = Mn, Co and Ni, solid solution formation was observed over a large range of y (0 0.25 leads to considerably lower values of σ. The activated character of electrical conductivity with a rather weak temperature dependence of the Seebeck coefficient suggests a small polaron-type conduction mechanism. The electrochemical properties of LiFe1−yMyPO4 strongly depend on the Fe substitution level.

  8. Nightmare on Shaw Street: Getting Lost in Shorty’s Private Collection

    OpenAIRE

    Emily Bullock

    2012-01-01

    This article discusses the semiotic and affective affordances of a regional museum on the west coast of Australia’s only island state, Tasmania. Shorty’s Private Collection is a small museum displaying items collected from around the region, with a focus on resuscitated mining materials. The owner also creates figures derived from popular culture from these items. The article uses the methodology of creative non-fiction in order to situate the museum within the marginal community ...

  9. Zeolite - a possible substitute of silica gel in spectrophotometric determination of uranium?

    International Nuclear Information System (INIS)

    Foeldesova, M; Dillinger, P.

    2006-01-01

    Zeolites sorption abilities differ from the ones of the silica gel, which is normally used for uranium determination by spectrophotometric method. The difference is obvious mainly in the case of zeolites chemically modified with 1 or 2 mol/L NaOH solution. Absorbances measured using these zeolites on an radioactive water samples were 4 to 4.2 times bigger than the ones with silica gel. This avoids a use of one universal calibration curve for experimental data evaluation. Within delivered experimental data only a calibration curve for silica gel was provided. Its application to zeolites caused substantial misinterpretation of the results. Calculational construction of individual calibration curves made at this work shaw, that zeolites have a potential to replace the silica gel. This possibility is necessary to confirm by more experiments. Better sorption abilities of the modified zeolites would be utilized to reduce the lower limit for uranium determination by spectrophotometric method. (authors)

  10. Synthesis of 4-substituted and 6-substituted 4-En-3-ketosteroids to be used in radioimmunoassays of testosterone and progesterone

    International Nuclear Information System (INIS)

    Handschuh, D.

    1983-01-01

    The synthetic antigens required for the development of a specific radioimmunoassay for steroids are obtained, if derivatives of steroid carboxylic acid are bound to the lysin residues of bovine serum albumin. In this study, the carboxyl groups were introduced into the steroid in positions C4 or C6. For this purpose the 4-en-3-ketosteroids, progesterone and testosterone, were functionalised in C6, which is an allylic C atom. One or two further steps were required for the formation of the carboxyl acid derivatives, which then replaced the above-mentioned atoms C4 and C6. Described are the synthesis of 4-S-mercaptopropionic acid derivatives of progesterone and testosterone using 2-step or 4-step reaction procedures as well as alternative methods of synthetising different derivatives of 6-methylidene carboxyl acid. In order to characterise the products obtained measurements were carried out on the basis of 1 H-NMR, 13 C-NMR, IR spectra, CD and mass spectroscopy. (orig./RB) [de

  11. Pathogenic substitution of IVS15 + 5G > A in SLC26A4 in patients of Okinawa Islands with enlarged vestibular aqueduct syndrome or Pendred syndrome.

    Science.gov (United States)

    Ganaha, Akira; Kaname, Tadashi; Yanagi, Kumiko; Naritomi, Kenji; Tono, Tetsuya; Usami, Shin-ichi; Suzuki, Mikio

    2013-05-24

    Pendred syndrome (PS) and nonsyndromic hearing loss associated with enlarged vestibular aqueduct (EVA) are caused by SLC26A4 mutations. The Okinawa Islands are the southwestern-most islands of the Japanese archipelago. And ancestral differences have been reported between people from Okinawa Island and those from the main islands of Japan. To confirm the ethnic variation of the spectrum of SLC26A4 mutations, we investigated the frequencies of SLC26A4 mutations and clinical manifestations of patients with EVA or PS living in the Okinawa Islands. We examined 22 patients with EVA or PS from 21 unrelated families in Okinawa Islands. The patient's clinical history, findings of physical and otoscopic examinations, hearing test, and computed tomography (CT) scan of the temporal bones were recorded. To detect mutations, all 21 exons and the exon-intron junctions of SLC26A4 were sequenced for all subjects. Quantitative reverse-transcription polymerase chain reaction (qRT-PCR) for SLC26A4 and calculations using the comparative CT (2(-ΔΔCT)) method were used to determine the pathogenicity associated with gene substitutions. SLC26A4 mutations were identified in 21 of the 22 patients. We found a compound heterozygous mutation for IVS15 + 5G > A/H723R in nine patients (41%), a homozygous substitution of IVS15 + 5G > A in six patients (27%), and homozygous mutation for H723R in five patients (23%). The most prevalent types of SLC26A4 alleles were IVS15 + 5G > A and H723R, which both accounted for 15/22 (68%) of the patients. There were no significant correlations between the types of SLC26A4 mutation and clinical manifestations. Based on qRT-PCR results, expression of SLC26A4 was not identified in patients with the homozygous substitution of IVS15 + 5G > A. The substitution of IVS15 + 5G > A in SLC26A4 was the most common mutation in uniquely found in patients with PS and EVA in Okinawa Islands. This suggested that the spectrum of SLC26A4 mutation differed

  12. Growth of fingers at an unstable diffusing interface in a porous medium or hele-shaw cell

    Energy Technology Data Exchange (ETDEWEB)

    Wooding, R A

    1969-11-27

    Waves at an unstable horizontal interface, between 2 fluids moving vertically through a saturated porous medium, are observed to grow rapidly to become fingers (i.e., the amplitude greatly exceeds the wavelength). For a diffusing interface, in experiments using a Hele-Shaw cell, the mean amplitude taken over many fingers grows approx. as (time)U2D, followed by a transition to a growth proportional to time. Correspondingly, the mean wave number decreases approx. as (time)U-1/2D. Because of the rapid increase in amplitude, longitudinal dispersion ultimately becomes negligible relative to wave growth. To represent the observed quantities at large time, the transport equation is suitably weighted and averaged over the horizontal plane. Hyperbolic equations result, and the ascending and descending zones containing the fronts of the fingers are replaced by discontinuities. These averaged equations form an open set, but closure is achieved by assuming a law for the mean wave number based on similarity. (22 refs.)

  13. 2-Bromo-1,4-naphthoquinone: a potentially improved substitute of menadione in Apatone™ therapy

    Directory of Open Access Journals (Sweden)

    F.S. Graciani

    2012-08-01

    Full Text Available Apatone™, a combination of menadione (2-methyl-1,4-naphthoquinone, VK3 and ascorbic acid (vitamin C, VC is a new strategy for cancer treatment. Part of its effect on tumor cells is related to the cellular pro-oxidative imbalance provoked by the generation of hydrogen peroxide (H2O2 through naphthoquinone redox cycling. In this study, we attempted to find new naphthoquinone derivatives that would increase the efficiency of H2O2 production, thereby potentially increasing its efficacy for cancer treatment. The presence of an electron-withdrawing group in the naphthoquinone moiety had a direct effect on the efficiency of H2O2 production. The compound 2-bromo-1,4-naphthoquinone (BrQ, in which the bromine atom substituted the methyl group in VK3, was approximately 10- and 19-fold more efficient than VK3 in terms of oxygen consumption and H2O2 production, respectively. The ratio [H2O2]produced / [naphthoquinone]consumed was 68 ± 11 and 5.8 ± 0.2 (µM/µM for BrQ and VK3, respectively, indicating a higher efficacy of BrQ as a catalyst for the autoxidation of ascorbic acid. Both VK3 and BrQ reacted with glutathione (GSH, but BrQ was the more effective substrate. Part of GSH was incorporated into the naphthoquinone, producing a nucleophilic substitution product (Q-SG. The depletion of BrQ by GSH did not prevent its redox capacity since Q-SG was also able to catalyze the production of reactive oxygen species. VK3/VC has already been submitted to clinical trials for the treatment of prostate cancer and has demonstrated promising results. However, replacement of VK3 with BrQ will open new lines of investigation regarding this approach to cancer treatment.

  14. 2-Bromo-1,4-naphthoquinone: a potentially improved substitute of menadione in Apatone™ therapy

    International Nuclear Information System (INIS)

    Graciani, F.S.; Ximenes, V.F.

    2012-01-01

    Apatone™, a combination of menadione (2-methyl-1,4-naphthoquinone, VK 3 ) and ascorbic acid (vitamin C, VC) is a new strategy for cancer treatment. Part of its effect on tumor cells is related to the cellular pro-oxidative imbalance provoked by the generation of hydrogen peroxide (H 2 O 2 ) through naphthoquinone redox cycling. In this study, we attempted to find new naphthoquinone derivatives that would increase the efficiency of H 2 O 2 production, thereby potentially increasing its efficacy for cancer treatment. The presence of an electron-withdrawing group in the naphthoquinone moiety had a direct effect on the efficiency of H 2 O 2 production. The compound 2-bromo-1,4-naphthoquinone (BrQ), in which the bromine atom substituted the methyl group in VK 3 , was approximately 10- and 19-fold more efficient than VK 3 in terms of oxygen consumption and H 2 O 2 production, respectively. The ratio [H 2 O 2 ] produced / [naphthoquinone] consumed was 68 ± 11 and 5.8 ± 0.2 (µM/µM) for BrQ and VK 3 , respectively, indicating a higher efficacy of BrQ as a catalyst for the autoxidation of ascorbic acid. Both VK 3 and BrQ reacted with glutathione (GSH), but BrQ was the more effective substrate. Part of GSH was incorporated into the naphthoquinone, producing a nucleophilic substitution product (Q-SG). The depletion of BrQ by GSH did not prevent its redox capacity since Q-SG was also able to catalyze the production of reactive oxygen species. VK 3 /VC has already been submitted to clinical trials for the treatment of prostate cancer and has demonstrated promising results. However, replacement of VK 3 with BrQ will open new lines of investigation regarding this approach to cancer treatment

  15. Electrical conductivity of cobalt–titanium substituted SrCaM hexaferrites

    International Nuclear Information System (INIS)

    Eraky, M.R.

    2012-01-01

    A series of polycrystalline M-type hexagonal ferrites with the composition Sr 0.5 Ca 0.5 Co x Ti x Fe 12−2x O 19 (where x=0.0–0.8) were prepared by the conventional ceramic technique. The electrical conductivity has been measured from 300 to 590 K. The dc conductivity, σ dc , exhibited a semiconductor behavior. The negative sign of thermoelectric power coefficient S reveals that all samples are n-type semiconductors. Both σ dc and mobility, μ d , increases with the substitution of Co 2+ and Ti 4+ ions, reach maximum at x=0.4 and start decreasing at x>0.4. Many conduction mechanisms were discussed to explain the electric conduction in the system. It was found that the hopping conduction is the predominant conduction mechanism. For samples with compositional parameter x=0.0 and 0.8, the band conduction mechanism shares in electric conduction beside the hopping process. - Highlights: ► SrCaCoTiM hexaferrites have been prepared by conventional ceramic technique. ► The electrical conductivity exhibited a semiconductor behavior. There is an increase in conductivity up to x=0.4 for Co and Ti substitution. ► The hopping conduction is the predominant conduction mechanism.

  16. Associations between generic substitution and patient-related factors

    DEFF Research Database (Denmark)

    Østergaard Rathe, Jette

    Associations between generic substitution and patient-related factors Jette Østergaard Rathe1, Pia V. Larsen1, Morten Andersen2, Janus L. Thomsen3, Maja S. Paulsen1, Jens Søndergaard1 1. Research Unit of General Practice, Institute of Public Health, University of Southern Denmark 2. Centre...... for Pharmacoepidemiology, Karolinska Institutet, Department of Medicine Solna, Stockholm, Sweden 3. Danish Quality Unit of General Practice, Odense, Denmark Background Generic substitution means that chemically equivalent but less expensive drugs are dispensed in place of a brand name product. Although generic medicines...... by definition are bioequivalent to their brand name counterparts there are concerns about whether generic substitution is always accompanied by clinical equivalence in terms of effectiveness and that it may cause concerns and thereby causing some skepticism towards generic substitution. There is, however...

  17. Study of Substituted Ester Formation in Red Wine by the Development of a New Method for Quantitative Determination and Enantiomeric Separation of Their Corresponding Acids.

    Science.gov (United States)

    Lytra, Georgia; Franc, Celine; Cameleyre, Margaux; Barbe, Jean-Christophe

    2017-06-21

    A new method was developed for quantifying substituted acids including, where applicable, their various unexplored enantiomeric forms. A new step was added to acids' usual quantification methods, consisting of extraction, derivatization to methyl esters, and gas chromatography analysis: preliminary extraction was performed at basic pH to eliminate ethyl esters, thus avoiding their transesterification during derivatization. Quantitation and enantiomeric distribution of some substituted esters and their corresponding acids were established in 31 commercial Bordeaux red wines from 0 to 20 years old. A strong positive correlation was observed between the age of wine and levels of ethyl 2-methylpropanoate, ethyl 3-methylbutanoate, ethyl 2-methylbutanoate, ethyl (3R)-3-hydroxybutanoate, both enantiomeric forms of ethyl 2-hydroxy-3-methylbutanoate, and ethyl (2S)-2-hydroxy-4-methylpentanoate, but not ethyl (3S)-3-hydroxybutanoate. However, the standard deviations of average concentrations for the corresponding substituted acids were so large that only few correlations between concentrations and age were observed. Concentrations of (2S)-2-hydroxy-3-methylbutanoic acid and (2S)-2-hydroxy-4-methylpentanoic acid increased slightly over time, while (2R)-2-hydroxy-4-methylpentanoic acid levels decreased slightly with the age. Variations in the ratio of substituted ethyl esters to their corresponding acids over time detected thanks to these analytical advances suggested that, in general, acids were continuously esterified during aging.

  18. Experimental Determination of Activation Energy of Nucleophilic Aromatic Substitution on Porphyrins

    Science.gov (United States)

    Rizvi, Waqar; Khwaja, Emaad; Siddiqui, Saim; Bhupathiraju, N. V. S. Dinesh K.; Drain, Charles Michael

    2018-01-01

    A physical organic chemistry experiment is described for second-year college students. Students performed nucleophilic aromatic substitution (NAS) reactions on 5,10,15,20-tetrakis(2,3,4,5,6-pentafluorophenyl)porphyrin (TPPF[subscript 20]) using three different nucleophiles. Substitution occurs preferentially at the 4-position ("para")…

  19. Microwave Palaeointensity Experiments On Terrestrial and Martian Material

    Science.gov (United States)

    Shaw, J.; Hill, M.; Gratton, M.

    The microwave palaeointensity technique was developed in Liverpool University (Walton et al 1996) and has successfully been applied to archaeological ceramics and recent lavas (Shaw et al 1996, 1999.; Hill et al 1999,2000). These published results show that microwave analysis provides accurate palaeointensity determinations com- bined with a very high success rate. Most recently the technique has been successfully applied to Martian material (Shaw et al, 2001) to look for the existence of an internal Martian dynamo early in Martian history. New experiments have been carried out us- ing microwaves to demagnetise synthetic muti-component TRM's and new palaeoin- tensity experiments providing a comparison between microwave analysis of laboratory TRM's and conventional thermal Thellier analysis of microwave generated mTRM's. These experiments demonstrate the equivalence of microwave and thermally gener- ated TRM's. D. Walton, S Snape, T.C. Rolph, J. Shaw and J.A. Share, Application of ferromagnetic resonance heating to palaeointensity determinations.1996, Phys Earth Planet Int,94, 183-186. J. Shaw, D. Walton, S Yang, T.C.Rolph, and J.A. Share. Microwave Archaeointensities from Peruvian Ceramics. 1996, Geophys. J. Int,124,241-244 J. Shaw, S. Yang, T. C. Rolph, and F. Y. Sun. A comparison of archaeointensity results from Chinese ceramics using Microwave and conventional ThellierSs and ShawSs methods.,1999, G J Int.136, 714-718 M. Hill, and J. Shaw, 1999, Palaeointensity results for Historic Lavas from Mt. Etna using microwave demagnetisation/remagnetisation in a modified Thellier type exper- iment. G. J. Int, 139, 583-590 M. J. Hill, and J. Shaw, 2000. Magnetic field intensity study of the 1960 Kilauea lava flow, Hawaii, using the microwave palaeointensity technique, Geophys. J. Int., 142, 487-504. J. Shaw, M. Hill, and S. J. Openshaw, 2001, Investigating the ancient Martian magnetic field using microwaves, Earth and Planetary Science Letters 190 (2001) 103-109

  20. Palladium-Catalyzed Asymmetric Allylic Alkylation of 4-Substituted Isoxazolidin-5-ones: Straightforward Access to β2,2 -Amino Acids.

    Science.gov (United States)

    Nascimento de Oliveira, Marllon; Arseniyadis, Stellios; Cossy, Janine

    2018-04-03

    We report here an unprecedented and highly enantioselective palladium-catalyzed allylic alkylation applied to 4-substituted isoxazolidin-5-ones. Ultimately, the process provides a straightforward access to β 2,2 -amino acids bearing an all-carbon quaternary stereogenic center in great yields and a high degree of enantioselectivity. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Structure, stability, and thermomechanical properties of Ca-substituted Pr2NiO4 + δ

    Science.gov (United States)

    Pikalova, E. Yu.; Medvedev, D. A.; Khasanov, A. F.

    2017-04-01

    Ca-substituted layered nickelates with a general Pr2- x Ca x NiO4 + δ composition ( x = 0-0.7, Δ x = 0.1) were prepared in the present work and their structural and physic-chemical properties were investigated in order to select the most optimal materials, which can be used as cathodes for solid oxide fuel cells. With an increase in Ca content in Pr2- x Ca x NiO4 + δ the following tendencies were observed: (i) a decrease in the concentration of nonstoichiometric oxygen (δ), (ii) a decrease in the unit cell parameters and volume, (iii) stabilization of the tetragonal structure, (iv) a decrease of the thermal expansion coefficients, and (v) enchancement of thermodynamic stability and compatibility with selected oxygen- and proton-conducting electrolytes. The Pr1.9Ca0.1NiO4 + δ material, having highest δ value, departs from the general "properties-composition" dependences ascertained. This indicates that oxygen non-stoichiometry has determining influence on the functional properties of layered nickelates.

  2. DFT, FT-IR, FT-Raman and NMR studies of 4-(substituted phenylazo)-3,5-diacetamido-1H-pyrazoles

    Science.gov (United States)

    Kınalı, Selin; Demirci, Serkan; Çalışır, Zühre; Kurt, Mustafa; Ataç, Ahmet

    2011-05-01

    We present a detailed analysis of the structural and vibrational spectra of some novel azo dyes. 2-(Substituted phenylazo)malononitriles were synthesized by the coupling reaction of the diazonium salts, which were prepared with the use of various aniline derivatives with malononitrile, and then 4-(substituted phenylazo)-3,5-diamino-1H-pyrazole azo dyes were obtained via the ring closure of the azo compounds with hydrazine monohydrate. The experimental and theoretical vibrational spectra of azo dyes were studied. The structural and spectroscopic analysis of the molecules were carried out by using Becke's three-parameters hybrid functional (B3LYP) and density functional harmonic calculations. The 1H nuclear magnetic resonance (NMR) chemical shifts of the azo dye molecules were calculated using the gauge-invariant-atomic orbital (GIAO) method. The calculated vibrational wavenumbers and chemical shifts were compared with the experimental data of the molecules.

  3. In vitro biological performance of minerals substituted hydroxyapatite coating by pulsed electrodeposition method

    Energy Technology Data Exchange (ETDEWEB)

    Gopi, Dhanaraj, E-mail: dhanaraj_gopi@yahoo.com [Department of Chemistry, Periyar University, Salem 636 011, Tamilnadu (India); Centre for Nanoscience and Nanotechnology, Periyar University, Salem 636 011, Tamilnadu (India); Karthika, Arumugam; Nithiya, Subramani [Department of Chemistry, Periyar University, Salem 636 011, Tamilnadu (India); Kavitha, Louis [Centre for Nanoscience and Nanotechnology, Periyar University, Salem 636 011, Tamilnadu (India); Department of Physics, Periyar University, Salem 636 011, Tamilnadu (India)

    2014-03-01

    The present study deals with the optimization of minerals (Sr, Mg and Zn) substituted hydroxyapatite coatings (M-HAP) at different pulse on and off time (1 s, 2 s, 3 s and 4 s) by pulsed electrodeposition method. The formation of M-HAP coating was investigated using Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction studies (XRD). The morphological features and the content of Sr, Mg and Zn ions in M-HAP coated Ti–6Al–4V were investigated by high resolution scanning electron microscopy (HRSEM) and energy dispersive X-ray analysis (EDAX). The electrochemical studies were performed for M-HAP coated Ti–6Al–4V in simulated body fluid which exhibited better corrosion resistance at the prolonged pulse off time. The in vitro cell adhesion test revealed that the M-HAP coating is found appropriate for the formation of new cell growth which proves the enhanced biocompatible nature of the coating. Thus the M-HAP coating will serve as a potential candidate in orthopedic applications. - Highlights: • We successfully achieved minerals substituted HAP coatings on Ti alloy by PED method. • The M-HAP coated Ti alloy exhibited better bioresistivity in SBF. • The as-coated sample showed antimicrobial activity and better cell viability. • The in vitro test displayed the formation of new cell growth. • The M-HAP coating can serve as a better candidate in orthopedic applications.

  4. Si-substituted hydroxyapatite nanopowders: Synthesis, thermal stability and sinterability

    International Nuclear Information System (INIS)

    Bianco, Alessandra; Cacciotti, Ilaria; Lombardi, Mariangela; Montanaro, Laura

    2009-01-01

    Synthetic hydroxyapatites incorporating small amounts of Si have shown improved biological performances in terms of enhanced bone apposition, bone in-growth and cell-mediated degradation. This paper reports a systematic investigation on Si-substituted hydroxyapatite (Si 1.40 wt%) nanopowders produced following two different conventional wet methodologies: (a) precipitation of Ca(NO 3 ) 2 .4H 2 O and (b) titration of Ca(OH) 2 . The influence of the synthesis process on composition, thermal behaviour and sinterability of the resulting nanopowders is studied. Samples were characterised by electron microscopy, induced coupled plasma atomic emission spectroscopy, thermal analysis, infrared spectroscopy, N 2 adsorption measurements, X-ray diffraction and dilatometry. Semicrystalline Si-substituted hydroxyapatite powders made up of needle-like nanoparticles were obtained, the specific surface area ranged between 84 and 110 m 2 /g. Pure and Si-substituted hydroxyapatite nanopowders derived from Ca(NO 3 ) 2 .4H 2 O decomposed around 1000 deg. C. Si-substituted hydroxyapatite nanopowders obtained from Ca(OH) 2 were thermally stable up to 1200 deg. C and showed a distinct decreased thermal stability with respect to the homologous pure sample. Si-substituted hydroxyapatites exhibited higher sintering temperature and increased total shrinkage with respect to pure powders. Nanostructured dense ceramics were obtained by sintering at 1100 deg. C Si-substituted hydroxyapatites derived from Ca(OH) 2

  5. Cation Substitution in Earth‐Abundant Kesterite Photovoltaic Materials

    Science.gov (United States)

    Li, Jianjun; Wang, Dongxiao; Li, Xiuling; Zeng, Yu

    2018-01-01

    Abstract As a promising candidate for low‐cost and environmentally friendly thin‐film photovoltaics, the emerging kesterite‐based Cu2ZnSn(S,Se)4 (CZTSSe) solar cells have experienced rapid advances over the past decade. However, the record efficiency of CZTSSe solar cells (12.6%) is still significantly lower than those of its predecessors Cu(In,Ga)Se2 (CIGS) and CdTe thin‐film solar cells. This record has remained for several years. The main obstacle for this stagnation is unanimously attributed to the large open‐circuit voltage (V OC) deficit. In addition to cation disordering and the associated band tailing, unpassivated interface defects and undesirable energy band alignment are two other culprits that account for the large V OC deficit in kesterite solar cells. To capture the great potential of kesterite solar cells as prospective earth‐abundant photovoltaic technology, current research focuses on cation substitution for CZTSSe‐based materials. The aim here is to examine recent efforts to overcome the V OC limit of kesterite solar cells by cation substitution and to further illuminate several emerging prospective strategies, including: i) suppressing the cation disordering by distant isoelectronic cation substitution, ii) optimizing the junction band alignment and constructing a graded bandgap in absorber, and iii) engineering the interface defects and enhancing the junction band bending. PMID:29721421

  6. Cation Substitution in Earth-Abundant Kesterite Photovoltaic Materials.

    Science.gov (United States)

    Li, Jianjun; Wang, Dongxiao; Li, Xiuling; Zeng, Yu; Zhang, Yi

    2018-04-01

    As a promising candidate for low-cost and environmentally friendly thin-film photovoltaics, the emerging kesterite-based Cu 2 ZnSn(S,Se) 4 (CZTSSe) solar cells have experienced rapid advances over the past decade. However, the record efficiency of CZTSSe solar cells (12.6%) is still significantly lower than those of its predecessors Cu(In,Ga)Se 2 (CIGS) and CdTe thin-film solar cells. This record has remained for several years. The main obstacle for this stagnation is unanimously attributed to the large open-circuit voltage ( V OC ) deficit. In addition to cation disordering and the associated band tailing, unpassivated interface defects and undesirable energy band alignment are two other culprits that account for the large V OC deficit in kesterite solar cells. To capture the great potential of kesterite solar cells as prospective earth-abundant photovoltaic technology, current research focuses on cation substitution for CZTSSe-based materials. The aim here is to examine recent efforts to overcome the V OC limit of kesterite solar cells by cation substitution and to further illuminate several emerging prospective strategies, including: i) suppressing the cation disordering by distant isoelectronic cation substitution, ii) optimizing the junction band alignment and constructing a graded bandgap in absorber, and iii) engineering the interface defects and enhancing the junction band bending.

  7. Effect of Gd{sup 3+} substitution on structural, magnetic, dielectric and optical properties of nanocrystalline CoFe{sub 2}O{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Joshi, Seema [Department of Physics and Materials Science and Engineering, Jaypee Institute of Information Technology, Noida 201307 (India); Kumar, Manoj, E-mail: mkumar.phy@gmail.com [Department of Physics and Materials Science and Engineering, Jaypee Institute of Information Technology, Noida 201307 (India); Chhoker, Sandeep [Department of Physics and Materials Science and Engineering, Jaypee Institute of Information Technology, Noida 201307 (India); Kumar, Arun; Singh, Mahavir [Department of Physics, Himachal Pradesh University, Shimla 5 (India)

    2017-03-15

    Nanoparticles of CoGd{sub x}Fe{sub 2−x}O{sub 4} with x=0.0, 0.03, 0.05, 0.07, 0.10 and 0.15 were synthesized by co-precipitation method. Gd{sup 3+} substitution effect on different properties of nanocrystalline CoFe{sub 2}O{sub 4} has been studied. X-ray diffraction and Raman spectroscopy confirmed the formation of single phase cubic mixed spinel structure. Cation distribution has been proposed from Rietveld refined data. Mössbauer spectra at room temperature showed two ferrimagnetic Zeeman sextets with one superparamagnetic doublet. Mössbauer parameters suggested that Gd{sup 3+} ions occupy the octahedral site in CoFe{sub 2}O{sub 4}. Room temperature magnetic measurements exhibited that the saturation magnetization decreased from 91 emu/gm to 54 emu/gm for x=0.0 to 0.15 samples. The coercivity decreased from 1120 Oe to 340 Oe for x=0.0 to 0.07 samples and increased from 400 Oe to 590 Oe for x=0.10 and 0.15 samples, respectively. Raman analysis showed that the degree of inversion with Gd{sup 3+} substitution supporting the variation of coercivity. Electron spin resonance spectra revealed the dominancy of superexchange interactions in these samples. Optical band gap measurement suggested that all samples are indirect band gap materials and band gap has been decreased with Gd{sup 3+} substitution. Both dielectric constant and dielectric loss is found to decrease because of the decrease in hopping rate with the Gd{sup 3+} substitution for Fe{sup 3+} at the octahedral sites. Low dielectric loss suggested the applicability of Gd{sup 3+} doped CoFe{sub 2}O{sub 4} nanoparticles for high frequency microwave device applications. - Highlights: • Gd{sup 3+} ions were successfully added in to the spinel lattice of CoFe{sub 2}O{sub 4}. • Magnetic hysteresis loss is influenced by Gd{sup 3+} doping. • All doped samples exhibit normal dielectric dispersion behaviour of spinel ferrites. • UV–vis diffuse spectroscopy concludes band gap is reduced by Gd{sup 3+} doping.

  8. The effect of simultaneous substitution on the electronic band structure and thermoelectric properties of Se-doped Co3SnInS2 with the Kagome lattice

    OpenAIRE

    Fujioka, Masaya; Shibuya, Taizo; Nakai, Junya; Yoshiyasu, Keigo; Sakai, Yuki; Takano, Yoshihiko; Kamihara, Yoichi; Matoba, Masanori

    2012-01-01

    The thermoelectric properties and electronic band structures for Se-doped Co3SnInS2 were examined. The parent compound of this material (Co3Sn2S2) has two kinds of Sn sites (Sn1 and Sn2 sites). The density functional theory (DFT) calculations show that the indium substitution at the Sn2 site induces a metallic band structure, on the other hand, a semiconducting band structure is obtained from substitution at the Sn1 site. However, according to the previous reports, since the indium atom prefe...

  9. Boomerang-type substitution reaction: reactivity of fullerene epoxides and a halofullerenol.

    Science.gov (United States)

    Jia, Zhenshan; Zhang, Xiang; Zhang, Gaihong; Huang, Shaohua; Fang, Hao; Hu, Xiangqing; Li, Yuliang; Gan, Liangbing; Zhang, Shiwei; Zhu, Daoben

    2007-02-05

    The C(s)-symmetric fullerene chlorohydrin C60(Cl)(OH)(OOtBu)4 reacts with 4-dimethylaminopyridine (DMAP) and 1,4-diazabicyclo[2.2.2]octane (DABCO) to yield two isomers with the formula C60(O)(OOtBu)4 in good yields. These isomers differ with respect to the location of the epoxy functionality. The one from DMAP is C(s) symmetric, whereas that from DABCO is C1 symmetric with the epoxy group on the central pentagon. Two different mechanisms are proposed to explain the chemoselectivity of these reactions. The reaction with DMAP involves single-electron transfer as the key step; DMAP acts as the electron donor. A combination of an oxygen-atom shift and S(N)2'' processes (boomerang substitution) are responsible for the formation of isomer with DACBO. Various related reactions support the proposed mechanisms. The structures of new fullerene derivatives were determined by spectroscopy, single-crystal X-ray analysis, and chemical correlation experiments.

  10. Kinetics on the reaction of substituted quinolines and p-substituted benzoylchlorides under various pressures

    International Nuclear Information System (INIS)

    Kim, Young Cheul; Lim, Jong Wan; Choi, Sung Yong; Kim, Se Kyong

    1999-01-01

    The reaction rates of substituted quinolines(6-CH 3 C 9 H 7 N, C 9 H 7 N) with p-substituted benzoylchlorides(p-CH 3 , p-H, p-NO 2 ) have been measured by conductometry in acetonitrile, and the rate constants are determined at various temperatures (10,15, 20, 25 .deg. C) and pressures(1, 200, 500, 1000bar). From the values of rate constants, the activation parameters(Ea, ΔV ≠ , ΔS ≠ , and ΔG ≠ ) and the pressure dependence of Hammett ρ values were determined. The rate constants increase as a function of temperatures and pressures, and are further increase by introduction the electron donor substituents in nucleophile(p-CH 3 ) or electron acceptor(p-NO 2 ) substituents in substrate. The activation volume, and the activation entropy are all negative. Hammett ρ values are also negative for nucleophile (ρ X ) and positive for the substrate (ρ Y ) over the pressure range studied. The results of kinetic studies for pressure and substituent show that these reactions proceed in typical S N 2 reaction mechanism and 'associative S N 2' in which bond formation favored with increasing pressures

  11. Kinetic study of the substitution of [Tc(tu)6]3+ by polyaminocarboxylic acids

    International Nuclear Information System (INIS)

    Torres, J.; Gonalez, R.; Kremer, C.; Kremer, E.; Leon, A.

    1997-01-01

    Substitution route has been traditionally proposed for the synthesis of new Tc complexes. In particular, Tc(III) coordination compounds can be successfully prepared by substitution on [Tc(tu) 6 ] 3+ (tu = thiourea). In this substitution reaction, TcO 2 is a side product that should be minimized. The success of these synthetic procedures is based on controlling the reaction conditions in order that pure substitution could be faster enough compared to decomposition. In this work, the substitution of [Tc(tu) 6 ] 3+ by polycarboxylic acids (ethylenediaminetetraacetate (edta), diethylenetriaminepentaacetate (dtpa), N-tris(2-amino-ethyl)amin N', N', N '' , N '' , N ''' , N ''' -hexaacetate (ttaha) and 3-bromo-2,4,6-trimethylacetanilideiminodiacetate (mebrofenin)) is kinetically studied in order to obtain the best conditions for preparing Tc(III) complexes. As a general conclusion, substitution constants are strongly dependent on the pH. k obs values fall in the range 0.1-13 x 10 -2 M -1 s -1 , depending on the pH value and the temperature. No strong differences are found with different incoming ligands. For the four ligands (L), a straight line is obtained when plotting log k obs /([L m- ]) vs. pH. This is consistent with a rate constant k obs = {k 0 + Σk n [H + ] n /K n }[L m- ], where n represents the charge of the incoming ligand and m is the maximum value of n. (orig.)

  12. Spinel FeCo2S4 nanoflower arrays grown on Ni foam as novel binder-free electrodes for long-cycle-life supercapacitors

    Science.gov (United States)

    Deng, Cuifen; Yang, Lishan; Yang, Chunming; Shen, Ping; Zhao, Liping; Wang, Zhiyu; Wang, Chunhui; Li, Junhua; Qian, Dong

    2018-01-01

    Spinel FeCo2S4 nanoflower arrays grown on Ni foam (FeCo2S4@Ni) have been successfully fabricated via a facile hydrothermal sulfurization of the corresponding FeCo2O4 precursor. The results of X-ray diffraction and X-ray photoelectron spectroscopy characterizations affirm that partial Co2+/Co3+ ions in Co3S4 have been substituted by Fe2+/Fe3+ ions to form FeCo2S4. The obtained FeCo2S4@Ni exhibits an ultrahigh specific capacitance (1644.07 mF cm-2 at 50 mA cm-2) and a supreme cycling stability (∼100% after 10,000 cycles at 50 mA cm-2) as binder-free electrodes for supercapacitors. The cycling stability of the fabricated product is the highest among the documented ternary metallic sulfides so far. The excellent supercapacitive performance of FeCo2S4@Ni emanates from the unique architectures of Fe2Co2S4 nanoflower arrays constituted by ultrathin nanoflakes, three-dimensional porous and conductive Ni foam, and solid skeleton of Ni foam for robust connections to the Fe2Co2S4.

  13. Synthesis and Application of Acid Dyes Based on 3-(4-Aminophenyl-5-benzylidene-2-substituted phenyl-3, 5-dihydroimidazol-4-one

    Directory of Open Access Journals (Sweden)

    Devang N. Wadia

    2008-01-01

    Full Text Available A series of eight novel heterocyclic based monoazo acid dyes were synthesized using various substituted imidazol-4-one as diazo component and coupled with various amino-napthol sulphonic acids. The resultant dyes were characterized using standard spectroscopic methods and then dyeing performance on wool fabric was assessed. Final results concluded that exhaustion (%E of the dyes on wool fibers increased with decreasing pH of application and that fixation (%F of the dyes on wool fibers increased with increasing pH of application and the highest total fixation efficiency was achieved at pH 5. Wash and light fastness properties of prepared dyes showed encouraging results.

  14. Magnetic, hyperthermic and structural properties of zn substituted CaFe2O4 powders

    Science.gov (United States)

    Kheradmand, Abbas; Vahidi, Omid; Masoudpanah, S. M.

    2018-03-01

    In the present study, we have synthesized single phase Ca1 - x Zn x Fe2O4 powders by hydrothermal method. The cation distribution between the tetrahedral and octahedral sites in the spinel structure and the magnetic properties as a function of the zinc substitution have been investigated by X-ray diffraction (XRD), infrared spectroscopy and vibrating sample magnetometer methods. The obtained XRD pattern indicated that the synthesized particles had single phase cubic spinel structure with no impurity. The magnetic measurements showed that the saturation magnetization increased from 83 to 98 emu/g with the addition of zinc due to the decrease of inversity. The particle size observed by electron microscopy decreased from 1.38 to 0.97 µm with the increase of zinc addition. The Ca0.7Zn0.3Fe2O4 powders exhibited appropriate heating capability for hyperthermia applications with the maximum AC heating temperature of 20 °C and specific loss power of 9.29 W/g.

  15. Cation Radical Accelerated Nucleophilic Aromatic Substitution via Organic Photoredox Catalysis.

    Science.gov (United States)

    Tay, Nicholas E S; Nicewicz, David A

    2017-11-15

    Nucleophilic aromatic substitution (S N Ar) is a direct method for arene functionalization; however, it can be hampered by low reactivity of arene substrates and their availability. Herein we describe a cation radical-accelerated nucleophilic aromatic substitution using methoxy- and benzyloxy-groups as nucleofuges. In particular, lignin-derived aromatics containing guaiacol and veratrole motifs were competent substrates for functionalization. We also demonstrate an example of site-selective substitutive oxygenation with trifluoroethanol to afford the desired trifluoromethylaryl ether.

  16. First principles prediction of the magnetic properties of Fe-X6 (X = S, C, N, O, F) doped monolayer MoS2

    KAUST Repository

    Feng, Nan; Mi, Wenbo; Cheng, Yingchun; Guo, Zaibing; Schwingenschlö gl, Udo; Bai, Haili

    2014-01-01

    Using first-principles calculations, we have investigated the electronic structure and magnetic properties of Fe-X 6 clusters (X = S, C, N, O, and F) incorporated in 4 4 monolayer MoS 2, where a Mo atom is substituted by Fe and its nearest S atoms are substituted by C, N, O, and F. Single Fe and Fe-F 6 substituions make the system display half-metallic properties, Fe-C 6 and Fe-N 6 substitutions lead to a spin gapless semiconducting behavior, and Fe-O 6 doped monolayer MoS 2 is semiconducting. Magnetic moments of 1.93, 1.45, 3.18, 2.08, and 2.21...? B are obtained for X = S, C, N, O, and F, respectively. The different electronic and magnetic characters originate from hybridization between the X and Fe/Mo atoms. Our results suggest that cluster doping can be an efficient strategy for exploring two-dimensional diluted magnetic semiconductors.

  17. First principles prediction of the magnetic properties of Fe-X6 (X = S, C, N, O, F) doped monolayer MoS2

    KAUST Repository

    Feng, Nan

    2014-02-05

    Using first-principles calculations, we have investigated the electronic structure and magnetic properties of Fe-X 6 clusters (X = S, C, N, O, and F) incorporated in 4 4 monolayer MoS 2, where a Mo atom is substituted by Fe and its nearest S atoms are substituted by C, N, O, and F. Single Fe and Fe-F 6 substituions make the system display half-metallic properties, Fe-C 6 and Fe-N 6 substitutions lead to a spin gapless semiconducting behavior, and Fe-O 6 doped monolayer MoS 2 is semiconducting. Magnetic moments of 1.93, 1.45, 3.18, 2.08, and 2.21...? B are obtained for X = S, C, N, O, and F, respectively. The different electronic and magnetic characters originate from hybridization between the X and Fe/Mo atoms. Our results suggest that cluster doping can be an efficient strategy for exploring two-dimensional diluted magnetic semiconductors.

  18. Multigram Synthesis of a Chiral Substituted Indoline Via Copper-Catalyzed Alkene Aminooxygenation.

    Science.gov (United States)

    Sequeira, Fatima C; Bovino, Michael T; Chipre, Anthony J; Chemler, Sherry R

    2012-05-01

    (S)-5-Fluoro-2-(2,2,6,6-tetramethylpiperidin-1-yloxymethyl)-1-tosylindoline, a 2-methyleneoxy-substituted chiral indoline, was synthesized on multigram scale using an efficient copper-catalyzed enantioselective intramolecular alkene aminooxygenation. The synthesis is accomplished in four steps and the indoline is obtained in 89% ee (>98% after one recrystallization). Other highlights include efficient gram-scale synthesis of the (4R,5S)-di-Ph-box ligand and efficient separation of a monoallylaniline from its bis(allyl)aniline by-product by distillation under reduced pressure.

  19. The effect of simultaneous substitution on the electronic band structure and thermoelectric properties of Se-doped Co3SnInS2 with the Kagome lattice

    Science.gov (United States)

    Fujioka, Masaya; Shibuya, Taizo; Nakai, Junya; Yoshiyasu, Keigo; Sakai, Yuki; Takano, Yoshihiko; Kamihara, Yoichi; Matoba, Masanori

    2014-12-01

    The thermoelectric properties and electronic band structures for Se-doped Co3SnInS2 were examined. The parent compound of this material (Co3Sn2S2) has two kinds of Sn sites (Sn1 and Sn2 sites). The density functional theory (DFT) calculations show that the indium substitution at the Sn2 site induces a metallic band structure, on the other hand, a semiconducting band structure is obtained from substitution at the Sn1 site. However, according to the previous reports, since the indium atom prefers to replace the tin atom at the Sn1 site rather than the Sn2 site, the resistivity of Co3SnInS2 shows semiconducting-like behavior. In this study we have demonstrated that metallic behavior and a decrease in resistivity for Se-doped Co3SnInS2 occurs without suppression of the Seebeck coefficient. From the DFT calculations, when the selenium content is above 0.5, the total crystallographic energy shows that a higher indium occupancy at Sn2 site is more stable. Therefore, it is suggested that the selenium doping suppress the site preference for indium substitution. This is one of the possible explanations for the metallic conductivity observed in Se-doped Co3SnInS2

  20. Virtual substitution scan via single-step free energy perturbation.

    Science.gov (United States)

    Chiang, Ying-Chih; Wang, Yi

    2016-02-05

    With the rapid expansion of our computing power, molecular dynamics (MD) simulations ranging from hundreds of nanoseconds to microseconds or even milliseconds have become increasingly common. The majority of these long trajectories are obtained from plain (vanilla) MD simulations, where no enhanced sampling or free energy calculation method is employed. To promote the 'recycling' of these trajectories, we developed the Virtual Substitution Scan (VSS) toolkit as a plugin of the open-source visualization and analysis software VMD. Based on the single-step free energy perturbation (sFEP) method, VSS enables the user to post-process a vanilla MD trajectory for a fast free energy scan of substituting aryl hydrogens by small functional groups. Dihedrals of the functional groups are sampled explicitly in VSS, which improves the performance of the calculation and is found particularly important for certain groups. As a proof-of-concept demonstration, we employ VSS to compute the solvation free energy change upon substituting the hydrogen of a benzene molecule by 12 small functional groups frequently considered in lead optimization. Additionally, VSS is used to compute the relative binding free energy of four selected ligands of the T4 lysozyme. Overall, the computational cost of VSS is only a fraction of the corresponding multi-step FEP (mFEP) calculation, while its results agree reasonably well with those of mFEP, indicating that VSS offers a promising tool for rapid free energy scan of small functional group substitutions. This article is protected by copyright. All rights reserved. © 2016 Wiley Periodicals, Inc.

  1. Synthesis, antitumor and antimicrobial activity of novel 1-substituted phenyl-3-[3-alkylamino(methyl)-2-thioxo-1,3,4-oxadiazole-5-yl] beta-carboline derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Savariz, Franciele C.; Formagio, Anelise S. N.; Barbosa, Valeria A.; Sarragiotto, Maria Helena [Universidade Estadual de Maringa (UEM), PR (Brazil). Dept. de Quimica; Foglio, Mary Ann; Carvalho, Joao E. de; Duarte, Marta C.T. [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Centro Pluridisciplinar de Pesquisas Quimicas, Biologicas e Agricolas; Dias Filho, Benedito P. [Universidade Estadual de Maringa (UEM), PR (Brazil). Dept. de Analises Clinicas

    2010-07-01

    With the purpose of activity enhancement of 1-substituted phenyl-3-(2-thioxo-1,3,4-oxadiazole-5-yl) beta-carbolines 1a-c, reported as potential antitumor agents in our previous study, herein we report the synthesis and antitumor activity evaluation of several novel Mannich bases 2-7(a-c), by the introduction of different alkylamino(methyl) groups in the 1,3,4-oxadiazole unity of 1a-c. The antimicrobial activities of 1a-c and of 2-7(a-c) were also evaluated. Additionally, an in silico study of the ADME properties of novel synthesized beta-carboline derivatives 2-7(a-c) was performed by evaluation of their Lipinski's parameters and topological polar surface area (TPSA) and percentage of absorption (% ABS) data. (author)

  2. Palaeointensity Results from 1951 and 1995 Lava Flows, Fogo, Cape Verde: A Comparison between Thellier and LTD-DHT Shaw Methods

    Science.gov (United States)

    Brown, M. C.; Cropsey, J.; Bowles, J. A.; Feinberg, J. M.

    2009-12-01

    As part of an ongoing effort to link the success rate of palaeointensity experiments to specific rock magnetic properties, we present new palaeointensity results from basaltic lavas erupted in 1951 and 1995 on the island of Fogo, Cape Verde. Both Thellier and LTD-DHT Shaw palaeointensity experiments were used to estimate the historical field strength. The intensity of the field during these eruptions is constrained by data from the Mbour geomagnetic observatory (Senegal) and IGRF10. In 1951, the magnetic field intensity at Fogo was approximately 33.8 µT during the eruption of three distinct surface flows, covering approximately 14 km2. The field intensity was approximately 32.5 µT during a 1995 eruption of one large flow that extends 4 km2 across the caldera floor. Different volcanic textures were sampled from multiple sites within both the 1951 and 1995 lava flows, including glass-rich pahoehoe and aa flows, highly vesicular flows, and massive non-vesicular lava. Detailed rock magnetic measurements demonstrate that each site and texture displays distinctively different rock magnetic properties. We assess possible links between the outcome of the Thellier and LTD-DHT palaeointensity experiments and the distribution of magnetic domain states, average oxidation state, and laboratory induced alteration.

  3. Substitutional Doping for Aluminosilicate Mineral and Superior Water Splitting Performance

    Science.gov (United States)

    Zhang, Yi; Fu, Liangjie; Shu, Zhan; Yang, Huaming; Tang, Aidong; Jiang, Tao

    2017-07-01

    Substitutional doping is a strategy in which atomic impurities are optionally added to a host material to promote its properties, while the geometric and electronic structure evolution of natural nanoclay mineral upon substitutional metal doping is still ambiguous. This paper first designed an efficient lanthanum (La) doping strategy for nanotubular clay (halloysite nanotube, HNT) through the dynamic equilibrium of a substitutional atom in the presence of saturated AlCl3 solution, and systematic characterization of the samples was performed. Further density functional theory (DFT) calculations were carried out to reveal the geometric and electronic structure evolution upon metal doping, as well as to verify the atom-level effect of the La doping. The CdS loading and its corresponding water splitting performance could demonstrate the effect of La doping. CdS nanoparticles (11 wt.%) were uniformly deposited on the surface of La-doped halloysite nanotube (La-HNT) with the average size of 5 nm, and the notable photocatalytic hydrogen evolution rate of CdS/La-HNT reached up to 47.5 μmol/h. The results could provide a new strategy for metal ion doping and constructive insight into the substitutional doping mechanism.

  4. Substitution of 125-I-T3, 125-I-T4 and 125-I-TSH produced in the ININ, in commercial boxes for radioimmunoessay

    International Nuclear Information System (INIS)

    Delgado S, B.; Zambrano A, F.; Lavalley E, C.; Ferro F, G.; Lezama C, J.

    1991-03-01

    Due to the half, relatively short life, of the I-125 used in the radioinmunoanalisis (he/she LAUGHS) of hormones realcionadas with the thyroid, frequently it is observed that they are the other reagents of commercial cases without using, reason for the one which you piede the possibility to use in their entirety statements kits for the CREEK, what causes lost economic and another type of deficiencies. Presently work the results are presented obtained on the characteristics of quality of commercial stuches for the CREEK of hormones of the thyroid profile (T3, T4 and TSH), after substituting to the different radiotrazadores in this cases. The marcaje of the hormones with I-125 was made by means of the method of the cloramina T with 25 seconds of reaction for each hormone, purifying the T3 and the T4 for cromatografia liquidates of high efficiency and to the TSH for cromatografia of likeness in a column of cellulose microcristalina of 6 x 0.8 cm. the substitution of the radiotrazador is made in the commercial cases and the protocol was continued proposed by the makers, giving a coefficient of correlation of -0-997, as a result after the comparison of the straight line among the cases without and with substitution of the radiotrazador; besides certain parameters of quality of the such rehearsals as: the maximum unions (50%+-5) and inespecifica (<5%), slope of the straight line (-2.1 + - 0.2), and other coming from the use of samples of control of quality. We can conclude that at the moment we have in the ININ radiotrazadores of T3, T4 and TSH of good quality, like to be substituted in commercial cases and to use this way to the maximum these games of reagents that are so expensive. (Author)

  5. The inhibition of LPS-induced splenocyte proliferation by ortho-substituted and microbially dechlorinated polychlorinated biphenyls is associated with a decreased expression of cyclin D2

    International Nuclear Information System (INIS)

    Smithwick, L. Ashley; Quensen, John F.; Smith, Andrew; Kurtz, David T.; London, Lucille; Morris, Pamela J.

    2004-01-01

    Immunological effects of polychlorinated biphenyls (PCBs) have been demonstrated in our laboratories with the preferential inhibition of lipopolysaccharide (LPS)-induced splenocyte proliferation by ortho-substituted PCB congeners. An investigation of the mechanism behind this immunotoxicity revealed an interruption in the progression of murine lymphocytes from G 0 /G 1 into S phase by Aroclor 1242 and the di-ortho-substituted congener, 2,2'-chlorobiphenyl (CB), whereas, a non-ortho-substituted congener, 4,4'-CB, did not affect cell cycle progression. This interruption of cell cycle progression by 2,2'-CB and Aroclor 1242 was associated with a decreased expression of the cell cycle regulatory protein, cyclin D2, while expression was not affected by exposure to the non-ortho-substituted 4,4'-CB. These results suggest the preferential inhibition of LPS-induced splenocyte proliferation by ortho-substituted congeners is a result of a decreased expression of cyclin D2, which leads to an interruption in cell cycle progression. In addition, PCB mixtures with an increased percentage of chlorines in the ortho position following an environmentally occurring degradation process inhibited LPS-induced proliferation, interrupted cell cycle progression, and decreased cyclin D2 expression. This study provides evidence for a mechanism of action of the immunological effects of ortho-substituted individual congeners as well as environmentally relevant mixtures enriched in congeners with this substitution pattern

  6. Synthesis of Novel 2-(Substituted aminoalkylthiopyrimidin-4(3H-ones as Potential Antimicrobial Agents

    Directory of Open Access Journals (Sweden)

    Mohamed I. Attia

    2013-12-01

    Full Text Available 5-Alkyl-6-(substituted benzyl-2-thiouracils 3a,c were reacted with (2-chloroethyl diethylamine hydrochloride to afford the corresponding 2-(2-diethylaminoethylthiopyrimidin- 4(3H-ones 4a,b. Reaction of 3a–c with N-(2-chloroethylpyrrolidine hydrochloride and/or N-(2-chloroethylpiperidine hydrochloride gave the corresponding 2-[2-(pyrrolidin-1-ylethyl]-thiopyrimidin-4(3H-ones 5a–c and 2-[2-(piperidin-1-ylethyl]thiopyrimidin-4(3H-ones 6a,b, respectively. Treatment of 3a–d with N-(2-chloroethylmorpholine hydrochloride under the same reaction conditions formed the corresponding 2-[2-(morpholin-4-ylethyl]thiopyrimidines 6c–f. On the other hand, 3a,b were reacted with N-(2-bromoethylphthalimide and/or N-(3-bromopropylphthalimide to furnish the corresponding 2-[2-(N-phthalimidoethyl]-pyrimidines 7a,b and 2-[3-(N-phthalimido-propyl]pyrimidines 7c,d, respectively. Compounds 3a–d, 4a,b, 5a–c, 6a–f and 7a–d were screened against Gram-positive bacteria (Staphylococcus aureus ATCC 29213, Bacillus subtilis NRRL 4219 and Bacillus cereus, yeast-like pathogenic fungus (Candida albicans ATCC 10231 and a fungus (Aspergillusniger NRRL 599. The best antibacterial activity was displayed by compounds 3a, 3b, 4a, 5a, 5b, 6d, 6f, 7b and 7d, whereas compounds 4b, 5b, 5c, 6a, 6b and 6f exhibited the best antifungal activity.

  7. Synthesis of 2-[4-(10H-Substituted Phenothiazine-3-yl-6-Pyrimidin-2-Phenylthiol/ol/amine/thiol] Pyrroles

    Directory of Open Access Journals (Sweden)

    Meghasham Narule

    2007-01-01

    Full Text Available 2-[4-Hydroxy benz-1(propene-1-one]Pyrrole II on treatment with phenyl thiourea, guanidine carbonate, urea and thiourea in alcoholic KOH yielded compounds III, IV, V, VI which on treatment with different aryl anilines gave compounds VII, VIII, IX, X which under goes cyclisation with sulphur and iodine to give 2-[4-(10H-substituted phenothiazine-3-yl-6-pyrimidin-2-phenylthiol/-ol/-amine/-thiol] pyrrole XI(a-j, XII(a-j, XIII(a-j and XIV(a-j respectively. The structural products were characterized by elemental analysis and spectral data.

  8. Synthesis and X-ray Structural Studies of a Substituted 2,3,4,5-Tetrahydro-1H-3-benzazonine and a 1,2,3,5-Tetrahydro-4,3-benzoxazonine

    Directory of Open Access Journals (Sweden)

    Timothy S. Bailey

    2014-12-01

    Full Text Available Using a common 1-(1-phenylethenyl-1,2,3,4-tetrahydroisoquinoline precursor to the required ylide or N-oxide intermediate, the Stevens [2,3] and analogous Meisenheimer [2,3] sigmatropic rearrangements have been applied to afford concise syntheses of phenyl -substituted representatives of each of the reduced 1H-3-benzazonine and 4,3-benzoxazonine systems, respectively. Single crystal X-ray structure determinations were employed to define the conformational characteristics for each ring type.

  9. The effect of substitutional elements (Al, Co) in LaNi4.5M0.5 on the lattice defect formation in the initial hydrogenation and dehydrogenation

    International Nuclear Information System (INIS)

    Sakaki, Kouji; Akiba, Etsuo; Mizuno, Masataka; Araki, Hideki; Shirai, Yasuharu

    2009-01-01

    The formation of the vacancy and dislocation by the initial hydrogenation and dehydrogenation in LaNi 4.5 M 0.5 (M = Al, Co, and Ni) was observed by means of the positron lifetime technique. The concentrations of vacancy introduced by these processes were 0.25, 0.13 and 0.01 at.% for LaNi 5 , LaNi 4.5 Co 0.5 and LaNi 4.5 Al 0.5 , respectively. Al substitution into LaNi 5 significantly prevented from vacancy formation, compared with LaNi 5 and LaNi 4.5 Co 0.5 . In LaNi 4.5 Al 0.5 , the increase of the hardness and the enhancement of the pulverization, i.e. enhancement of the formation of micro cracks compared with LaNi 5 were observed while the Co substitution had little effect on pulverization and hardness as well as vacancy formation. These results show that the formation of micro cracks became more active process by Al substitution than the formation of the lattice defects to release the strain energy generated by the hydride formation because of the higher formation energy of the lattice defects in LaNi 4.5 Al 0.5 , although both the formation of micro cracks and lattice defects were still observed in all alloys we studied

  10. Synthesis of visible light active Gd3+-substituted ZnFe2O4 nanoparticles for photocatalytic and antibacterial activities

    Science.gov (United States)

    Patil, S. B.; Bhojya Naik, H. S.; Nagaraju, G.; Viswanath, R.; Rashmi, S. K.

    2017-08-01

    In the present analysis, we study the assembly of a low-cost and visible light active ZnFe2-xGdxO4 ( x = 0 , 0.3, 0.5 and 0.7) nanoparticles (NPs) photocatalyst. The synthesized samples were characterized by several physicochemical techniques, such as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), UV-Visible absorption spectroscopy (UV-Vis), scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM). The phase transition from cubic to orthorhombic was confirmed by XRD patterns. The increase in the concentration of Gd3+ substitution in ZnFe2O4 NPs enhances the redshift of absorption in the visible region of UV-Vis absorption spectra and reduces the band gap. In the photo-Fenton-type reaction, the gadolinium-substituted zinc ferrite (ZGF) NPs exhibit a significant catalytic activity for the degradation of methylene blue (99% in 90 minutes) under visible light (500W xenon lamp) with respect to bare samples (95% in 240 minutes) and they also show an excellent reusability nature. These materials were also screened for antibacterial activity against Gram-negative bacteria strains ( Pseudomonas aeruginosa and Escherichia coli).

  11. The influence of generic substitution on the content of patient-pharmacist communication in Swedish community pharmacies

    DEFF Research Database (Denmark)

    Olsson, Erika; Wallach-Kildemoes, Helle; Ahmed, Ban

    2017-01-01

    OBJECTIVES: The objective was to study the relationship between the length and content of patient-pharmacist communication in community pharmacies, and generic substitution. METHODS: The study was conducted in six community pharmacies in Sweden. Non-participant observations with audio recordings...... for differences in time spent on different categories. KEY FINDINGS: In encounters where generic substitution occurred more time (19.2 s) was spent on non-medical (for instance administrative or economical) issues (P = 0.01, 95% confidence interval 4.8-33.6). However, the total time of the encounter...... to those with only elementary school education. CONCLUSIONS: Occurrence of generic substitution was correlated with more time spent on communicating on non-medical, but not on medical, issues. No extra time was spent on medical information for the groups normally overrepresented among those with low health...

  12. Beyond Simulation As Substitution: From Mixed Reality To Ego-Shots

    OpenAIRE

    Alberich Pascual, Jordi; San Cornelio Esquerdo, Gemma

    2012-01-01

    The dominant formulation of simulation theories in the 1980s and 1990s (Baudrillard, Lévy et al.) suggested a theoretical and technological paradigm based on the impersonation (when not substitution) of the real by the virtual. The present article explores the recent emergence of an integrated, mixed or altered conception of virtualisation in regards to the real, but no longer a substitutive one: a conception that is related to a significant set of digital technologies and current audiovisual...

  13. 40 CFR 721.2577 - Copper complex of (substituted sulfonaphthyl azo substituted phenyl) disulfonaphthyl azo, amine...

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Copper complex of (substituted... Copper complex of (substituted sulfonaphthyl azo substituted phenyl) disulfonaphthyl azo, amine salt... substances identified generically as copper complex of (substituted sulfonaphthyl azo substituted phenyl...

  14. Composites organiques-inorganiques pour la substitution et la réparation osseuse : concepts, premiers résultats et potentialités Organic-inorganic composites for bone substitute and bone repair applications: concepts, first results and potentialities

    Directory of Open Access Journals (Sweden)

    Peroglio Marianna

    2013-11-01

    Full Text Available Ce document présente un très bref aperçu de l'intérêt des matériaux composites organique – inorganique pour la substitution et la réparation osseuse. Deux types de composites sont présentés. Dans une première partie, des matériaux poreux en céramique ou bio-verre élaborés par la technologie des poudres sont imprégnés par un polymère. Cette imprégnation se traduit par une forte augmentation de l'énergie à la rupture du squelette céramique, permettant de limiter le risque de rupture fragile. L'augmentation des propriétés mécaniques des substituts osseux céramiques par une phase polymère peut être mise en regard des mécanismes de renforcement présents dans l'os et du rôle du collagène sur la ténacité de celui-ci. Dans une deuxième partie, des composites denses sont élaborés par des technologies de plasturgie, qui permettent de réaliser des produits de formes complexes. Les phases polymères et céramiques sont ici choisies pour leurs caractères respectifs résorbable et ostéo-inducteur. Ces composites permettent la création rapide d'hydroxyapatite à leur surface et accélèrent la guérison osseuse. A terme, ils sont résorbés. Ces deux exemples démontrent les potentialités de tels multi-matériaux architecturés pour la réalisation de substituts osseux plus résistants mécaniquement et apportant de nouvelles fonctionnalités, ainsi que pour la production de produits d'ostéosynthèse favorisant les processus de guérison osseuse. Here we show a brief outline of organic-inorganic composites for bone substitute and bone repair applications. Two types of composites are presented. In a first strategy, porous ceramics and bioactive glasses processed by sintering methods are impregnated by a polymer. The strong improvement of the mechanical properties of the ceramic scaffolds by a polymer phase can be linked to the one present in bone with the role of collagen on bone toughness. In a second strategy, a

  15. The influence of generic substitution on the content of patient-pharmacist communication in Swedish community pharmacies.

    Science.gov (United States)

    Olsson, Erika; Wallach-Kildemoes, Helle; Ahmed, Ban; Ingman, Pontus; Kaae, Susanne; Kälvemark Sporrong, Sofia

    2017-08-01

    The objective was to study the relationship between the length and content of patient-pharmacist communication in community pharmacies, and generic substitution. The study was conducted in six community pharmacies in Sweden. Non-participant observations with audio recordings and short structured interviews were conducted. Out of 32 pharmacists 29 agreed to participate (90.6%), as did 282 out of 407 patients (69.3%). Logistic regression analysis was applied to calculate odds ratio for occurrence of generic substitution. Linear regression (β-coefficients) was applied to test for differences in time spent on different categories. In encounters where generic substitution occurred more time (19.2 s) was spent on non-medical (for instance administrative or economical) issues (P = 0.01, 95% confidence interval 4.8-33.6). However, the total time of the encounter was not significantly longer. The amount of time spent on non-medical issues increased with age of patient (age 60+: β, 33 s, P communicating on non-medical, but not on medical, issues. No extra time was spent on medical information for the groups normally overrepresented among those with low health literacy. This study suggests that pharmacists need to further embrace their role in promoting rational use of medicines, not least when generic substitution occurs. © 2016 Royal Pharmaceutical Society.

  16. Recommendations for Adopting the International Code of Marketing of Breast-milk Substitutes Into U.S. Policy.

    Science.gov (United States)

    Soldavini, Jessica; Taillie, Lindsey Smith

    2017-08-01

    In 1981, the World Health Organization adopted the International Code of Marketing of Breast-milk Substitutes ( International Code), with subsequent resolutions adopted since then. The International Code contributes to the safe and adequate provision of nutrition for infants by protecting and promoting breastfeeding and ensuring that human milk substitutes, when necessary, are used properly through adequate information and appropriate marketing and distribution. Despite the World Health Organization recommendations for all member nations to implement the International Code in its entirety, the United States has yet to take action to translate it into any national measures. In 2012, only 22.3% of infants in the United States met the American Academy of Pediatrics recommendation of at least 6 months of exclusive breastfeeding. Countries adopting legislation reflecting the provisions of the International Code have seen increases in breastfeeding rates. This article discusses recommendations for translating the International Code into U.S. policy. Adopting legislation that implements, monitors, and enforces the International Code in its entirety has the potential to contribute to increased rates of breastfeeding in the United States, which can lead to improved health outcomes in both infants and breastfeeding mothers.

  17. Influence of Alkali Metal Substitution on the Phase Transition Behavior of CsGaQ2 (Q = S, Se

    Directory of Open Access Journals (Sweden)

    Daniel Friedrich

    2017-12-01

    Full Text Available The formation of solid solution series Cs1−xMxGaQ2-mC64 (M = K, Rb; Q = S, Se; x = 0–1 was studied by X-ray diffraction and spectroscopic methods, revealing a complete miscibility of CsGaQ2-mC64 with RbGaQ2 and KGaSe2, and a large miscibility gap with KGaS2. All solid solution members exhibit similar Raman spectra, indicating the covalent Ga-Q bonding character. The similar optical band gaps likewise further contribute to this conclusion. Up to a certain degree of substitution, these solid solutions undergo a phase transition similar to CsGaQ2-mC64. The influence of the substitution parameter x on phase transition process was investigated in situ using high-temperature X-ray powder diffraction experiments. Phase-pure solid solutions of the high-temperature polymorphs Cs1−xMxGaQ2-mC16 were obtained up to xmax(K = 0.1 and xmax(Rb = 0.3. The crystal structures of these new CsGaQ2-mC16 analogous high-temperature phases were refined from synchrotron diffraction data by Rietveld-refinement.

  18. Industrialization in Sub-Saharan Africa and import substitution policy

    Directory of Open Access Journals (Sweden)

    Ana Paula F. Mendes

    2014-03-01

    Full Text Available This article aims to contribute to the understanding of the process of import substitution in Sub-Saharan Africa. The process of industrialization in Sub-Saharan Africa occurred in two phases: a first step, even very early during the colonial regime began around the 1920s and ended in the late forties; a second phase of industrialization began in the late fifties and gained momentum in the sixties, when import substitution was implemented more widely. Although these countries were the last to embark on the strategy of import substitution, they followed the same steps of Latin American countries, and as the structural domestic and external constraints were too strong, the failure of the policy of import substitution arrived early and the negative impact on these economies had a greater magnitude.

  19. One-pot tandem Ugi-4CR/S(N)Ar approach to highly functionalized quino[2,3-b][1,5]benzoxazepines.

    Science.gov (United States)

    Ghandi, Mehdi; Zarezadeh, Nahid; Abbasi, Alireza

    2016-05-01

    We have developed a convenient and facile method for the synthesis of functionalized diverse quino[2,3-b][1,5]benzoxazepines. These new compounds were synthesized through a one-pot sequential Ugi-4CR/base-free intramolecular aromatic nucleophilic substitution (S(N)Ar) reaction in moderate to good yields from readily available starting materials. Structural confirmation of the products is confirmed by analytical data and X-ray crystallography.

  20. Ultrasound-Promoted Greener Synthesis of Novel Trifurcate 3-Substituted-chroman-2,4-dione Derivatives and Their Drug-Likeness Evaluation

    Directory of Open Access Journals (Sweden)

    Yu Xue

    2012-11-01

    Full Text Available An efficient and convenient approach for one-pot synthesis of 3-substituted chroman-2,4-diones via a three-component reaction of aromatic aldehydes, 4-hydroxy- coumarins and diverse pyrazolone derivatives was described. The combinatorial synthesis for this methodology was achieved by applying ultrasound irradiation in the absence of activator while making use of water as green solvent. Additionally, novel chroman-2,4-dione derivatives attached to an edaravone moiety represent an exploitable source of brand new anticancer agents. In comparison with conventional methods, experimental simplicity, good functional group tolerance, excellent yields, short routine, and atom efficiency are prominent features of this sonocatalyzed procedure.

  1. Spectrum designation and effect of Al substitution on the luminescence of Cr3+ doped ZnGa2O4 nano-sized phosphors

    International Nuclear Information System (INIS)

    Zhang Weiwei; Zhang Junying; Chen Ziyu; Wang Tianmin; Zheng Shukai

    2010-01-01

    Low-temperature photoluminescent spectra of ZnGa 2 O 4 :Cr 3+ nano-sized phosphors calcined at different temperatures were reported. The fine structure of the emission spectra has been designated to Cr 3+ ions in different sites including ideal octahedral, Zn-interstitial, Ga ZN 4 -Zn Ga 6 sites and Ga 2 O 3 impurity. The vibronic sidebands for both Stokes' and anti-Stokes' sides are related to the host lattice vibrations, which were confirmed by IR and Raman spectra. Al 3+ is substituted in Ga 3+ sites to form Zn(Ga 1-y Al y ) 2 O 4 :Cr 0.01 3+ (0≤y≤0.5). The blue shift and luminescent intensity variations of the charge transfer band and 3d-3d transitions in the spectra caused by Al substitution were related to larger band gap and stronger crystal field, respectively. The calculated crystal-field parameters indicated that Al incorporation enhanced the crystal field strength and induced more trigonal distortion due to different radii of Al 3+ and Ga 3+ .

  2. China’s Energy Transition in the Power and Transport Sectors from a Substitution Perspective

    Directory of Open Access Journals (Sweden)

    Shangfeng Han

    2017-04-01

    Full Text Available Facing heavy air pollution, China needs to transition to a clean and sustainable energy system, especially in the power and transport sectors, which contribute the highest greenhouse gas (GHG emissions. The core of an energy transition is energy substitution and energy technology improvement. In this paper, we forecast the levelized cost of electricity (LCOE for power generation in 2030 in China. Cost-emission effectiveness of the substitution between new energy vehicles and conventional vehicles is also calculated in this study. The results indicate that solar photovoltaic (PV and wind power will be cost comparative in the future. New energy vehicles are more expensive than conventional vehicles due to their higher manufacturer suggested retail price (MSRP. The cost-emission effectiveness of the substitution between new energy vehicles and conventional vehicles would be $96.7/ton or $114.8/ton. Gasoline prices, taxes, and vehicle insurance will be good directions for policy implementation after the ending of subsidies.

  3. The synthesis of no-carrier-added DL-4-[18F]fluorodeprenyl via the nucleophilic aromatic substitution reaction

    International Nuclear Information System (INIS)

    Plenevaux, Alain; Guillaume, Marcel

    1991-01-01

    No-carrier-added DL-α-methyl-β-4-[ 18 F]fluorophenyl-N-methyl-N-propynylethylamine (DL-4-[ 18 F]fluorodeprenyl) was synthesized via a 3-step procedure. The overall yield was 11%, the synthesis time was 90 min and the specific activity >0.57 Ci/μmol (end of synthesis). This synthesis approach, the conversion of an aromatic aldehyde to a homologous methyl ketone, extends the flexibility of the nucleophilic aromatic substitution reaction by applying it to the synthesis of radiotracers which do not bear electron-withdrawing activating groups on the aromatic ring. The tissue distribution of DL-4-[ 18 F]fluorodeprenyl in mice at 1, 10 and 50 min was also measured and showed that metabolic defluorination was not significant. Clearance or radioactivity from brain after injection of DL-4-[ 18 F]fluorodeprenyl was more rapid than that previously observed for [ 11 C]L-deprenyl. (author)

  4. Estimating intertemporal and intratemporal substitutions when both income and substitution effects are present: the role of durable goods

    Czech Academy of Sciences Publication Activity Database

    Pakoš, Michal

    2011-01-01

    Roč. 29, č. 3 (2011), s. 439-454 ISSN 0735-0015 Institutional research plan: CEZ:AV0Z70850503 Keywords : durable goods * intertemporal substitution * nonhomotheticity Subject RIV: AH - Economics Impact factor: 1.779, year: 2011

  5. Synthesis and biological activity of novel series of 4-methoxy, and 4,9-dimethoxy-5-substituted furo[2,3-g]-1,2,3-benzoxathiazine-7,7-dioxide derivatives.

    Science.gov (United States)

    El-Sawy, Eslam R; Ebaid, Manal S; Abo-Salem, Heba M; El-Hallouty, Salwa; Kassem, Emad M; Mandour, Adel H

    2014-05-01

    A novel series of 4-methoxy, and 4,9-dimethoxy-5-substituted furo[2,3-g]-1,2,3-benzoxathiazine-7,7-dioxide derivatives 3a,b, 10a-g and 11a-g were prepared in good yields via the reaction of 4-methoxy (1a) and 4,7-dimethoxy-5-acetyl-6-hydroxybenzofurans (1b) and their α,β-unsaturated keto derivatives 6a-g and 7a-g with chlorosulfonyl isocyanate (CSI). On the other hand, N-chlorosulfonyl carbamate derivatives 4a,b, 12a,b and 13a,b were prepared and allowed to react with piperidine to give the corresponding N-piperidinosulfonyl carbamate derivatives 5a,b, 14a,b and 15a,b, respectively. Sixteen new target compounds 3a,b, 10a-g, and 11a-g were tested for their DPPH radical-scavenging, and in vitro antiproliferative activity against A-549, MCF7 and HCT-116 cancer cell lines. Compounds 10a, 11c, 11e, and 11g showed moderate DPPH radical-scavenging activity compared to ascorbic acid at 100 μg/mL. 4,9-Dimethoxy-5-substituted styrylfuro[3,2-g]-1,2,3-benzoxathiazine-7,7-dioxides 11a, 11b, and 11c were found to be highly active against A-549 and HCT-116 cancer cell lines with IC50 values ranging from 0.02 to 0.08 μmol/mL compared to doxorubicin with IC50 = 0.04 and 0.06 μmol/mL, respectively.

  6. Synthesis of isochromene-type scaffolds via single-flask Diels-Alder-[4 + 2]-annulation sequence of a silyl-substituted diene with menadione.

    Science.gov (United States)

    Lee, Jihoon; Panek, James S

    2014-06-20

    A sequential Diels-Alder reaction/silicon-directed [4 + 2]-annulation was developed to assemble hydroisochromene-type ring systems from menadione 2. In the first step, a Diels-Alder of the 1-silyl-substituted butadiene 1 with 2 furnished an intermediate cyclic allylsilane. Subsequently, TMSOTf promoted a [4 + 2]-annulation through trapping of an oxonium, generated by condensation between an aldehyde and the TBS protected alcohol resulted in the formation of a cis-fused hydroisochromene 13.

  7. 2-Bromo-1,4-naphthoquinone: a potentially improved substitute of menadione in Apatone™ therapy

    Energy Technology Data Exchange (ETDEWEB)

    Graciani, F.S.; Ximenes, V.F. [Departamento de Química, Faculdade de Ciências, Universidade Estadual Paulista, Bauru SP (Brazil); Departamento de Análises Clínicas, Faculdade de Ciências Farmacêuticas, Universidade Estadual Paulista, Araraquara SP (Brazil)

    2012-05-18

    Apatone™, a combination of menadione (2-methyl-1,4-naphthoquinone, VK{sub 3}) and ascorbic acid (vitamin C, VC) is a new strategy for cancer treatment. Part of its effect on tumor cells is related to the cellular pro-oxidative imbalance provoked by the generation of hydrogen peroxide (H{sub 2}O{sub 2}) through naphthoquinone redox cycling. In this study, we attempted to find new naphthoquinone derivatives that would increase the efficiency of H{sub 2}O{sub 2} production, thereby potentially increasing its efficacy for cancer treatment. The presence of an electron-withdrawing group in the naphthoquinone moiety had a direct effect on the efficiency of H{sub 2}O{sub 2} production. The compound 2-bromo-1,4-naphthoquinone (BrQ), in which the bromine atom substituted the methyl group in VK{sub 3}, was approximately 10- and 19-fold more efficient than VK{sub 3} in terms of oxygen consumption and H{sub 2}O{sub 2} production, respectively. The ratio [H{sub 2}O{sub 2}]{sub produced} / [naphthoquinone]{sub consumed} was 68 ± 11 and 5.8 ± 0.2 (µM/µM) for BrQ and VK{sub 3}, respectively, indicating a higher efficacy of BrQ as a catalyst for the autoxidation of ascorbic acid. Both VK{sub 3} and BrQ reacted with glutathione (GSH), but BrQ was the more effective substrate. Part of GSH was incorporated into the naphthoquinone, producing a nucleophilic substitution product (Q-SG). The depletion of BrQ by GSH did not prevent its redox capacity since Q-SG was also able to catalyze the production of reactive oxygen species. VK{sub 3}/VC has already been submitted to clinical trials for the treatment of prostate cancer and has demonstrated promising results. However, replacement of VK{sub 3} with BrQ will open new lines of investigation regarding this approach to cancer treatment.

  8. Substituted hydroxyapatites for biomedical applications: A review

    Czech Academy of Sciences Publication Activity Database

    Šupová, Monika

    2015-01-01

    Roč. 41, č. 8 (2015), s. 9203-9231 ISSN 0272-8842 Institutional support: RVO:67985891 Keywords : bioapatite * calcium phosphate * hydroxyapatite * substitution Subject RIV: JJ - Other Materials Impact factor: 2.758, year: 2015

  9. Fat substitutes in processing of sausages using piramutaba waste.

    Science.gov (United States)

    de Fátima Henriques Lourenço, Lúcia; Dos Santos Galvão, Giane Célia; da Conceição Amaral Ribeiro, Suezilde; de Fátima Amaral Ribeiro, Carmelita; Park, Kil Jin

    2014-07-01

    The aim of this study was to evaluate fat substitute in processing of sausages prepared with surimi of waste from piramutaba filleting. The formulation ingredients were mixed with the fat substitutes added according to a fractional planning 2(4-1), where the independent variables, manioc starch (Ms), hydrogenated soy fat (F), texturized soybean protein (Tsp) and carrageenan (Cg) were evaluated on the responses of pH, texture (Tx), raw batter stability (RBS) and water holding capacity (WHC) of the sausage. Fat substitutes were evaluated in 11 formulations and the results showed that the greatest effects on the responses were found to Ms, F and Cg, being eliminated from the formulation Tsp. To find the best formulation for processing piramutaba sausage was made a complete factorial planning of 2(3) to evaluate the concentrations of fat substitutes in an enlarged range. The optimum condition found for fat substitutes in the sausages formulation were carrageenan (0.51%), manioc starch (1.45%) and fat (1.2%).

  10. Propagation of a finite bubble in a Hele-Shaw channel of variable depth

    Science.gov (United States)

    Juel, Anne; Franco-Gomez, Andres; Thompson, Alice; Hazel, Andrew

    2017-11-01

    We study the propagation of finite bubbles in a Hele-Shaw channel, where a centred rail is introduced to provide a small axially-uniform depth constriction. We demonstrate experimentally that this channel geometry can be used as a passive sorting device. Single air bubbles carried within silicone oil are generally transported on one side of the rail. However, for flow rates marginally larger than a critical value, a narrow band of bubble sizes on the order of the rail width can propagate over the rail, while bubbles of other sizes segregate to the side of the rail. The width of this band of bubble sizes increases with flow rate and the size of the most stable bubble can be tuned by varying the rail width. We present a depth-averaged theory which reveals that the mechanism relies on a non-trivial interaction between capillary and viscous forces that is fully dynamic, rather than being a simple modification of capillary static solutions. In contrast, for larger bubbles and sufficiently large imposed flow rates, we find that initially centred bubbles do not converge onto a steady mode of propagation. Instead they transiently explore weakly unstable steady modes, an evolution which results in their break-up and eventual settling into a steady state of changed topology. The financial support of CONICYT and the Leverhulme Trust are gratefully acknowledged.

  11. The role of annealing temperature and bio template (egg white) on the structural, morphological and magnetic properties of manganese substituted MFe2O4 (M=Zn, Cu, Ni, Co) nanoparticles

    Science.gov (United States)

    Ranjith Kumar, E.; Jayaprakash, R.; Kumar, Sanjay

    2014-02-01

    Manganese substituted ferrites (ZnFe2O4, CuFe2O4, NiFe2O4 and CoFe2O4) have been prepared in the bio template medium by using a simple evaporation method. The annealing temperature plays an important position on changing particle size and morphology of the mixed ferrite nanoparticles were found out by X-ray diffraction, transmission electron microscopy and scanning electron microscopy methods. The role of manganese substitution in the mixed ferrite nanoparticles were also analyzed for different annealing temperature. The substitution of Mn also creates a vital change in magnetic properties which is studied by using vibrating sample magnetometer (VSM). These spinel ferrites are decomposed to α-Fe2O3 after annealing above 550 °C in air. However, α-Fe2O3 phase was slowly vanished after ferrites annealing above 900 °C. The effect of this secondary phase on the structural change and magnetic properties of the mixed ferrite nanoparticles is discussed.

  12. Optimising the design of paramagnetic MRI contrast agents: influence of backbone substitution on the water exchange rate of Gd-DTPA derivatives.

    Science.gov (United States)

    Laurent, S; Botteman, F; Vander Elst, L; Muller, R N

    2004-04-01

    Among other factors influencing the residence time of the coordinated water (tauM) of paramagnetic contrast agents, the steric hindrance around the gadolinium ion seems to play a beneficial role. Such a crowding can be achieved by substituting the Gd-DTPA backbone on the C4 position. Several Gd-DTPA complexes carrying diverse groups at this position have thus been synthesised and characterised: GdS-C4-Me-DTPA, GdS-C4-n-Bu-DTPA, GdS-C4-iBu-DTPA, GdS-C4-iPr-DTPA, and Gd-C4-diMe-DTPA. TauM has been measured through the evolution of the water oxygen-17 transverse relaxation rate as a function of the temperature. The data show a reduction of tauM of GdS-C4-Me-DTPA, GdS-C4-n-Bu-DTPA, GdS-C4-iBu-DTPA, GdS-C4-iPr-DTPA, and Gd-C4-diMe-DTPA (tauM310 = 91,82, 108,98, and 57 ns respectively, as compared to Gd-DTPA (tauM310 = 143 ns)). At 310 K, the nuclear magnetic dispersion relaxation profiles of water protons are very similar for the five complexes which present longitudinal relaxivities slightly higher than those of Gd-DTPA. Regarding zinc transmetallation, C4-monosubstituted derivatives are more stable than Gd-DTPA. These results confirm that a judicious substitution of the DTPA skeleton allows for an acceleration of the coordinated water exchange rate. This observation can be useful for the design of vectorised contrast agents for molecular imaging. Copyright 2004 ESMRMB

  13. Immobilization of styrene-substituted 1,3,4-oxadiazoles into thermoreversible luminescent organogels and their unexpected photocatalyzed rearrangement.

    Science.gov (United States)

    Dumur, Frédéric; Contal, Emmanuel; Wantz, Guillaume; Phan, Trang N T; Bertin, Denis; Gigmes, Didier

    2013-01-21

    A series of styrene-substituted 1,3,4-oxadiazoles has been designed and investigated as new low-molecular-weight organogelators. The photophysical properties of the resulting thermoreversible organogels have been characterized by UV/Vis absorption and luminescence spectroscopies. Surprisingly, the gelation ability of the oxadiazoles depended on the presence of the styrene moiety as gelation of the investigated oxadiazoles did not take place in its absence. Gel formation was accompanied by a modification of the fluorescence of the organogelators in the supramolecular state. UV irradiation of the gels caused a rearrangement of the immobilized 1,3,4-oxadiazoles bearing a styrene moiety by a tandem [4+2] and [3+2] cascade reaction. Structure modification and color change of the gels were also evident upon irradiation. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. The effect of the substituted amphetamines, 2.4-methylenedioxymethamphetamine (MDMA) and P-methoxyamphetamine (PMA), on platelet aggregation

    International Nuclear Information System (INIS)

    Sluggett, A.J.; Irvine, R.J.; Bochner, F.; Rodgers, S.; Lloyd, J.V.

    2001-01-01

    Full text: Illicit substituted amphetamines such as 3,4-methylenedioxymethamphetamine (MDMA) and p-methoxyamphetamine (PMA) can cause severe toxicity. Disruption of normal coagulation mechanisms have been observed in most fatal cases. However, the precise mechanisms underlying these events are not clearly understood. MDMA and PMA are known to inhibit serotonin transporter function in the central nervous system (Daws et al 2000) and platelet serotonin transporter sites (Rudnick and Wall 1992). Serotonin is in high concentrations in platelets and activation of 5HT 2 receptors on the platelet surface potentiates aggregation of platelets. Therefore, we postulated that MDMA and PMA may have effects on coagulation via inhibition of normal platelet function. Human citrated platelets were incubated in the presence of MDMA (43- 435μM) or PMA (49-498μM) and their aggregator y response to a critical dose of adenosine diphosphate (ADP) determined. These responses were compared to the serotonin reuptake inhibitor fluoxetine (13-130μM). All 3 compounds were found to inhibit platelet aggregation. The IC50s for % aggregation at 5 minutes were MDMA 197μM ± 63μM PMA 344μM ±76μM and fluoxetine 24μM ±1 1μM (n=4). The effect of these drugs on the uptake of 14 C-5HT (0.9 μM /ml) into platelets was also determined and the IC50s observed were MDMA 62.3 μM ±11μM , PMA 24μM ±6μM and fluoxetine 2.5μM ± 0.6μM (n=4). The in vitro effects of MDMA and PMA on aggregation and uptake observed here are close to concentrations reported to have occurred in human fatalities. Therefore it is possible that direct effects of these drugs on coagulation mechanisms may contribute to the toxicity of these compounds. Copyright (2001) Australasian Society of Clinical and Experimental Pharmacologists and Toxicologists

  15. Effect of Honey as Partial Sugar Substitute on Pasting Properties ...

    African Journals Online (AJOL)

    The effect of partial substitution of sugar with liquid honey on the pasting properties of cooked dough made from cassava-wheat composite (10:90) flour as well as the sensory preference and shelf stability of its bread was investigated. Sucrose (S) in the bread recipe formulation was substituted with honey (H) at levels 0, 10, ...

  16. Description of Eimeria motelo sp. n. (Apicomplexa: Eimeriidae from the yellow footed tortoise, Geochelone denticulata (Chelonia: Testudinidae, and replacement of Eimeria carinii Lainson, Costa & Shaw, 1990 by Eimeria lainsoni nom. nov.

    Directory of Open Access Journals (Sweden)

    Lada Hurková

    2000-12-01

    Full Text Available Eimeria motelo sp. n. is described from faeces of the yellow-footed tortoise, Geochelone denticulata (L.. Oocysts are irregularly ellipsoidal or cylindrical, with slightly expressed lobed protrusions and irregularities at the poles, possibly caused by wrinkling of the oocyst wall, 17 (15-19 × 9.4 (8.5-11 µm, shape index (length/width being 1.81 (1.45-2. The oocyst wall is smooth, single-layered, 0.5 µm thick with no micropyle. There are no polar bodies. Sporocysts are ellipsoidal, 8.9 (7.5-10 × 4.4 (4-5 µm, shape index 2.03 (1.7-2.5. A sporocyst residuum is present, composed of many granules of irregular size. The sporozoites are elongate, lying lengthwise in the sporocysts. Comparison with other species of the genus Eimeria parasitising members of family Testudinidae indicates that the presently described coccidium represents a new species. The name of Eimeria carinii Lainson, Costa & Shaw, 1990 is found to be preoccupied by a homonym, Eimeria carinii Pinto 1928 given to a coccidium from Rattus norvegicus. Therefore, it is replaced by Eimeria lainsoni nom. nov.

  17. A Group Action Method for Construction of Strong Substitution Box

    Science.gov (United States)

    Jamal, Sajjad Shaukat; Shah, Tariq; Attaullah, Atta

    2017-06-01

    In this paper, the method to develop cryptographically strong substitution box is presented which can be used in multimedia security and data hiding techniques. The algorithm of construction depends on the action of a projective general linear group over the set of units of the finite commutative ring. The strength of substitution box and ability to create confusion is assessed with different available analyses. Moreover, the ability of resistance against malicious attacks is also evaluated. The substitution box is examined by bit independent criterion, strict avalanche criterion, nonlinearity test, linear approximation probability test and differential approximation probability test. This substitution box is equated with well-recognized substitution boxes such as AES, Gray, APA, S8, prime of residue, Xyi and Skipjack. The comparison shows encouraging results about the strength of the proposed box. The majority logic criterion is also calculated to analyze the strength and its practical implementation.

  18. Quasirelativistic calculation of 4s24p5, 4s24p44d and 4s4p6 configuration spectroscopic parameters for the W39+ ion

    International Nuclear Information System (INIS)

    Bogdanovich, P; Karpuškienė, R; Kisielius, R

    2015-01-01

    The ab initio quasirelativistic Hartree–Fock method developed specifically for the calculation of spectral parameters of heavy atoms and highly charged ions is used to derive spectral data for the 4s 2 4p 5 , 4s 2 4p 4 4d and 4s4p 6 configurations of the multicharged tungsten ion W 39+ . The relativistic effects are taken into account in the Breit–Pauli approximation for the quasirelativistic Hartree–Fock radial orbitals. The configuration interaction method is applied to include the electron correlation effects. Produced data are compared with existing experimental measurements and theoretical calculations. (paper)

  19. The hyperfine structure constants for the 4s24p and 4s25s states of Ga

    International Nuclear Information System (INIS)

    Wang Qingmin; Dong Chenzhong

    2012-01-01

    The hyperfine structure (hfs) constants for the states 4s 2 4p 2 P 1/2,3/2 and 4s 2 5s 2 S 1/2 of 71 Ga were calculated using the GRASP2K package based on the multiconfiguration Dirac-Fock (MCDF) method. The results indicated that the core polarization effect was important for the hyperfine structure constants. (authors)

  20. Enhanced osteoconductivity of sodium-substituted hydroxyapatite by system instability.

    Science.gov (United States)

    Sang Cho, Jung; Um, Seung-Hoon; Su Yoo, Dong; Chung, Yong-Chae; Hye Chung, Shin; Lee, Jeong-Cheol; Rhee, Sang-Hoon

    2014-07-01

    The effect of substituting sodium for calcium on enhanced osteoconductivity of hydroxyapatite was newly investigated. Sodium-substituted hydroxyapatite was synthesized by reacting calcium hydroxide and phosphoric acid with sodium nitrate followed by sintering. As a control, pure hydroxyapatite was prepared under identical conditions, but without the addition of sodium nitrate. Substitution of calcium with sodium in hydroxyapatite produced the structural vacancies for carbonate ion from phosphate site and hydrogen ion from hydroxide site of hydroxyapatite after sintering. The total system energy of sodium-substituted hydroxyapatite with structural defects calculated by ab initio methods based on quantum mechanics was much higher than that of hydroxyapatite, suggesting that the sodium-substituted hydroxyapatite was energetically less stable compared with hydroxyapatite. Indeed, sodium-substituted hydroxyapatite exhibited higher dissolution behavior of constituent elements of hydroxyapatite in simulated body fluid (SBF) and Tris-buffered deionized water compared with hydroxyapatite, which directly affected low-crystalline hydroxyl-carbonate apatite forming capacity by increasing the degree of apatite supersaturation in SBF. Actually, sodium-substituted hydroxyapatite exhibited markedly improved low-crystalline hydroxyl-carbonate apatite forming capacity in SBF and noticeably higher osteoconductivity 4 weeks after implantation in calvarial defects of New Zealand white rabbits compared with hydroxyapatite. In addition, there were no statistically significant differences between hydroxyapatite and sodium-substituted hydroxyapatite on cytotoxicity as determined by BCA assay. Taken together, these results indicate that sodium-substituted hydroxyapatite with structural defects has promising potential for use as a bone grafting material due to its enhanced osteoconductivity compared with hydroxyapatite. © 2013 Wiley Periodicals, Inc.

  1. Low Base-Substitution Mutation Rate in the Germline Genome of the Ciliate Tetrahymena thermophila

    Science.gov (United States)

    2016-09-15

    Tetrahymena thermophila, a model eukaryote. PLoS Biol. 4:e286. Farlow A, et al. 2015. The spontaneous mutation rate in the fission yeast Schizosaccharomyces...spontane- ous mutations in yeast . Proc Natl Acad Sci U S A. 105:9272–9277. Lynn DH, Doerder FP. 2012. The life and times of Tetrahymena. Methods Cell...Low Base-Substitution Mutation Rate in the Germline Genome of the Ciliate Tetrahymena thermophila Hongan Long1,2,y, David J. Winter3,*,y, Allan Y.-C

  2. Processing and electrical properties of gallium-substituted lead zirconate titanate ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Hajra, Sugato; Sharma, Pulkit; Rout, P.K. [Siksha O Anusandhan University, Department of Electrical and Electronics Engineering, Bhubaneswar (India); Sahoo, Sushrisangita; Choudhary, R.N.P. [Siksha O Anusandhan University, Department of Physics, Bhubaneswar (India)

    2017-12-15

    In the present paper, the effect of gallium (Ga) substitution on structural, microstructural, electrical conductivity of Pb(ZrTi)O{sub 3} (PZT) in the morphotropic phase boundary (MPB) region (i.e., Pb{sub 0.96}Ga{sub 0.04}(Zr{sub 0.48}Ti{sub 0.52}){sub 0.99}O{sub 3} (PGaZT-4)) was investigated. Increased grain density increases the resistivity of the Ga-modified PZT system. Preliminary structural analysis using X-ray diffraction pattern and data showed the existence of two phases [major tetragonal (T) and minor monoclinic (M)]. Field emission scanning electron micrograph (FESEM) showed the distribution of spherical as well as platelet type grains with small pores. The behavior of dielectric constant with temperature of PGaZT-4 exhibited the suppression of the ferroelectric phase transition [i.e., disappearance of Curie temperature (T{sub c})]. The complex impedance spectroscopy (CIS) technique helped to investigate the impedance parameters of PGaZT-4 in MPB region in a wide range of temperature (250-500 C) and frequency (1-1000 kHz) region. The impedance parameters of the material are found to be strongly dependent on frequency of AC electric field and temperature. The substitution of gallium at the Pb site of PZT generally enhances the dielectric constant and decreases loss tangent. The AC conductivity vs frequency (f = ω2π) in the region of dispersion follows the universal response of Jonscher's equation. Enhanced resistive characteristics were observed for Ga-substituted PZT in comparison to the pure PZT, which was well ensured from the studies of electrical parameters, such as impedance and AC conductivity. (orig.)

  3. 4-({[6-(4-Chlorobenzyl-4-methyl-5-oxo-4,5-dihydro-1,2,4-triazin-3-yl]sulfanyl}acetyl-3-phenylsydnone

    Directory of Open Access Journals (Sweden)

    Hoong-Kun Fun

    2011-04-01

    Full Text Available In the title syndone (1,2,3-oxadiazol-3-ylium-5-olate compound, C21H16ClN5O4S, the dihedral angle between the benzene and oxadiazole rings is 55.62 (11° and that between the triazine and the chloro-substituted phenyl rings is 82.45 (9°. There is an intramolecular C—H...S hydrogen bond, which generates an S(5 ring motif. In the crystal, inversion dimers linked by pairs of C—H...O hydrogen bonds generate R22(20 loops. The dimers are connected by C—H...N and C—H...O hydrogen bonds.

  4. Radiolabeled n-substituted-6-iodo-3, 14-dihydroxy-4, 5alpha-epoxymorphinans, intermediates for producing the same, and a process for the preparation and methods of detecting opioid receptors

    Energy Technology Data Exchange (ETDEWEB)

    de Costa, B.R.; Iadarola, M.J.; Rothman, R.B.; Berman, K.F.; Rice, K.C.

    1991-01-01

    The invention is directed to radiolabeled N-substituted-6-iodo-3,14-dihydroxy-4,5 alpha-epoxymorphinans, intermediates for producing the same, and a process for the preparation and methods of detecting opioid receptors, wherein Iodo is selected from the group consisting of (123)I and (125)I; and where the N substitution is alkyl, cycloalkylloweralkyl or allyl.

  5. Syntheses of Novel 4-Substituted N-(5-amino-1H-1,2,4-triazol-3-ylpyridine-3-sulfonamide Derivatives with Potential Antifungal Activity

    Directory of Open Access Journals (Sweden)

    Krzysztof Szafrański

    2017-11-01

    Full Text Available Candidiasis represent a serious threat for patients with altered immune responses. Therefore, we have undertaken the synthesis of compounds comprising a pyridine-3-sulfonamide scaffold and known antifungally active 1,2,4-triazole substituents. Thus a series of novel 4-substituted N-(5-amino-1H-1,2,4-triazol-3-ylpyridine-3-sulfonamides have been synthesized by multistep reactions starting from 4-chloropyridine-3-sulfonamide via N′-cyano-N-[(4-substitutedpyridin-3-ylsulfonyl]carbamimidothioates which were further converted with hydrazine hydrate to the corresponding 1,2,4-triazole derivatives 26–36. The final compounds were evaluated for antifungal activity against strains of the genera Candida, Geotrichum, Rhodotorula, and Saccharomycess isolated from patients with mycosis. Many of them show greater efficacy than fluconazole, mostly towards Candida albicans and Rhodotorula mucilaginosa species, with MIC values ≤ 25 µg/mL. A docking study of the most active compounds 26, 34 and 35 was performed showing the potential mode of binding to Candida albicans lanosterol 14α-demethylase. Also in vitro cytotoxicity of selected compounds have been evaluated on the NCI-60 cell line panel.

  6. Technical and allocative inefficiencies and factor elasticities of substitution. An analysis of energy waste in Iran's manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Khiabani, Nasser; Hasani, Karim [Department of Economics, Institute for Management and Planning Studies, Mokhtar Asgari Str.10, 19395, Tehran (Iran, Islamic Republic of)

    2010-09-15

    Ignoring technical and allocative inefficiencies or embedding one of them alone in a system of input demands may result in biased elasticities. We consider a comprehensive model including technical inefficiency (in input and output forms) and allocative inefficiency and apply it to panel data from Iran's manufacturing sector. The results show that the presence of both inefficiencies affects the computed elasticities of demand and substitution. Moreover, in spite of current waste of energy in Iran's manufacturing, the elimination of environmental constraints will prompt the manufacturing firms to increase the utilization of energy relative to both capital and labor. (author)

  7. Alkyl Substitution Effect on Oxidation Stability of Sulfone-Based Electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Su, Chi-Cheung [Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 S. Cass Ave. Argonne IL 60439 USA; He, Meinan [Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 S. Cass Ave. Argonne IL 60439 USA; Redfern, Paul [Materials Science Division, Argonne National Laboratory, 9700 S. Cass Ave. Argonne IL 60439 USA; Curtiss, Larry A. [Materials Science Division, Argonne National Laboratory, 9700 S. Cass Ave. Argonne IL 60439 USA; Liao, Chen [Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 S. Cass Ave. Argonne IL 60439 USA; Zhang, Lu [Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 S. Cass Ave. Argonne IL 60439 USA; Burrell, Anthony K. [Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 S. Cass Ave. Argonne IL 60439 USA; Zhang, Zhengcheng [Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 S. Cass Ave. Argonne IL 60439 USA

    2016-02-16

    Organic sulfone compounds have been widely used as high-voltage electrolytes for lithium-ion batteries for decades. However, owing to the complexity of the synthesis of new sulfones, only a few commercially available sulfones have been studied. In this paper, we report the synthesis of new sulfone compounds with various substituent groups and the impact of the substituent group on the oxidation stability of sulfones. Electrochemical floating tests using a 5 V LiNi0.5Mn1.5O4 spinel cathode and density functional theory calculations showed that the cyclopentyl-substituted sulfone McPS suffered from oxidation instability, starting from 4.9 V versus Li+/Li, as observed by the large leakage currents. On the other hand, the isopropyl-substituted sulfone MiPS and tetramethylene substituted sulfone TMS showed much improved oxidation stability under identical testing conditions. The substitution structure of the sulfone plays a significant role in the determination of its oxidative stability and should first be considered for the development of new sulfone-based electrolytes for high-voltage, high-energy lithium-ion batteries.

  8. Structural, electrical, magnetic and dielectric properties of rare-earth substituted cobalt ferrites nanoparticles synthesized by the co-precipitation method

    Energy Technology Data Exchange (ETDEWEB)

    Nikumbh, A.K., E-mail: aknik@chem.unipune.ac.in; Pawar, R.A.; Nighot, D.V.; Gugale, G.S.; Sangale, M.D.; Khanvilkar, M.B.; Nagawade, A.V.

    2014-04-15

    Pure nanoparticles of the rare-earth substituted cobalt ferrites CoRE{sub x}Fe{sub 2−x}O{sub 4} (where RE=Nd, Sm and Gd and x=0.1 and 0.2) were prepared by the chemical co-precipitation method. X-ray diffraction, Transmission electron microscopy (TEM), d.c. electrical conductivity, Magnetic hysteresis and Thermal analysis are utilized in order to study the effect of variation in the rare-earth substitution and its impact on particle size, magnetic properties like M{sub S}, H{sub C} and Curie temperature. The phase identification of the materials by X-ray diffraction reveals the single-phase nature of the materials. The lattice parameter increased with rare-earth content for x≤0.2. The Transmission electron micrographs of Nd-, Sm- and Gd-substituted CoFe{sub 2}O{sub 4} exhibit the particle size 36.1 to 67.8 nm ranges. The data of temperature variation of the direct current electrical conductivity showed definite breaks, which corresponds to ferrimagnetic to paramagnetic transitions. The thermoelectric power for all compound are positive over the whole range of temperature. The dielectric constant decreases with frequency and rare-earth content for the prepared samples. The magnetic properties of rare-earth substituted cobalt ferrites showed a definite hysteresis loop at room temperature. The reduction of coercive force, saturation magnetization, ratio M{sub R}/M{sub S} and magnetic moments may be due to dilution of the magnetic interaction.

  9. [The substitution effect of leadership substitutes for transformational leadership in nursing organization].

    Science.gov (United States)

    Kim, Jeong-Hee

    2006-04-01

    This paper was conducted to examine the effects of transformational leadership behaviors, within the substitutes for leadership model (Kerr & Jermier, 1978). Data was collected from 181 staff nurses in 3 general hospitals, with self-reporting questionnaires (MLQ developed by Bass, rd-SLS developed by Podsakoff, et al., and MSQ developed by Weiss, et al.). Descriptive statistics, factor analysis, Cronbach's alpha and moderated regression analysis were used. 1) The transformational leader behaviors and substitutes for leadership each had correlations with job satisfaction. 2) The total amount of variance accounted for by the substitutes for leadership was substantially greater than by the transformational leadership behaviors. 3) Few of the substitutes variables moderated the relationships between the transformational leader behaviors and job satisfaction in a manner consistent with that specified by Howell, Dorfman, and Kerr (1986). The finding of this study suggest that leaders need to have a better understanding of those contextual variables that influence job satisfaction. Thus future research should focus attention on the moderating effects of substitutes, as well as the things that leaders can do to influence them. In addition, it may be good to examine the effects of substitutes on other criterion variables.

  10. Structural, morphological and magnetic properties variation of nickel-manganese ferrites with lithium substitution

    International Nuclear Information System (INIS)

    Momin, A.A.; Parvin, Roksana; Akther Hossain, A.K.M.

    2017-01-01

    Mixed ferrites with nominal chemical compositions Li_xNi_0_._2Mn_0_._8_−_2_xFe_2_+_xO_4 ranging from x=0 to 0.4 in the steps of 0.1 have been prepared by the auto combustion technique. The X-ray diffraction patterns consist of major cubic spinel Li_xNi_0_._2Mn_0_._8_−_2_xFe_2_+_xO_4 phase with minor impurity phases (Fe_2O_3 and MnO) and with Li substitution phase purity has increased, such that for x=0.4 pure phase spinel structure has been obtained. The lattice parameter has decreased with the increase in Li content obeying Vegard’s law. Both the bulk density and theoretical density have decreased with Li content and with sintering temperature (T_s) up to 1300 °C ρ_B has increased and beyond that it has decreased. Morphological studies have performed by a high resolution optical microscope and observed that average grain size noticeably dependent on Li substitution. The initial permeability (μ_i′′) has found to decrease with Li substitution. The Curie temperature (T_C) has determined from the temperature dependent μ_i′′ and found to increases with Li content. From the room temperature magnetization measurement, it has observed that all samples are in ferrimagnetic state at room temperature. The number of Bohr magneton has been obtained from the observed saturation magnetization. Dielectric constant, dielectric loss tangent, ac conductivity and complex impedance are studied in the frequency range 20 Hz–10 MHz. Frequency dependence of dielectric constant in lower frequencies indicates a usual dielectric dispersion due to the Maxwell-Wagner type interfacial polarization. Dielectric loss tangent shows similar behavior like dielectric constant. The complex impedance analysis has been used to study the effect of grain and grain boundary on the electrical properties and with Li content both grain and grain boundary resistance show an increasing trend. The ac conductivity shows frequency independent behavior at the low frequency side and with

  11. Autonomy and Substitute Decision-Making with People with Intellectual Disabilities. Ethical Perspective

    OpenAIRE

    Xabier ETXEBERRIA MAULEON

    2016-01-01

    The text deals with the existing ethical tension between decision-making on behalf of people with intellectual disabilities and substitute decision-making, and the duty-bound respect for the person’s autonomy. The work begins by distinguishing decision- making on behalf of someone and substitute decision-making, consequently favoring the latter, as well as relating autonomy to interdependence. This first clarification leads to the construction of a basic and general criterion for substitute d...

  12. Synthesis of Novel Homo-N-Nucleoside Analogs Composed of a Homo-1,4-Dioxane Sugar Analog and Substituted 1,3,5-Triazine Base Equivalents

    Directory of Open Access Journals (Sweden)

    Qiang Yu

    2008-12-01

    Full Text Available Enantioselective syntheses from dimethyl tartrate of 1,3,5-triazine homo-N-nucleoside analogs, containing a 1,4-dioxane moiety replacing the sugar unit in natural nucleosides, were accomplished. The triazine heterocycle in the nucleoside analogs was further substituted with combinations of NH2, OH and Cl in the 2,4-triazine positions.

  13. WAr on DrugS

    African Journals Online (AJOL)

    2009-04-12

    Apr 12, 2009 ... ABStrAct. Since drugs became both a public and social issue in Nigeria, fear about both the real and .... drugs as being morally reprehensible, and ..... tice system (see for instance, Shaw, 1995; ..... A cut throat business:.

  14. Substituent effects on mono-substituted and poly-substituted nitriles; Efeitos dos substituintes em nitrilas mono- e polissubstituidas

    Energy Technology Data Exchange (ETDEWEB)

    Sofia, Raquel C.R.; Carneiro, Paulo I.B.; Rittner, Roberto [Universidade Estadual de Campinas, SP (Brazil). Inst. de Quimica; Fabi, Marino T [Rhodia S.A., Sao Paulo, SP (Brazil)

    1992-12-31

    This work studies various mono substituted aliphatic nitriles, Y C H{sub 2} (Y=H, F, Cl, Br, I, OMe, S Me, SEt{sub 2}, Me and Ph), and some reference nitriles (Y=Et, n-Pr, n-Bu, n-Am, n-Hex and n-Hept) 12 refs., 3 tabs.

  15. Substitution determination of Fmoc‐substituted resins at different wavelengths

    Science.gov (United States)

    Kley, Markus; Bächle, Dirk; Loidl, Günther; Meier, Thomas; Samson, Daniel

    2017-01-01

    In solid‐phase peptide synthesis, the nominal batch size is calculated using the starting resin substitution and the mass of the starting resin. The starting resin substitution constitutes the basis for the calculation of a whole set of important process parameters, such as the number of amino acid derivative equivalents. For Fmoc‐substituted resins, substitution determination is often performed by suspending the Fmoc‐protected starting resin in 20% (v/v) piperidine in DMF to generate the dibenzofulvene–piperidine adduct that is quantified by ultraviolet–visible spectroscopy. The spectrometric measurement is performed at the maximum absorption wavelength of the dibenzofulvene–piperidine adduct, that is, at 301.0 nm. The recorded absorption value, the resin weight and the volume are entered into an equation derived from Lambert–Beer's law, together with the substance‐specific molar absorption coefficient at 301.0 nm, in order to calculate the nominal substitution. To our knowledge, molar absorption coefficients between 7100 l mol−1 cm−1 and 8100 l mol−1 cm−1 have been reported for the dibenzofulvene–piperidine adduct at 301.0 nm. Depending on the applied value, the nominal batch size may differ up to 14%. In this publication, a determination of the molar absorption coefficients at 301.0 and 289.8 nm is reported. Furthermore, proof is given that by measuring the absorption at 289.8 nm the impact of wavelength accuracy is reduced. © 2017 The Authors Journal of Peptide Science published by European Peptide Society and John Wiley & Sons Ltd. PMID:28635051

  16. Electronic and magnetic properties of SnS2 monolayer doped with 4d transition metals

    Science.gov (United States)

    Xiao, Wen-Zhi; Xiao, Gang; Rong, Qing-Yan; Chen, Qiao; Wang, Ling-Ling

    2017-09-01

    We investigate the electronic structures and magnetic properties of SnS2 monolayers substitutionally doped with 4-d transition-metal through systematic first principles calculations. The doped complexes exhibit interesting electronic and magnetic behaviors, depending on the interplay between crystal field splitting, Hund's rule, and 4d levels. The system doped with Y is nonmagnetic metal. Both the Zr- and Pd-doped systems remain nonmagnetic semiconductors. Doping results in half-metallic states for Nb-, Ru-, Rh-, Ag, and Cd doped cases, and magnetic semiconductors for systems with Mo and Tc dopants. In particular, the Nb- and Mo-doped systems display long-ranged ferromagnetic ordering with Curie temperature above room temperature, which are primarily attributable to the double-exchange mechanism, and the p-d/p-p hybridizations, respectively. Moreover, The Mo-doped system has excellent energetic stability and flexible mechanical stability, and also possesses remarkable dynamic and thermal (500 K) stability. Our studies demonstrate that Nb- and Mo-doped SnS2 monolayers are promising candidates for preparing 2D diluted magnetic semiconductors, and hence will be a helpful clue for experimentalists.

  17. Quaternary sulphides Cu2Zn(Ti, Zr, Hf)S4, the new type of photovoltaic materials%四元硫化物Cu2Zn(Ti,Zr,Hf)S4:一类新颖光伏材料∗

    Institute of Scientific and Technical Information of China (English)

    范巍; 曾雉

    2016-01-01

    采用第一性原理电子结构方法研究了四价过渡金属Ti, Zr和Hf替代Cu2ZnSnS4(CZTS)中Sn原子以及Se替代S原子所得到的四元硫族化合物的电子结构、光学性质和晶体结构的稳定性。实验上用Se替代CZTS中部分S得到的Cu2ZnSnS4−xSex(CZTSSe)作为光吸收材料,可以进一步提高光伏效率。我们计算表明用Se替代S后, CZTSe的价带顶明显下移,并接近Cu(In, Ga) Se2(CIGS)价带顶位置。与CZTSe的电子结构特征一样, Cu2Zn(Ti, Zr, Hf)S4四元硫化物的价带顶与母体材料CZTS相比也向低能移动,并接近CIGS价带顶位置。由于高光伏效率要求窗口材料ZnO、缓冲层材料和光吸收材料的价带顶和带隙满足一定的渐进的变化关系,因此可以预见用Cu2Zn(Ti, Zr, Hf)S4作光吸收材料可以有效地提高甚至接近CIGS的光伏效率。通过计算弹性常数和声子谱,以及有限温度下第一性原理分子动力学模拟,发现Cu2Zn(Ti, Zr, Hf)S4的结构稳定性与CZTS相近。进一步计算Cu2Zn(Ti, Zr, Hf)S4与不同缓冲层间和窗口材料与缓冲层间的反射系数,并讨论了ZnSe, In2S3, ZnS作为缓冲层材料和TiO2作为窗口材料对光伏效率可能的影响。%Based on the first-principles electronic-structure method, we study the electronic structures, optical properties, and the structural stabilities of the quaternary sulphides Cu2Zn(Ti, Zr, Hf) S4, which are obtained via substituting Ti, Zr, and Hf elements for Sn elements in Cu2ZnSnS4 (CTZS). It is well known that the photovoltaic efficiency of CZTS(Se) will be improved if the Se atoms partially substitute S atoms in CZTS. Our results show that the valence-band top of CZTSe shifts to lower energy and accesses to the valence-band top of Cu(InGa) Se2 (CIGS). Similar to CZTSe, the valence-band tops of Cu2Zn(Ti, Zr, Hf)S4 also shift to lower energies and access to the top of valence-band of CIGS. The high photovoltaic efficiency requires the smooth changes of the

  18. S3b amino acid substitutions and ancillary subunits alter the affinity of Heteropoda venatoria toxin 2 for Kv4.3.

    Science.gov (United States)

    DeSimone, Christopher V; Lu, YiChun; Bondarenko, Vladimir E; Morales, Michael J

    2009-07-01

    Heteropoda venatoria toxin 2 (HpTx2) is an inhibitor cystine knot (ICK)-gating modifier toxin that selectively inhibits Kv4 channels. To characterize the molecular determinants of interaction, we performed alanine scanning of the Kv4.3 S3b region. HpTx2-Kv4.3 interaction had an apparent K(d) value of 2.3 microM. Two alanine mutants in Kv4.3 increased K(d) values to 6.4 microM for V276A and 25 microM for L275A. Simultaneous mutation of both amino acids to alanine nearly eliminated toxin interaction. Unlike Hanatoxin and other well characterized ICK toxins, HpTx2 binding does not require a charged amino acid for interaction. To determine whether the identity of the S3b binding site amino acids altered HpTx2 specificity, we constructed Kv4.3 [LV275IF]. This mutation decreased the K(d) value to 0.54 microM, suggesting that the hydrophobic character of the putative binding site is the most important property for interaction with HpTx2. One mutant, N280A, caused stronger interaction of HpTx2 with Kv4.3; the K(d) value for Kv4.3 [N280A] was 0.26 microM. To understand Kv4.3-based transient outward currents in native tissues, we tested the affinity of HpTx2 for Kv4.3 coexpressed with KChIP2b. The toxin's K(d) value for Kv4.3 + KChIP2b was 0.95 microM. KChIP2b stabilizes the closed state of Kv4.3, suggesting that the increased toxin affinity is due to increased stabilization of the closed state. These data show that HpTx2 binding to Kv4.3 has aspects in common with other ICK gating modifier toxins but that the interventions that increase toxin affinity suggest flexibility toward channel binding that belies its unusual specificity for Kv4 channels.

  19. Synthesis, characterization and modelling of zinc and silicate co-substituted hydroxyapatite.

    Science.gov (United States)

    Friederichs, Robert J; Chappell, Helen F; Shepherd, David V; Best, Serena M

    2015-07-06

    Experimental chemistry and atomic modelling studies were performed here to investigate a novel ionic co-substitution in hydroxyapatite (HA). Zinc, silicate co-substituted HA (ZnSiHA) remained phase pure after heating to 1100 °C with Zn and Si amounts of 0.6 wt% and 1.2 wt%, respectively. Unique lattice expansions in ZnSiHA, silicate Fourier transform infrared peaks and changes to the hydroxyl IR stretching region suggested Zn and silicate co-substitution in ZnSiHA. Zn and silicate insertion into HA was modelled using density functional theory (DFT). Different scenarios were considered where Zn substituted for different calcium sites or at a 2b site along the c-axis, which was suspected in singly substituted ZnHA. The most energetically favourable site in ZnSiHA was Zn positioned at a previously unreported interstitial site just off the c-axis near a silicate tetrahedron sitting on a phosphate site. A combination of experimental chemistry and DFT modelling provided insight into these complex co-substituted calcium phosphates that could find biomedical application as a synthetic bone mineral substitute. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  20. SO2 policy and input substitution under spatial monopoly

    International Nuclear Information System (INIS)

    Gerking, Shelby; Hamilton, Stephen F.

    2010-01-01

    Following the U.S. Clean Air Act Amendments of 1990, electric utilities dramatically increased their utilization of low-sulfur coal from the Powder River Basin (PRB). Recent studies indicate that railroads hauling PRB coal exercise a substantial degree of market power and that relative price changes in the mining and transportation sectors were contributing factors to the observed pattern of input substitution. This paper asks the related question: To what extent does more stringent SO 2 policy stimulate input substitution from high-sulfur coal to low-sulfur coal when railroads hauling low-sulfur coal exercise spatial monopoly power? The question underpins the effectiveness of incentive-based environmental policies given the essential role of market performance in input, output, and abatement markets in determining the social cost of regulation. Our analysis indicates that environmental regulation leads to negligible input substitution effects when clean and dirty inputs are highly substitutable and the clean input market is mediated by a spatial monopolist. (author)

  1. Eosin-sensitized photooxidation of substituted phenylalanines and tyrosines

    Energy Technology Data Exchange (ETDEWEB)

    Rizzuto, F.; Spikes, J.D.

    1977-01-01

    The cosin-sensitized photooxidation of tyrosine and a number of compounds related to tyrosine (substituted phenylalanines) was studied by steady-state kinetic and flash photolysis techniques. In particular, the role of the phenolic group and the amino and carboxyl groups of the alanyl side chain in the photooxidation mechanism was investigated in detail. Several relationships between substrate structure and susceptibility to photooxidation as well as effects of substrate structure on photooxidation mechanisms were found. For example, phenylalanine is not photooxidizable, but substitution of electron-donating (activating) groups such as -OH (as in tyrosine) or -NH/sub 2/ (as in p-aminophenylalanine) results in rapidly photooxidized derivatives. However, substituting deactivating groups such as -Cl (as in p-chlorophenylalanine) or weakly activating groups such as -OCH/sub 3/ (as in 4-methoxyphenylalanine) result in non-photooxidizable derivatives. Substitution of additional activating groups to the ring of hydroxy-substituted phenylalanines results in increased rates of photooxidation, whereas additional deactivating groups result in decreased photooxidation rates. The rate-determining step in the photooxidation mechanism is shown to be dependent on the presence and position of an electron-donating substituent on the benzenoid ring. Only minor involvement of the side chain amino and carboxyl groups was found. Both singlet oxygen and hydrogen abstraction mechanisms are involved in the eosin-sensitized photooxidation of hydroxy-substituted phenylalanines (e.g., tyrosine). The hydrogen abstraction mechanism probably predominates at both pH 8 and 11.

  2. Hydrogen bonding in (substituted benzene)·(water)n clusters with n≤4

    International Nuclear Information System (INIS)

    Barth, H.-D.; Buchhold, K.; Djafari, S.; Reimann, B.; Lommatzsch, U.; Brutschy, B.

    1998-01-01

    Infrared ion-depletion spectroscopy, a double resonance method combining vibrational predissociation with resonant two-photon ionization (R2PI) spectroscopy, has been applied to study mixed clusters of the type (substituted benzene)·(H 2 O) n with n≤4. The UV chromophores were p-difluorobenzene, fluorobenzene, benzene, toluene, p-xylene and anisole. From the IR depletion spectra in the region of the OH stretching vibrations it could be shown that the water molecules are attached as subclusters to the chromophores. Size and configuration of the subclusters could be deduced from the IR depletion spectra. In the anisole·(H 2 O) 1 a nd 2 complexes the water clusters form an ordinary hydrogen bond to the oxygen atom of the methoxy group. In all other mixed complexes a π-hydrogen bond is formed between one of the free OH groups of a water subcluster and the π-system of the chromophore. According to the strength of this interaction the frequency of the respective absorption band exhibits a characteristic red-shift which could be related to the total atomic charges in the aromatic ring. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  3. Electron excitation cross sections for the 2s(2)2p(3)4S(O) -- 2s(2)2p(3)2D(O) (forbidden) and 4S(O) -- 2s2p(4) 4P (resonance) transitions in O II

    Science.gov (United States)

    Zuo, M.; Smith, Steven J.; Chutjian, A.; Williams, I. D.; Tayal, S. S.; Mclaughlin, Brendan M.

    1995-01-01

    Experimental and theoretical excitation cross sections are reported for the first forbidden transition 4S(O) -- 2S(2)2p(3) 2D(O) (lambda-lambda 3726, 3729) and the first allowed (resonance) transition 4S(O) -- 2s2p(4) 4P(lambda-833) in O II. Use is made of electron energy loss and merged-beams methods. The electron energy range covered is 3.33 (threshold) to 15 eV for the S -- D transition, and 14.9 (threshold) to 40 eV for the S -- P transition. Care was taken to assess and minimize the metastable fraction of the O II beam. An electron mirror was designed and tested to reflect inelastically backscattered electrons into the forward direction to account for the full range of polar scattering angles. Comparisons are made between present experiments and 11-state R-matrix calculations. Calculations are also presented for the 4S(O) -- 2s(2)2p(3)2P(O) (lambda-2470) transition.

  4. Molecular complexes of L-phenylalanine with substituted 1,4-benzoquinones in aqueous medium: Spectral and theoretical investigations

    Science.gov (United States)

    Ganesh, K.; El-Mossalamy, E. H.; Satheshkumar, A.; Balraj, C.; Elango, K. P.

    2013-12-01

    Various spectral techniques such as UV-Vis, FT-IR, and fluorescence have been employed to investigate the charge transfer interaction of L-phenylalanine (LPA) with substituted 1,4-benzoquinones (MQ1-4). Kinetic and thermodynamic properties of the complexes were determined in aqueous medium at physiological condition (pH = 7). The interaction of MQ1-4 with L-phenylalanine (LPA) was found to proceed through the formation of donor-acceptor complex, yielding a radical anion. The stoichiometry of the complexes was determined by Jobs continuous variation method and was found to be 1:1 in all the cases. Fluorescence quenching studies showed that the interaction between the donor and the acceptors is spontaneous. The results indicated that the progressive replacement of chlorine atom (-I effect) by methoxy group (+M effect) in the quinone decreased the electron acceptor property of the quinone. The order of the experimentally measured association constant of these complexes was well supported by DFT/B3LYP calculations.

  5. Synthesis, characterization and pharmacological evaluation of substituted phenoxy acetamide derivatives

    Directory of Open Access Journals (Sweden)

    Rani Priyanka

    2015-01-01

    Full Text Available A novel series of 2-(substituted phenoxy-N-(1,7,7-trimethylbicyclo[2.2.1]heptan-2-ylacetamide and N-(2-bromocyclohexyl-2-(substituted phenoxyacetamide derivatives having cyclohexyl nucleus as common in both types were synthesized and assessed for their anti-inflammatory activity by a carrageenan induced rat paw oedema method, analgesic activity by Eddy’s hot plate method and antipyretic activity by brewer’s yeast induced pyrexia method. All the novel derivatives have been synthesized by the reaction of camphor and similar ketone having cyclohexane nucleus (e.g. 2-bromocyclohexanone with ammonium carbonate and formic acid resulting in the formation of aromatic amines (1a-b. These amines on further chloroacetylation with chloroacetylchloride give compounds (2a-b. Compounds (2a-b are converted to 2-(substituted phenoxy-N-(1,7,7-trimethylbicyclo[2.2.1]heptan-2-yl acetamide and N-(2-bromocyclohexyl-2-(substituted phenoxyacetamide derivatives on treatment with substituted phenol. Among the series 3a-f, 3i, 3k, 3l compounds showed significant anti-inflammatory activity as compared to the standard drug diclofenac sodium and also compound 3a-f, 3h, 3j, 3k exhibit significant analgesic activity as compared to the standard drug. Compounds 3a-f and 3k showed antipyretic activity nearly to the standard drug indomethacin. Compounds 3a-f and 3k possess anti-inflammatory, analgesic and antipyretic activities near to the standard.

  6. A microwave-catalyzed rapid, efficient and ecofriendly synthesis of substituted pyrazol-5-ones

    Directory of Open Access Journals (Sweden)

    RAHUL P. GAVANDE

    2003-10-01

    Full Text Available A series of 1-(3,4-dihydro-3-oxo-2H-1,4-benzoxazine-2-carbonyl-3-methyl-4-(substituted phenylhydrazono-2-pyrazolin-5-ones have been synthesized by the reaction of 2H-3,4-dihydro-3-oxo-1,4-benzoxazine-2-carboxylic acid hydrazide with substituted acetoacetic ester derivatives using acetic acid as solvent under microwave irradiation (MWI, as well as by conventional methods. The reaction rate is enhanced tremendously and the yields are improved under MWI as compared to conventional methods.

  7. Influence of diluent alkyl substitution on the extraction of Am(III) and Eu(III) by a 6,6'-bis(1,2,4-triazin-3-yl)-2,2'-bipyridine ligand dissolved in alkylated cyclohexanone diluents

    International Nuclear Information System (INIS)

    Distler, P.; Spendlikova, I.; John, J.; Czech Technical Univ., Prague; Harwood, L.M.; Hudson, M.J.; Lewis, F.W.

    2012-01-01

    Several alkylated cyclohexanones were investigated as potential diluents for the selective extraction of Am(III) from Eu(III) from nitric acid solutions by the CyMe 4 -BTBP ligand. No significant extraction of either of the metal ions was observed for these diluents themselves. In the extractions from 1 M HNO 3 , 3-methylcyclohexanone and 4-methylcyclohexanone gave comparable results to cyclohexanone whereas in the extractions from 4 M HNO 3 , 2-methylcyclohexanone, 3-methylcyclohexanone and 4-methylcyclohexanone all gave superior results. For the monomethylated diluents, D Am and SF Am/Eu decreased in the order of alkyl substitution 2 > 4 ∝ 3. However, alkyl substitution of cyclohexanone significantly slows down the extraction kinetics compared to cyclohexanone, and the position of alkyl substitution was found to play an important role in the solvents properties. 3-Methylcyclohexanone was identified as the most promising of the diluents. (orig.)

  8. Substitution determination of Fmoc-substituted resins at different wavelengths.

    Science.gov (United States)

    Eissler, Stefan; Kley, Markus; Bächle, Dirk; Loidl, Günther; Meier, Thomas; Samson, Daniel

    2017-10-01

    In solid-phase peptide synthesis, the nominal batch size is calculated using the starting resin substitution and the mass of the starting resin. The starting resin substitution constitutes the basis for the calculation of a whole set of important process parameters, such as the number of amino acid derivative equivalents. For Fmoc-substituted resins, substitution determination is often performed by suspending the Fmoc-protected starting resin in 20% (v/v) piperidine in DMF to generate the dibenzofulvene-piperidine adduct that is quantified by ultraviolet-visible spectroscopy. The spectrometric measurement is performed at the maximum absorption wavelength of the dibenzofulvene-piperidine adduct, that is, at 301.0 nm. The recorded absorption value, the resin weight and the volume are entered into an equation derived from Lambert-Beer's law, together with the substance-specific molar absorption coefficient at 301.0 nm, in order to calculate the nominal substitution. To our knowledge, molar absorption coefficients between 7100 l mol -1  cm -1 and 8100 l mol -1  cm -1 have been reported for the dibenzofulvene-piperidine adduct at 301.0 nm. Depending on the applied value, the nominal batch size may differ up to 14%. In this publication, a determination of the molar absorption coefficients at 301.0 and 289.8 nm is reported. Furthermore, proof is given that by measuring the absorption at 289.8 nm the impact of wavelength accuracy is reduced. © 2017 The Authors Journal of Peptide Science published by European Peptide Society and John Wiley & Sons Ltd. © 2017 The Authors Journal of Peptide Science published by European Peptide Society and John Wiley & Sons Ltd.

  9. Electricity/oil substitution

    International Nuclear Information System (INIS)

    Melvin, J.G.

    1980-09-01

    The extent to which electricity could substitute for imported oil in Canada is assessed and it is concluded that the bulk of projected oil imports could be displaced. This substitution of electricity for oil could be largely completed within two decades, with existing technology, using Canadian resources. The substitution of electricity for imported oil would result in relatively low energy costs and would stimulate economic growth. Energy self-sufficiency through the substitution of electricity for oil is uniquely a Canadian option; it is not open to other industrial countries. The option exists because of Canada's resources of oil sands for essential liquid fuels, hydraulic and nuclear electrical potential, and natural gas as an interim source of energy. While other countries face an energy crisis due to declining supplies of oil, Canada faces opportunities. The policies of Federal and Provincial governments, as perceived by individual decision makers, will have a major influence on Canada's ability to realize opportunities. (auth)

  10. Growth-direction dependence of steady-state Saffman-Taylor flow in an anisotropic Hele-Shaw cell

    International Nuclear Information System (INIS)

    McCloud, K.V.; Maher, J.V.

    1996-01-01

    Selection of steady-state fingers has been measured in a Hele-Shaw cell perturbed by having a square lattice etched onto one of the plates. Flows at different orientations θ between the direction of flow and the lattice axes have been studied, in a wide range of observable tip velocities where the perturbation was made microscopic in the sense that the capillary length of the flow was much greater than the etched lattice cell size. The full range of dynamically interesting angles for the square lattice was examined, and above a threshold, the microscopic perturbation always results in wider fingers than are selected in the unperturbed case. There is some dependence of the width of the fingers on the orientation of the flow, with fingers at θ=0 degree being the widest with respect to the unperturbed fingers, and fingers at 45 degree being the least wide, although still wider than the unperturbed fingers. All observed solutions are symmetric, centered in the channel, and have the relation between tip-curvature and finger width expected of members of the Saffman-Taylor family of solutions. Selected solutions narrow again at tip velocities where the perturbation can no longer be considered microscopic. copyright 1996 The American Physical Society

  11. Preparation and physical characteristics of a lithium-beryllium-substituted fluorapatite

    International Nuclear Information System (INIS)

    Lexa, D.

    1999-01-01

    A lithium-beryllium-substituted fluorapatite, Li 0.50 Be 0.25 Ca 4.50 (PO 4 ) 3 F, has been prepared by means of a high-temperature reaction between lithium beryllium fluoride, Li 2 BeF 4 , and tricalcium phosphate, Ca 3 (PO 4 ) 2 . This material has potential application as a waste form for radioactive and toxic fluoride salts. Monitoring of the reaction progress by differential scanning calorimetry indicated that the reaction was initiated by melting of the fluoride salt and that it was fast and complete. While reactive sintering of lithium beryllium fluoride with tricalcium phosphate led to a rather porous product, melting of the reactants with subsequent solidification readily produced a substituted fluorapatite with a near-theoretical bulk density

  12. Synthesis and characterization of novel substituted N-benzothiazole-2-yl-acetamides

    Directory of Open Access Journals (Sweden)

    H.C. Sakarya

    2016-11-01

    Full Text Available Schiff base derivatives of benzothiazole 2a–e have been synthesized by reacting with substituted 2-aminobenzothiazole 1a–e and different substituted benzaldehydes 5a–e. The obtained Schiff bases reaction with NaBH4 has afforded the corresponding some novel amines 3a–e. The condensation of amines with chloroacetylchloride leads to novel amide derivatives 4a–e. The structures of the synthesized compounds are characterized by elemental analysis, IR, MS, 1H NMR and 13C NMR.

  13. Calculation of the total electron excitation cross section in the Born approximation using Slater wave functions for the Li (2s yields 2p), Li (2s yields 3p), Na (3s yields 4p), Mg (3p yields 4s), Ca (4s yields 4p) and K (4s yields 4p) excitations. M.S. Thesis

    Science.gov (United States)

    Simsic, P. L.

    1974-01-01

    Excitation of neutral atoms by inelastic scattering of incident electrons in gaseous nebulae were investigated using Slater Wave functions to describe the initial and final states of the atom. Total cross sections using the Born Approximation are calculated for: Li(2s yields 2p), Na(3s yields 4p), k(4s yields 4p). The intensity of emitted radiation from gaseous nebulae is also calculated, and Maxwell distribution is employed to average the kinetic energy of electrons.

  14. Synergetic Fe substitution and carbon connection in LiMn{sub 1−x}Fe{sub x}PO{sub 4}/C cathode materials for enhanced electrochemical performances

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Su-Yuan; Wang, Cheng-Yang [Key Laboratory for Green Chemical Technology of Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); Collaborative Innovation Center of Chemical Science and Engineer (Tianjin), Tianjin University, Tianjin 300072 (China); Gu, Rong-Min [Department of Chemistry, Tianjin University, Tianjin 300072 (China); Collaborative Innovation Center of Chemical Science and Engineer (Tianjin), Tianjin University, Tianjin 300072 (China); Sun, Shuai [Key Laboratory for Green Chemical Technology of Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); Collaborative Innovation Center of Chemical Science and Engineer (Tianjin), Tianjin University, Tianjin 300072 (China); Li, Ming-Wei, E-mail: mingweili@tju.edu.cn [Department of Chemistry, Tianjin University, Tianjin 300072 (China); Collaborative Innovation Center of Chemical Science and Engineer (Tianjin), Tianjin University, Tianjin 300072 (China)

    2015-04-15

    Highlights: • LiMn{sub 0.6}Fe{sub 0.4}PO{sub 4}/C cathode material shows enhanced rate capability. • The Fe doped in the partial Mn sites could significantly facilitate the Li ions transfer. • The enhanced Li{sup +} ions diffusion contributes to the optimized rate capability of LiMn{sub 0.6}Fe{sub 0.4}PO{sub 4}. • ACM carbonization forms well carbon coating and a 3D carbon network structure. - Abstract: To enhance the rate and cyclic performances of LiMnPO{sub 4} cathode material for lithium-ion batteries, Mn is partially substituted with Fe, and LiMn{sub 1−x}Fe{sub x}PO{sub 4} (x = 0.2, 0.3, 0.4, 0.5) solid solutions are synthesized and investigated. Amphiphilic carbonaceous material (ACM) forms well carbon coating and connects the LiMn{sub 1−x}Fe{sub x}PO{sub 4} crystallites by a three-dimensional (3D) carbon network. The synergetic Fe substitution and carbon connection obviously improve the samples’ rate capacities and cyclic stability. The optimized LiMn{sub 0.6}Fe{sub 0.4}PO{sub 4}/C sample delivers discharge capacities of 160 mA h g{sup −1} at 0.05 C, 148 mA h g{sup −1} at 1 C, and 115 mA h g{sup −1} at 20 C. All samples have well capacity retention (>92%) after 50 charge/discharge cycles at 1 C. The enhanced electrochemical properties are mainly attributed to the improvement of Li ion and electron transport in the LiMn{sub 1−x}Fe{sub x}PO{sub 4}/C samples, respectively mainly resulting from their modified crystal structures caused by Fe substitution and the 3D carbon coating/connection originating from ACM carbonization. LiMn{sub 1−x}Fe{sub x}PO{sub 4} materials exhibit two discharge plateaus at ∼4.0 and ∼3.5 V (vs. Li{sup +}/Li), whose heights respectively reflect the redox potentials of Mn{sup 3+}/Mn{sup 2+} and Fe{sup 3+}/Fe{sup 2+} couples. The plateaus’ lengths correspond to the Mn/Fe ratio in LiMn{sub 1−x}Fe{sub x}PO{sub 4} and are affected by the kinetic behavior of samples. Though the ∼4.0 V plateau shrinks with

  15. Generation time, life history and the substitution rate of neutral mutations.

    Science.gov (United States)

    Lehtonen, Jussi; Lanfear, Robert

    2014-11-01

    Our understanding of molecular evolution is hampered by a lack of quantitative predictions about how life-history (LH) traits should correlate with substitution rates. Comparative studies have shown that neutral substitution rates vary substantially between species, and evidence shows that much of this diversity is associated with variation in LH traits. However, while these studies often agree, some unexplained and contradictory results have emerged. Explaining these results is difficult without a clear theoretical understanding of the problem. In this study, we derive predictions for the relationships between LH traits and substitution rates in iteroparous species by using demographic theory to relate commonly measured life-history traits to genetic generation time, and by implication to neutral substitution rates. This provides some surprisingly simple explanations for otherwise confusing patterns, such as the association between fecundity and substitution rates. The same framework can be applied to more complex life histories if full life-tables are available. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  16. Approaches in Substitution of Organic Solvents

    DEFF Research Database (Denmark)

    Jacobsen, Thomas

    2000-01-01

    In substitution of harmful chemicals or products with less harmful or harmless ones, there are different approaches according to the different situations, the technical requirements to the substitutes, and the goals for the substitution. Three different cases are presented. The substitution process...

  17. Synthesis and pharmacological investigation of 2-(4-dimethylaminophenyl)-3,5-disubstituted thiazolidin-4-ones as anticonvulsants.

    Science.gov (United States)

    Senthilraja, Manavalan; Alagarsamy, Veerachamy

    2012-10-01

    A new series of 2-(4-dimethylaminophenyl)-3-substituted thiazolidin-4-one-5-yl-acetyl acetamides/benzamides were synthesized by the nucleophilic substitution of 3-substituted-2-(4-dimethylaminophenyl)-thiazolidin-4-one-5-yl-acetylchloride with acetamide and benzamide. The starting material 3-substituted-2-(4-dimethylaminophenyl)-thiazolidin-4-one-5-yl-acetylchloride was synthesized from 3-substituted-2-(4-dimethylaminophenyl)-thiazolidin-4-one-5-yl-acetic acid, which in turn was prepared by one-pot reaction of amino component, p-dimethylamino benzaldehyde and mercapto succinic acid. The title compounds were investigated for their anticonvulsant activities; among the test compounds, compound 2-(4-dimethylaminophenyl)-3-phenylamino-thiazolidine-4-one-5-yl-acetylbenzamide (14) emerged as the most active compound of the series and as moderately more potent than the reference standard diazepam. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Amnion s and radio-sterilized porcine skin use as potential matrices for the development of human skin substitutes

    International Nuclear Information System (INIS)

    Martinez P, M. E.; Reyes F, M. L.; Reboyo B, D.; Velasquillo M, M. C.; Sanchez S, R.; Brena M, A. M.; Ibarra P, J. C.

    2014-10-01

    The injuries by burns constitute a primordial problem of public health; they cause a high mortality index, severe physical and psychological disability, etc. The autologous skin transplant is the replacement therapy recommended for its treatment, but in patients that present a high percentage of burnt skin; this is not possible to carry out. Another strategy is the transplant of donated skin; however, due to the little donation that exists in our country is not very feasible to apply this treatment. A challenge of the tissues engineering is to develop biological skin substitutes, based on cells and amnion s, favoring the cutaneous regeneration and quick repair of injuries, diminishing this way the hospitalization expenses. At present skin substitutes that can equal to the same skin do not exist. On the other hand, the mesenchymal stromal cells (Msc) represent an alternative to achieve this objective; since has been demonstrated that the Msc participate in the tissue repair by means of inhibition of pro-inflammatory cytokines and differentiation to dermal fibroblasts and keratinocytes. To apply the Msc in cutaneous injuries a support material is required that to allow transplanting these cells to a lesion or burn. The radio-sterilized human amnion and the radio-sterilized porcine skin, processed by the Radio-Sterilized Tissues Bank of the Instituto Nacional de Investigaciones Nucleares (ININ), are biomaterials that are used as temporary cutaneous coverings. We suppose that these two matrices will be appropriate for the growth and maintenance in cultivation of the Msc, to generate two biological skin substitutes, in collaboration with the Biotechnology Laboratory of the Instituto Nacional de Rehabilitacion. (Author)

  19. Studies on physicochemical properties of pure and iron substituted chromium niobates, Cr{sub 1−x}Fe{sub x}NbO{sub 4} (x = 0, 0.2, 0.4, 0.6)

    Energy Technology Data Exchange (ETDEWEB)

    Sree Rama Murthy, A.; Gnanasekar, K.I. [Materials Chemistry and Metal Fuel Cycle Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India); Govindaraj, R. [Materials Science Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India); Jayaraman, V., E-mail: vjram@igcar.gov.in [Materials Chemistry and Metal Fuel Cycle Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India); Umarji, A.M. [Materials Research Centre, Indian Institute of Science, Bangalore 560012 (India)

    2017-03-15

    Highlights: • Systematic increase in unit cell volume on iron substitution. • Similar mechanism of electronic conduction in these compositions. • Decrease in quadrupole splitting with increasing iron content in Mössbauer spectra. • Iron and chromium exhibited multiple valences, as identified from X-ray photoelectron spectra. - Abstract: Pristine and iron substituted chromium niobates (Cr{sub 1−x}Fe{sub x}NbO{sub 4} with x = 0, 0.2, 0.4 and 0.6) are prepared by solid-state synthesis and phase characterised by X-ray diffraction. Microstructure is determined using scanning electron microscope and micro-chemical analysis is performed by energy dispersive X-ray analysis (EDX). The current-voltage characteristics are studied in the temperature range of 423–723 K. The electrical conductivity of sintered pellets is measured by impedance spectroscopy. Temperature dependent magnetization studies are performed using vibrating sample magnetometer (VSM) and room temperature Bohr magneton number is calculated from the magnetic susceptibility data. The conductivity is passed through a minimum at x = 0.2 in Cr{sub 1−x}Fe{sub x}NbO{sub 4} for x = 0–0.6. X-ray photoelectron spectroscopic studies revealed the surface non-stoichiometry in these compositions.

  20. Registration of DGE-3, a durum wheat disomic substitution line 1E(1B) involving a wheatgrass chromosome

    Science.gov (United States)

    Durum wheat (Triticum turgidum L., 2n = 4x = 28; AABB genomes) alien disomic substitution 1E(1B) line DGE-3 (PI 665473) was developed by the U.S. Department of Agriculture – Agricultural Research Service, Northern Crop Science Lab, Cereal Crops Research Unit, Fargo, ND and released in 2012. It was ...

  1. N4H9Cu7S4: a hydrazinium-based salt with a layered Cu7S4- framework.

    Science.gov (United States)

    Mitzi, David B

    2007-02-05

    Crystals of a hydrazinium-based copper(I) sulfide salt, N4H9Cu7S4 (1), have been isolated by an ambient temperature solution-based process. In contrast to previously reported hydrazinium salts of main-group metal chalcogenides, which consist of isolated metal chalcogenide anions, and ACu7S4 (A = NH4+, Rb+, Tl+, K+), which contains a more three-dimensional Cu7S4- framework with partial Cu-site occupancy, the structure of 1 [P21, a = 6.8621(4) A, b = 7.9851(4) A, c = 10.0983(5) A, beta = 99.360(1) degrees , Z = 2] is composed of extended two-dimensional Cu7S4- slabs with full Cu-site occupancy. The Cu7S4- slabs are separated by a mixture of hydrazinium and hydrazine moieties. Thermal decomposition of 1 into copper(I) sulfide proceeds at a significantly lower temperature than that observed for analogous hydrazinium salts of previously considered metal chalcogenides, completing the transition at temperatures as low as 120 degrees C. Solutions of 1 may be used in the solution deposition of a range of Cu-containing chalcogenide films.

  2. Tungsten phosphanylarylthiolato complexes [W{PhP(2-SC6H4)2-kappa3S,S',P} 2] and [W{P(2-SC6H4)3-kappa4S,S',S",P}2]: synthesis, structures and redox chemistry.

    Science.gov (United States)

    Hildebrand, Alexandra; Lönnecke, Peter; Silaghi-Dumitrescu, Luminita; Hey-Hawkins, Evamarie

    2008-09-14

    PhP(2-SHC6H4)2 (PS2H2) reacts with WCl6 with reduction of tungsten to give the air-sensitive tungsten(IV) complex [W{PhP(2-SC6H4)2-kappa(3)S,S',P}2] (1). 1 is oxidised in air to [WO{PhPO(2-SC6H4)2-kappa(3)S,S',O}{PhP(2-SC6H4)2-kappa(3)S,S',P}] (2). The attempted synthesis of 2 by reaction of 1 with iodosobenzene as oxidising agent was unsuccessful. [W{P(2-SC6H4)3-kappa(4)S,S',S",P}2] (3) was formed in the reaction of P(2-SHC6H4)3 (PS3H3) with WCl6. The W(VI) complex 3 contains two PS3(3-) ligands, each coordinated in a tetradentate fashion resulting in a tungsten coordination number of eight. The reaction of 3 with AgBF4 yields the dinuclear tungsten complex [W2{P(2-SC6H4)3-kappa(4)S,S',S",P}3]BF4 (4). Complexes 1-4 were characterised by spectral methods and X-ray structure determination.

  3. Genotoxicity risk assessment of diversely substituted quinolines using the SOS chromotest.

    Science.gov (United States)

    Duran, Leidy Tatiana Díaz; Rincón, Nathalia Olivar; Galvis, Carlos Eduardo Puerto; Kouznetsov, Vladimir V; Lorenzo, Jorge Luis Fuentes

    2015-03-01

    Quinolines are aromatic nitrogen compounds with wide therapeutic potential to treat parasitic and microbial diseases. In this study, the genotoxicity of quinoline, 4-methylquinoline, 4-nitroquinoline-1-oxide (4-NQO), and diversely functionalized quinoline derivatives and the influence of the substituents (functional groups and/or atoms) on their genotoxicity were tested using the SOS chromotest. Quinoline derivatives that induce genotoxicity by the formation of an enamine epoxide structure did not induce the SOS response in Escherichia coli PQ37 cells, with the exception of 4-methylquinoline that was weakly genotoxic. The chemical nature of the substitution (C-5 to C-8: hydroxyl, nitro, methyl, isopropyl, chlorine, fluorine, and iodine atoms; C-2: phenyl and 3,4-methylenedioxyphenyl rings) of quinoline skeleton did not significantly modify compound genotoxicities; however, C-2 substitution with α-, β-, or γ-pyridinyl groups removed 4-methylquinoline genotoxicity. On the other hand, 4-NQO derivatives whose genotoxic mechanism involves reduction of the C-4 nitro group were strong inducers of the SOS response. Methyl and nitrophenyl substituents at C-2 of 4-NQO core affected the genotoxic potency of this molecule. The relevance of these results is discussed in relation to the potential use of the substituted quinolines. The work showed the sensitivity of SOS chromotest for studying structure-genotoxicity relationships and bioassay-guided quinoline synthesis. © 2013 Wiley Periodicals, Inc.

  4. Substitution effect of Sr2+ by Ca2+ on structure and superconducting properties of Bi2Sr1.6La0.4CuO6+δ (Bi-2201) ceramics

    Science.gov (United States)

    Boudjaoui, S.; Amira, A.; Mahamdioua, N.; Altintas, S.; varilci, A.; Terzioglu, C.

    2018-02-01

    In this work, the effect of Ca2+ iso-valence substitution for Sr2+ on properties of Bi2Sr1.6La0.4CuO6+δ superconductors is presented. Samples series with nominal composition of Bi2Sr1.6-xCaxLa0.4CuO6+δ (x= 0, 0.2, 0.4, 0.6 and 0.8) are prepared by a solid-state reaction method. When Ca content is increased, the X-ray diffraction technique shows that the cell parameters a and c decrease, while b one is almost constant. The scanning electron microscopy analysis reveals that the substitution has no significant effect on the porosity and the grain size of the samples. The physical properties of the samples are studied by the analysis of the magneto-resistivity curves measured under magnetic fields in the range 0-1 T. As Ca is added, the results show that the high temperature transition appears and is pushed up to 94.87 K for x=0.8. The substitution also improves the bulk onset critical transition temperature, the transition width, the residual resistivity, the activation energy of vortices and the irreversibility field. The best results are seen for x=0.4 of Ca content.

  5. Further studies of the thermal and photochemical diels-alder reactions of N-methyl-1,2,4-triazoline-3,5-dione (MeTAD) with naphthalene and some substituted naphthalenes

    Science.gov (United States)

    Breton; Newton

    2000-05-19

    MeTAD thermally reacted with naphthalene (2) and methylated naphthalenes to give equilibrium mixtures of starting materials and [4 + 2] cycloadducts. Methyl substitution on the naphthalene ring generally increased both the amount of cycloadduct formed and the rate of cycloaddition relative to 2. The isolated cycloadducts were all thermally labile and quantitatively reverted to the parent naphthalene in the presence of 2,3-dimethyl-2-butene as a trap for liberated MeTAD. The rates of the cycloreversion reactions were affected by substitution patterns but not appreciably by solvent. A mechanism for the cycloaddition reaction is presented that proposes the involvement of a charge-transfer complex. Photochemically, MeTAD demonstrated lower regioselectivity in its reactions with substituted naphthalenes relative to the corresponding thermal reactions.

  6. Structure and magnetic properties of Zr–Mn substituted strontium ...

    Indian Academy of Sciences (India)

    2Department of Materials Engineering, Najafabad Branch, Islamic Azad ... ions prefer to occupy both 4f1 and 2b however, at higher level of substitution, they prefer exclusively 4f1 site. ... Up to authors' knowledge, the effect of Zr–Mn substitu-.

  7. Medicineringsfejl ved generisk substitution

    DEFF Research Database (Denmark)

    Rölfing, Jan

    2012-01-01

    Generic substitution is a major cause of medical mistakes in the general population. Danish legislation obligates pharmacies to substitute prescribed medicine with the cheapest equivalent formulation, despite variations in product name, packaging, shape and colour. Consequently, medical mistakes...... occur. Scientific evidence on the consequences of generic substitution is sparse. Call upon fellow health workers to report medical mistakes to the national entities and scientific peers, in order to increase awareness and scientific evidence about the problem....

  8. N-(4-Chloro-2-nitrophenylmethanesulfonamide

    Directory of Open Access Journals (Sweden)

    Muhammad Nadeem Arshad

    2008-10-01

    Full Text Available The title compound, C7H7ClN2O4S, is of interest as a precursor to biologically active substituted quinolines. Its structure resembles those of the previously reported N-phenylmethane sulfonamide and its 4-nitro, 4-fluoro and 4-bromo derivatives, with slightly different geometric parameters. An intramolecular N—H...O hydrogen bond gives rise to a six-membered ring. Intermolecular C—H...O contacts stabilize the crystal packing.

  9. Sucrose substitutes affect the cariogenic potential of Streptococcus mutans biofilms.

    Science.gov (United States)

    Durso, S C; Vieira, L M; Cruz, J N S; Azevedo, C S; Rodrigues, P H; Simionato, M R L

    2014-01-01

    Streptococcus mutans is considered the primary etiologic agent of dental caries and contributes significantly to the virulence of dental plaque, especially in the presence of sucrose. To avoid the role of sucrose on the virulence factors of S. mutans, sugar substitutes are commonly consumed because they lead to lower or no production of acids and interfere with biofilm formation. This study aimed to investigate the contribution of sugar substitutes in the cariogenic potential of S. mutans biofilms. Thus, in the presence of sucrose, glucose, sucralose and sorbitol, the biofilm mass was quantified up to 96 h, the pH of the spent culture media was measured, the expression of biofilm-related genes was determined, and demineralization challenge experiments were conduct in enamel fragments. The presence of sugars or sugar substitutes profoundly affected the expression of spaP, gtfB, gtfC, gbpB, ftf, vicR and vicX in either biofilm or planktonic cells. The substitution of sucrose induced a down-regulation of most genes involved in sucrose-dependent colonization in biofilm cells. When the ratio between the expression of biofilm and planktonic cells was considered, most of those genes were down-regulated in biofilm cells in the presence of sugars and up-regulated in the presence of sugar substitutes. However, sucralose but not sorbitol fulfilled the purpose of reducing the cariogenic potential of the diet since it induced the biofilm formation with the lowest biomass, did not change the pH of the medium and led to the lowest lesion depth in the cariogenic challenge.

  10. Structural characterization of Mg substituted on A/B sites in NiFe_2O_4 nanoparticles using autocombustion method

    Science.gov (United States)

    De, Manojit; Tewari, H. S.

    2017-07-01

    In the present paper, we are reporting the synthesis of pure nickel and magnesium ferrite [NiFe_2O_4, MgFe_2O_4] and magnesium-substituted nickel ferrite (Ni_{1-x}Mg_{x/y}Fe_{2-y}O_4; x=y=0.60) on A/B sites with particles size in nanometer range using autocombustion technique. In this study, it has been observed that with increase in sintering temperature, the estimated bulk density of the materials increases. The XRD patterns of the samples show the formation of single-phase materials and the lattice parameters are estimated from XRD patterns. From Raman spectra, the Raman shift of pure NiFe_2O_4 and MgFe_2O_4 are comparable with the experimental values reported in literature. The Raman spectra give five Raman active modes (A_{{1g}} + Eg + 3F_{2g}) which are expected in the spinel structure.

  11. Minimising pain in farm animals: the 3S approach - 'Suppress, Substitute, Soothe'.

    Science.gov (United States)

    Guatteo, R; Levionnois, O; Fournier, D; Guémené, D; Latouche, K; Leterrier, C; Mormède, P; Prunier, A; Servière, J; Terlouw, C; Le Neindre, P

    2012-08-01

    Recently, the French National Institute for Agricultural Research appointed an expert committee to review the issue of pain in food-producing farm animals. To minimise pain, the authors developed a '3S' approach accounting for 'Suppress, Substitute and Soothe' by analogy with the '3Rs' approach of 'Reduction, Refinement and Replacement' applied in the context of animal experimentation. Thus, when addressing the matter of pain, the following steps and solutions could be assessed, in the light of their feasibility (technical constraints, logistics and regulations), acceptability (societal and financial aspects) and availability. The first solution is to suppress any source of pain that brings no obvious advantage to the animals or the producers, as well as sources of pain for which potential benefits are largely exceeded by the negative effects. For instance, tail docking of cattle has recently been eliminated. Genetic selection on the basis of resistance criteria (as e.g. for lameness in cattle and poultry) or reduction of undesirable traits (e.g. boar taint in pigs) may also reduce painful conditions or procedures. The second solution is to substitute a technique causing pain by another less-painful method. For example, if dehorning cattle is unavoidable, it is preferable to perform it at a very young age, cauterising the horn bud. Animal management and constraint systems should be designed to reduce the risk for injury and bruising. Lastly, in situations where pain is known to be present, because of animal management procedures such as dehorning or castration, or because of pathology, for example lameness, systemic or local pharmacological treatments should be used to soothe pain. These treatments should take into account the duration of pain, which, in the case of some management procedures or diseases, may persist for longer periods. The administration of pain medication may require the intervention of veterinarians, but exemptions exist where breeders are

  12. Structural, morphological and magnetic properties variation of nickel-manganese ferrites with lithium substitution

    Energy Technology Data Exchange (ETDEWEB)

    Momin, A.A., E-mail: abdulla.al.momin@gmail.com; Parvin, Roksana; Akther Hossain, A.K.M.

    2017-02-01

    Mixed ferrites with nominal chemical compositions Li{sub x}Ni{sub 0.2}Mn{sub 0.8−2x}Fe{sub 2+x}O{sub 4} ranging from x=0 to 0.4 in the steps of 0.1 have been prepared by the auto combustion technique. The X-ray diffraction patterns consist of major cubic spinel Li{sub x}Ni{sub 0.2}Mn{sub 0.8−2x}Fe{sub 2+x}O{sub 4} phase with minor impurity phases (Fe{sub 2}O{sub 3} and MnO) and with Li substitution phase purity has increased, such that for x=0.4 pure phase spinel structure has been obtained. The lattice parameter has decreased with the increase in Li content obeying Vegard’s law. Both the bulk density and theoretical density have decreased with Li content and with sintering temperature (T{sub s}) up to 1300 °C ρ{sub B} has increased and beyond that it has decreased. Morphological studies have performed by a high resolution optical microscope and observed that average grain size noticeably dependent on Li substitution. The initial permeability (μ{sub i}′′) has found to decrease with Li substitution. The Curie temperature (T{sub C}) has determined from the temperature dependent μ{sub i}′′ and found to increases with Li content. From the room temperature magnetization measurement, it has observed that all samples are in ferrimagnetic state at room temperature. The number of Bohr magneton has been obtained from the observed saturation magnetization. Dielectric constant, dielectric loss tangent, ac conductivity and complex impedance are studied in the frequency range 20 Hz–10 MHz. Frequency dependence of dielectric constant in lower frequencies indicates a usual dielectric dispersion due to the Maxwell-Wagner type interfacial polarization. Dielectric loss tangent shows similar behavior like dielectric constant. The complex impedance analysis has been used to study the effect of grain and grain boundary on the electrical properties and with Li content both grain and grain boundary resistance show an increasing trend. The ac conductivity shows

  13. Synthesis of substituted tetrahydroisoquinolines by lithiation then electrophilic quench.

    Science.gov (United States)

    Talk, Ruaa A; Duperray, Alexia; Li, Xiabing; Coldham, Iain

    2016-06-07

    Substituted N-tert-butoxycarbonyl (Boc)-1,2,3,4-tetrahydroisoquinolines were prepared and treated with n-butyllithium in THF at -50 °C to test the scope of the metallation and electrophilic quench. The lithiation was optimised by using in situ ReactIR spectroscopy and the rate of rotation of the carbamate was determined. The 1-lithiated intermediates could be trapped with a variety of electrophiles to give good yields of 1-substituted tetrahydroisoquinoline products. Treatment with acid or reduction with LiAlH4 allows conversion to the N-H or N-Me compound. The chemistry was applied to the efficient total syntheses of the alkaloids (±)-crispine A and (±)-dysoxyline.

  14. Synthesis, Structure and Properties of Various Molecules Based on the 4,8,12-trioxa-4,8,12,12c-tetrahydrodibenzo[cd,mn]pyrene System With an Evaluation of the Effect Differing Molecular Substitution Patterns Has on the Space Group Symmetry

    DEFF Research Database (Denmark)

    Faldt, André; Krebs, Frederik C; Thorup, Niels

    1997-01-01

    of opposite chirality are present within the unit cell, Finally compound 13 crystallises in a centrosymmetric space group. The room temperature pyroelectric coefficient of 3 has been determined, The spatial extent of the trioxatriangulene ground system has been perturbed by chemical substitution......4,8,12-Trioxa-4,8,12,12c-tetrahydrodibenzo [cd,mn]pyrene (3),2,6,10-tri-tert-butyl-4,8,12 -trioxa-4,8,12,12c-tetrahydrodibenzo [cd,mn]pyrene (11) and 2,6,10-tri-tert-butyl-4,8,12-trioxa-12c -methyl-4,8,12,12c -tetrahydrodibenzo[cd,mn]pyrene (12)have been synthesised and their crystal structures...... and the effect: of the substitutions upon the space group symmetry of the chemical derivative has been uncovered by X-ray structural resolution, The non-centrosymmetric point group symmetry of the molecules is reflected in a non-centrosymmetric space group symmetry whenever the spatial perturbations do...

  15. Hydrogen-assisted post-growth substitution of tellurium into molybdenum disulfide monolayers with tunable compositions

    Science.gov (United States)

    Yin, Guoli; Zhu, Dancheng; Lv, Danhui; Hashemi, Arsalan; Fei, Zhen; Lin, Fang; Krasheninnikov, Arkady V.; Zhang, Ze; Komsa, Hannu-Pekka; Jin, Chuanhong

    2018-04-01

    Herein we report the successful doping of tellurium (Te) into molybdenum disulfide (MoS2) monolayers to form MoS2x Te2(1-x) alloy with variable compositions via a hydrogen-assisted post-growth chemical vapor deposition process. It is confirmed that H2 plays an indispensable role in the Te substitution into as-grown MoS2 monolayers. Atomic-resolution transmission electron microscopy allows us to determine the lattice sites and the concentration of introduced Te atoms. At a relatively low concentration, tellurium is only substituted in the sulfur sublattice to form monolayer MoS2(1-x)Te2x alloy, while with increasing Te concentration (up to ˜27.6% achieved in this study), local regions with enriched tellurium, large structural distortions, and obvious sulfur deficiency are observed. Statistical analysis of the Te distribution indicates the random substitution. Density functional theory calculations are used to investigate the stability of the alloy structures and their electronic properties. Comparison with experimental results indicate that the samples are unstrained and the Te atoms are predominantly substituted in the top S sublattice. Importantly, such ultimately thin Janus structure of MoS2(1-x)Te2x exhibits properties that are distinct from their constituents. We believe our results will inspire further exploration of the versatile properties of asymmetric 2D TMD alloys.

  16. The Role of BRCA1 in Suppressing Epithelial Mesenchymal Transition in Mammary Gland and Tumor Development

    Science.gov (United States)

    2016-11-01

    Berton D, Nicholls M, Srinivasan D, Raman R, Girshik S, Kigonya P, Alonso S, Sanbhadti R, Barletta S, Pot D, Sheth M, Demchok JA, Mills Shaw KR, Yang L...443:421–426. 8. Krishnamurthy J, Ramsey MR, Ligon KL, Torrice C, Koh A, Bonner-Weir S, Sharpless NE. p16INK4a induces an age-dependent decline in

  17. Cation-substituted spinel oxide and oxyfluoride cathodes for lithium ion batteries

    Science.gov (United States)

    Manthiram, Arumugam; Choi, Wonchang

    2010-05-18

    The present invention includes compositions and methods of making cation-substituted and fluorine-substituted spinel cathode compositions by firing a LiMn2-y-zLiyMzO4 oxide with NH4HF2 at low temperatures of between about 300 and 700.degree. C. for 2 to 8 hours and a .eta. of more than 0 and less than about 0.50, mixed two-phase compositions consisting of a spinel cathode and a layered oxide cathode, and coupling them with unmodified or surface modified graphite anodes in lithium ion cells.

  18. The [4Fe-4S](2+) cluster in reconstituted biotin synthase binds S-adenosyl-L-methionine.

    Science.gov (United States)

    Cosper, Michele Mader; Jameson, Guy N L; Davydov, Roman; Eidsness, Marly K; Hoffman, Brian M; Huynh, Boi Hanh; Johnson, Michael K

    2002-11-27

    The combination of resonance Raman, electron paramagnetic resonance and Mössbauer spectroscopies has been used to investigate the effect of S-adenosyl-l-methionine (SAM) on the spectroscopic properties of the [4Fe-4S]2+ cluster in biotin synthase. The results indicate that SAM interacts directly at a unique iron site of the [4Fe-4S]2+ cluster in BioB and support the hypothesis of a common inner-sphere mechanism for the reductive cleavage of SAM in the radical SAM family of Fe-S enzymes.

  19. Chemical synthesis and stabilization of magnesium substituted brushite

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Donghyun [Department of Biomedical Engineering, Chung-Ang University, 221 Heukseok-Dong, Dongjak-Gu, Seoul 156-756 (Korea, Republic of); Kumta, Prashant N., E-mail: pkumta@pitt.edu [Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15260 (United States); Department of Mechanical Engineering and Materials Sceince, University of Pittsburgh, Pittsburgh, PA 15260 (United States); Department of Chemical and Petroleum Engineering, University of Pittsburgh, Pittsburgh, PA 15260 (United States)

    2010-08-30

    Hydroxyapatite (Ca{sub 10}(PO{sub 4}){sub 6}(OH){sub 2}) is the most ubiquitous calcium phosphate phase used in implant coatings and more recently in gene/drug delivery applications due to its chemical stability under normal physiological conditions (37 deg. C, pH {approx} 7.5, 1 atm.). However, different calcium phosphate phases, such as brushite (CaH(PO{sub 4}){center_dot}2(H{sub 2}O)) and tricalcium phosphate (Ca{sub 3}(PO{sub 4}){sub 2}) which are thermodynamically unstable under physiological conditions are also being explored for biomedical applications. One way of stabilizing these phases under physiological conditions is to introduce magnesium to substitute for calcium in the brushite lattice. The role of magnesium as a stabilizing agent for synthesizing brushite under physiological conditions at room temperature has been studied. Chemical analysis, Fourier transform infrared spectroscopy and X-ray diffraction have also been conducted to validate the formation of magnesium substituted brushite under physiological conditions.

  20. Influence of sintering temperature on structural, dielectric and magnetic properties of Li substituted CuFe{sub 2}O{sub 4} nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Manikandan, V. [Department of Physics, Government College of Technology, Coimbatore, Tamil Nadu-13 (India); Vanitha, A., E-mail: avanitha570@gmail.com [Department of Physics, Government College of Technology, Coimbatore, Tamil Nadu-13 (India); Kumar, E. Ranjith, E-mail: ranjueaswar@gmail.com [Department of Physics, Dr. NGP Institute of Technology, Coimbatore, Tamil Nadu-48 (India); Kavita, S. [Centre for Automotive Energy Materials, International Advanced Research Centre for Powder Metallurgy and New Materials, Chennai, Tamil nadu-113 (India)

    2017-03-15

    Lithium substituted copper ferrite (Li{sub x}Cu{sub (1−x)}Fe{sub 2}O{sub 4}) nanoparticles have been successfully synthesized by chemical co-precipitation method. XRD analysis confirms the formation of Li substituted Cu ferrite with crystallite size in the range of 17–41 nm. The SEM and TEM microstructure of nanoparticle is well characterized and fine nature improves while increasing of Li concentration and also FTIR analysis exhibit the usual behaviour of ferrite materials. The dielectric properties of the material are increased with increase of concentration. The hysteresis loop is increased which is evident from the increase of saturation magnetization which implies that soft magnetic material has altered into hard magnetic material - Highlights: • Nano rod formation has been initiated while increase of Li concentration. • Under the strong influence of sintering temperature, the soft magnetic behaviour has been changed into hard magnetic behaviour. • The average crystallite sizes of the samples are in the range of 17-41 nm.

  1. (E-1-(2,4-Dinitrophenyl-2-(3-ethoxy-4-hydroxybenzylidenehydrazine

    Directory of Open Access Journals (Sweden)

    Hoong-Kun Fun

    2014-01-01

    Full Text Available The molecule of the title hydrazine derivative, C15H14N4O6, is essentially planar, the dihedral angle between the substituted benzene rings being 2.25 (9°. The ethoxy and hydroxy groups are almost coplanar with their bound benzene ring [r.m.s. deviation = 0.0153 (2 Å for the ten non-H atoms]. Intramolecular N—H...O and O—H...Oethoxy hydrogen bonds generate S(6 and S(5 ring motifs, respectively. In the crystal, molecules are linked by O—H...Onitro hydrogen bonds into chains propagating in [010]. Weak aromatic π–π interactions, with centroid–centroid distances of 3.8192 (19 and 4.0491 (19 Å, are also observed.

  2. Clinical Applications of S53P4 Bioactive Glass in Bone Healing and Osteomyelitic Treatment: A Literature Review

    Directory of Open Access Journals (Sweden)

    N. A. P. van Gestel

    2015-01-01

    Full Text Available Nowadays, S53P4 bioactive glass is indicated as a bone graft substitute in various clinical applications. This review provides an overview of the current published clinical results on indications such as craniofacial procedures, grafting of benign bone tumour defects, instrumental spondylodesis, and the treatment of osteomyelitis. Given the reported results that are based on examinations, such as clinical examinations by the surgeons, radiographs, CT, and MRI images, S53P4 bioactive glass may be beneficial in the various reported applications. Especially in craniofacial reconstructions like mastoid obliteration and orbital floor reconstructions, in grafting bone tumour defects, and in the treatment of osteomyelitis very promising results are obtained. Randomized clinical trials need to be performed in order to determine whether bioactive glass would be able to replace the current golden standard of autologous bone usage or with the use of antibiotic containing PMMA beads (in the case of osteomyelitis.

  3. Synthesis, crystal structure, and transport properties of Fe substituted rhombohedral skutterudite derivatives Co4−xFexGe6Se6

    KAUST Repository

    Wei, Kaya

    2014-11-01

    We report on the synthesis and low temperature transport properties of rhombohedral derivatives of the cubic skutterudite CoSb3, namely Co4-xFexGe6Se6 with x = 0, 1, 1.5. Rietveld refinement and elemental analyses were used to identify the structure and stoichiometry of the compositions. The thermal conductivity was investigated by employing the Debye model with different phonon-scattering parameters. This investigation demonstrates that Fe substitution is feasible in these skutterudite derivatives and can significantly affect the transport properties as compared with Co4Ge6Se6. © 2014 Elsevier B.V. All rights reserved.

  4. Synthesis, crystal structure, and transport properties of Fe substituted rhombohedral skutterudite derivatives Co4−xFexGe6Se6

    KAUST Repository

    Wei, Kaya; Dong, Yongkwan; Puneet, Pooja; Tritt, Terry M.; Nolas, George S.

    2014-01-01

    We report on the synthesis and low temperature transport properties of rhombohedral derivatives of the cubic skutterudite CoSb3, namely Co4-xFexGe6Se6 with x = 0, 1, 1.5. Rietveld refinement and elemental analyses were used to identify the structure and stoichiometry of the compositions. The thermal conductivity was investigated by employing the Debye model with different phonon-scattering parameters. This investigation demonstrates that Fe substitution is feasible in these skutterudite derivatives and can significantly affect the transport properties as compared with Co4Ge6Se6. © 2014 Elsevier B.V. All rights reserved.

  5. Biotransformations of Substituted Phenylethanols and Acetophenones by Environmental Bacteria

    Directory of Open Access Journals (Sweden)

    Edna Kagohara

    2008-01-01

    Full Text Available Whole cells of hydrocarbon-degrading bacteria, isolated from polluted sediments in the Santos Estuary (Baixada Santista, São Paulo, Brazil, were able to catalyse oxidoreduction reactions with various substituted phenylethanols and acetophenones as substrates. A number of substituted phenylethanols were formed with high (>99 % enantiomeric excess. The results of microbial oxidation of phenylethanols 2, 3, 5–7 by Acinetobacter sp. 6.4T and the reduction of acetophenones 1a–6a by Serratia marcescens 5.4T showed that the bacteria used as biocatalysts in this study present significant potential for exploitation in biotechnological processes. The reduction of prochiral acetophenones by Serratia marcescens 3.5T yielded optically active alcohols with 90–99 % enantiomeric excess, and Acinetobacter sp. 6.4T is a potential biocatalyst for the oxidation of alcohols.

  6. Characterization of the Sr(2+)- and Cd(2+)-Substituted Oxygen-Evolving Complex of Photosystem II by Quantum Mechanics/Molecular Mechanics Calculations.

    Science.gov (United States)

    Pitari, Fabio; Bovi, Daniele; Narzi, Daniele; Guidoni, Leonardo

    2015-09-29

    The Mn4CaO5 cluster in the oxygen-evolving complex is the catalytic core of the Photosystem II (PSII) enzyme, responsible for the water splitting reaction in oxygenic photosynthesis. The role of the redox-inactive ion in the cluster has not yet been fully clarified, although several experimental data are available on Ca2+-depleted and Ca2+-substituted PSII complexes, indicating Sr2+-substituted PSII as the only modification that preserves oxygen evolution. In this work, we investigated the structural and electronic properties of the PSII catalytic core with Ca2+ replaced with Sr2+ and Cd2+ in the S2 state of the Kok−Joliot cycle by means of density functional theory and ab initio molecular dynamics based on a quantum mechanics/ molecular mechanics approach. Our calculations do not reveal significant differences between the substituted and wild-type systems in terms of geometries, thermodynamics, and kinetics of two previously identified intermediate states along the S2 to S3 transition, namely, the open cubane S2 A and closed cubane S2 B conformers. Conversely, our calculations show different pKa values for the water molecule bound to the three investigated heterocations. Specifically, for Cd-substituted PSII, the pKa value is 5.3 units smaller than the respective value in wild type Ca-PSII. On the basis of our results, we conclude that, assuming all the cations sharing the same binding site, the induced difference in the acidity of the binding pocket might influence the hydrogen bonding network and the redox levels to prevent the further evolution of the cycle toward the S3 state.

  7. Lutzomyia wellcomei Fraiha, Shaw & Lainson (Diptera, Psychodidae, Phlebotominae em Fragmento de Mata Atlântica do Rio Grande do Norte, Nordeste do Brasil

    Directory of Open Access Journals (Sweden)

    Marcos Paulo Gomes Pinheiro

    2013-12-01

    Resumo. As leishmanioses podem afetar seres humanos e animais nas formas visceral e tegumentar. A forma tegumentar tem sido associada, entre outras espécies, a Lutzomyia wellcomei Fraiha, Shaw & Lainson, inicialmente encontrado na região amazônica. O estudo se baseou em coletas mensais de janeiro a dezembro em um fragmento de Mata Atlântica e em um ambiente peridomiciliar, com armadilhas luminosas CDC. Esse é o primeiro estudo sistematizado sobre essa espécie no Rio Grande do Norte. Os insetos foram identificados e analisados em relação às chuvas no local. Alguns espécimes de L. wellcomei foram metalizados sob fita de carbono, visualizados e fotografados em microscópio eletrônico de varredura. A espécie mais abundante na área de mata foi Lutzomyia walkeri Newstead seguida por L. wellcomei. Do total capturado no ambiente de mata e no peridomicílio, cerca de 8% corresponde a L. wellcomei, sendo esta a espécie predominante no ambiente de mata no período chuvoso. Flebotomíneos L. wellcomei não foram capturados em ambiente peridomiciliar. Na mata essa espécie foi encontrada juntamente às espécies Lutzomyia whitmani Antunes & Coutinho e Lutzomyia intermedia Lutz & Neiva. Machos e fêmeas Lutzomyia longipalpis Lutz & Neiva foram predominantes no ambiente peridomiciliar. A análise microscópica da morfologia externa de L. wellcomei revela detalhes da cabeça de machos e fêmeas.

  8. Thiocyanate ligand substitution kinetics of the solar cell dye Z-907 by 3-methoxypropionitrile and 4-tert-butylpyridine at elevated temperatures

    DEFF Research Database (Denmark)

    Phuong, Nguyen Tuyet; Degn, Rikke; Nguyen, Thai Hoang

    2009-01-01

    )     A similar mechanism describes the heterogeneous substitution reactions of Z-907 attached to the surface of TiO2 particles with 3-MPN and 4-TBP. All the six homogeneous and heterogeneous rate constants were obtained at 100 ºC by monitoring the decay of Z-907 and product formation in test tube experiments...

  9. The formation of [M-H]+ ions in N-alkyl-substituted thieno[3,4-c]-pyrrole-4,6-dione derivatives during atmospheric pressure photoionization mass spectrometry

    KAUST Repository

    Sioud, Salim

    2014-10-09

    RESULTS [M-H]+ ions were observed under APPI conditions. The type of dopant and the length of the alkyl chain affected the formation of these ions. MS/MS fragmentation of [M-H]+ and [M + H]+ ions exhibited completely different patterns. Theoretical calculations revealed that the loss of hydrogen molecules from the [M + H]+ ions is the most favourable condition under which to form [M-H]+ ions.CONCLUSIONS [M-H]+ ions were detected in all the TPD derivatives studied here under the special experimental conditions during APPI, using a halogenated benzene dopant, and TPD containing substituted N-alkyl side chains with a minimum of four carbon atoms. Density functional theory calculations showed that for [M-H]+ ions to be formed under these conditions, the loss of hydrogen molecules from the [M + H]+ ions is proposed to be necessary.RATIONALE The formation of ions during atmospheric pressure photoionization (APPI) mass spectrometry in the positive mode usually provides radical cations and/or protonated species. Intriguingly, during the analysis of some N-alkyl-substituted thieno[3,4-c]pyrrole-4,6-dione (TPD) derivatives synthesized in our laboratory, unusual [M-H]+ ion peaks were observed. In this work we investigate the formation of [M-H]+ ions observed under APPI conditions.METHODS Multiple experimental parameters, including the type of ionization source, the composition of the solvent, the type of dopant, the infusion flow rate, and the length of the alkyl side chain were investigated to determine their effects on the formation of [M-H]+ ions. In addition, a comparison study of the gas-phase tandem mass spectrometric (MS/MS) fragmentation of [M + H]+ vs [M-H]+ ions and computational approaches were used.

  10. N-Substituted 5-Amino-6-methylpyrazine-2,3-dicarbonitriles: Microwave-Assisted Synthesis and Biological Properties

    Directory of Open Access Journals (Sweden)

    Ondrej Jandourek

    2014-01-01

    Full Text Available In this work a series of 15 N-benzylamine substituted 5-amino-6-methyl-pyrazine-2,3-dicarbonitriles was prepared by the aminodehalogenation reactions using microwave assisted synthesis with experimentally set and proven conditions. This approach for the aminodehalogenation reaction was chosen due to its higher yields and shorter reaction times. The products of this reaction were characterized by IR, NMR and other analytical data. The compounds were evaluated for their antibacterial, antifungal and herbicidal activity. Compounds 3 (R = 3,4-Cl, 9 (R = 2-Cl and 11 (R = 4-CF3 showed good antimycobacterial activity against Mycobacterium tuberculosis (MIC = 6.25 µg/mL. It was found that the lipophilicity is important for antimycobacterial activity and the best substitution on the benzyl moiety of the compounds is a halogen or trifluoromethyl group according to Craig’s plot. The activities against bacteria or fungi were insignificant. The presented compounds also inhibited photosynthetic electron transport in spinach chloroplasts and the IC50 values of the active compounds varied in the range from 16.4 to 487.0 µmol/L. The most active substances were 2 (R = 3-CF3, 3 (R = 3,4-Cl and 11 (R = 4-CF3. A linear dependence between lipophilicity and herbicidal activity was observed.

  11. The superconducting gaps of C-substituted and Al-substituted MgB2 single crystals by point-contact spectroscopy

    International Nuclear Information System (INIS)

    Daghero, D.; Gonnelli, R.S.; Ummarino, G.A.; Calzolari, A.; Dellarocca, Valeria; Stepanov, V.A.; Zhigadlo, N.; Kazakov, S.M.; Karpinski, J.

    2005-01-01

    We studied the effects of carbon and aluminum substitutions on the gaps of the two-band superconductor MgB 2 by means of point-contact measurements in Mg(B 1-x C x ) 2 and Mg 1-y Al y B 2 single crystals with 0≤x≤0.132 and 0≤y≤0.21. The gap amplitudes, Δ ω and Δ π , were determined by fitting the conductance curves of the point contacts with the standard Blonder-Tinkham-Klapwijk (BTK) model generalized to the two-band case. Whenever possible, their values were confirmed by the independent fit (with a single-band BTK model) of the partial contribution of the two bands to the conductance, separated by means of a suitable magnetic field B*. In C-substituted crystals, the two gaps remain clearly distinct up to x∝0.10, but at x=0.132 we observed for the first time their merging into a single gap Δ≅3 meV with a gap ratio 2Δ=k B T c close to the standard BCS value. In Al-substituted crystals, we found no evidence of this gap merging. Instead, Δ π reaches the value 0.4 meV at y=0.21, where Δ π saturates at about 4 meV. These results are compared with other recent experimental findings in polycrystals and with the predictions of the models for multiband superconductivity. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  12. Rates of proton transfer to Fe-S-based clusters: comparison of clusters containing {MFe(mu(2)-S)(2)}n+ and {MFe(3)(mu(3)-S)(4)}n+ (M = Fe, Mo, or W) cores.

    Science.gov (United States)

    Bates, Katie; Garrett, Brendan; Henderson, Richard A

    2007-12-24

    The rates of proton transfer from [pyrH]+ (pyr = pyrrolidine) to the binuclear complexes [Fe2S2Cl4]2- and [S2MS2FeCl2]2- (M = Mo or W) are reported. The reactions were studied using stopped-flow spectrophotometry, and the rate constants for proton transfer were determined from analysis of the kinetics of the substitution reactions of these clusters with the nucleophiles Br- or PhS- in the presence of [pyrH]+. In general, Br- is a poor nucleophile for these clusters, and proton transfer occurs before Br- binds, allowing direct measure of the rate of proton transfer from [pyrH]+ to the cluster. In contrast, PhS- is a better nucleophile, and a pathway in which PhS- binds preferentially to the cluster prior to proton transfer from [pyrH]+ usually operates. For the reaction of [Fe2S2Cl4]2- with PhS- in the presence of [pyrH]+ both pathways are observed. Comparison of the results presented in this paper with analogous studies reported earlier on cuboidal Fe-S-based clusters allows discussion of the factors which affect the rates of proton transfer in synthetic clusters including the nuclearity of the cluster core, the metal composition, and the nature of the terminal ligands. The possible relevance of these findings to the protonation sites of natural Fe-S-based clusters, including FeMo-cofactor from nitrogenase, are presented.

  13. Substitution Relationship Between The Agency Problem Control Mechanisms in Malaysia: Simultaneous Equation Analysis

    Directory of Open Access Journals (Sweden)

    D. Agus Harjito

    2009-05-01

    Full Text Available This study investigates the substitution relationship (substitutability between debt policy, insider ownership, and dividend policy as the agency problem control mechanism in Malaysia. If the substitution relationship exists between the agency control mechanisms, the agency problem can be reduced through this relationship. Reducing the agency problem as a result can increase the firm value proxied by Tobin’s Q. This study employs 396 firms sample listed on Malaysian Bourse from 2001 to 2004. To achieves the objectives, this study uses two-stage least square method. The results of this study indicate that the substitutability between debt policy, insider ownership, and dividend policy as agency problem control mechanism does not fully exist in Malaysia. Apparently the substitutability only exists for debt policy and dividend. There is no substitution between debt policy and insider ownership as well as between dividend policy and insider ownership. Key words: debt policy, insider ownership, dividend policy, agency problem, firm value

  14. Carbon-14 kinetic isotope effects and mechanisms of addition of 2,4-dinitrobenzenesulfenyl chloride to substituted styrenes-1-14C and styrenes-2-14C

    International Nuclear Information System (INIS)

    Kanska, M.; Fry, A.

    1983-01-01

    As the first reported examples of carbon isotope effects in simple electrophilic addition reactions we have measured the carbon-14 kinetic isotope effects in the addition of 2,4-dinitrobenzenesulfenyl chloride to a series of para-substituted α and β-labeled styrenes in acetic acid at 30.1 0 C: for para substituents Cl, H, and CH 3 the k/ 14 K values for α labeling are 1.027, 1.022, and 1.004, and the k/ 14 k values for β labeling are 1.035, 1.032, and 1.037, all +/-approx.0.004. The kinetics of the reaction were measured for the p-CH 3 O,p-CH 3 , unsubstituted, p-Cl, and m-NO 2 styrenes; electron-donating groups strongly accelerate the reaction, and electron-withdrawing groups retard it. The Hammett plot is curved with p + values ranging from about -4.6 at the electron-donating group (EDG) end to about -1.8 at the electron-withdrawing group (EWG) end. Both the isotope effect and kinetic data, and related data from the literature, are interpreted in terms of a changing mechanism, with the activated complexes of the rate-determining steps having much open carbenium ion (ion pair) character for EDG-substituted styrenes and much cyclic thiiranium io (ion par) character for EWG-substituted styrenes. 1 figure, 2 tables

  15. Synthesis, DNA binding ability and anticancer activity of 2-heteroaryl substituted benzimidazoles linked pyrrolo[2,1-c][1,4]benzodiazepine conjugates.

    Science.gov (United States)

    Kamal, Ahmed; Pogula, Praveen Kumar; Khan, Mohammed Naseer Ahmed; Seshadri, Bobburi Naga; Sreekanth, Kokkonda

    2013-08-01

    As a continuation of our efforts to develop the benzimidazole-PBD conjugates as potential anticancer agents, a series of heteroaryl substituted benzimidazole linked PBD conjugates has been synthesized and evaluated for their anticancer potential in 60 human cancer cell lines. Most of the compounds exhibited promising anticancer activity and interestingly, compounds 4c and 4d displayed significant activity in most of the cell lines tested. Whereas, compound 4e showed selectivity in renal cancer cells with GI50 values of <10 and 70 nM against RXF 393 and UO-31 cell lines, respectively. Further, these compounds also showed significant DNA-binding affinity by thermal denaturation study using duplex form of calf thymus (CT) DNA.

  16. Media Substitution in Advertising: A Spirited Case Study

    OpenAIRE

    Mark W. Frank

    2006-01-01

    This paper uses an unusually rich sample of liquor brands in the U.S. over the period 1994 to 2004 to test substitutability of advertising media. The liquor industry in the U.S. has experienced a substantial increase in case sales and advertising expenditures since the mid-1990s, raising numerous public policy concerns. Moreover, the mix of advertising media used by liquor brands also changed substantially following the industry’s decision in 1996 to begin using radio and television media. We...

  17. Sample preparation for arsenic speciation analysis in baby food by generation of substituted arsines with atomic absorption spectrometry detection

    Czech Academy of Sciences Publication Activity Database

    Huber, C. S.; Vale, M. G. R.; Dessuy, M. B.; Svoboda, Milan; Musil, Stanislav; Dědina, Jiří

    2017-01-01

    Roč. 175, DEC (2017), s. 406 -412 ISSN 0039-9140 R&D Projects: GA MŠk(CZ) LH15174 Institutional support: RVO:68081715 Keywords : slurry sampling * methyl-substituted arsenic species * hydride generation-cryotrapping-atomic absorption spectrometry Subject RIV: CB - Analytical Chemistry, Separation OBOR OECD: Analytical chemistry Impact factor: 4.162, year: 2016

  18. Sample preparation for arsenic speciation analysis in baby food by generation of substituted arsines with atomic absorption spectrometry detection

    Czech Academy of Sciences Publication Activity Database

    Huber, C. S.; Vale, M. G. R.; Dessuy, M. B.; Svoboda, Milan; Musil, Stanislav; Dědina, Jiří

    2017-01-01

    Roč. 175, DEC (2017), s. 406-412 ISSN 0039-9140 R&D Projects: GA MŠk(CZ) LH15174 Institutional support: RVO:68081715 Keywords : slurry sampling * methyl-substituted arsenic species * hydride generation-cryotrapping-atomic absorption spectrometry Subject RIV: CB - Analytical Chemistry, Separation OBOR OECD: Analytical chemistry Impact factor: 4.162, year: 2016

  19. 40 CFR Appendix D to Subpart G of... - Substitutes Subject to Use Restrictions and Unacceptable Substitutes

    Science.gov (United States)

    2010-07-01

    ... the following criteria, derived from Society of Automotive Engineers (SAE) standards and recommended... Substitutes] Application Substitute Decision Conditions Comments Electronics Cleaning w/CFC-113 and MCF HFC... Sector [Acceptable Subject to Narrowed Use Limits] Application Substitute Decision Comments Electronics...

  20. Substituted N-Benzylpyrazine-2-carboxamides: Synthesis and Biological Evaluation

    Directory of Open Access Journals (Sweden)

    Katarína Kráľová

    2012-11-01

    Full Text Available A series of twelve amides was synthesized via aminolysis of substituted pyrazinecarboxylic acid chlorides with substituted benzylamines. Compounds were characterized with analytical data and assayed in vitro for their antimycobacterial, antifungal, antibacterial and photosynthesis-inhibiting activity. 5-tert-Butyl-6-chloro-N-(4-methoxybenzylpyrazine-2-carboxamide (12 has shown the highest antimycobacterial activity against Mycobacterium tuberculosis (MIC = 6.25 µg/mL, as well as against other mycobacterial strains. The highest antifungal activity against Trichophyton mentagrophytes, the most susceptible fungal strain tested, was found for 5-chloro-N-(3-trifluoromethylbenzyl-pyrazine-2-carboxamide (2, MIC = 15.62 µmol/L. None of the studied compounds exhibited any activity against the tested bacterial strains. Except for 5-tert-butyl-6-chloro-N-benzylpyrazine-2-carboxamide (9, IC50 = 7.4 µmol/L and 5-tert-butyl-6-chloro-N-(4-chlorobenzylpyrazine-2-carboxamide (11, IC50 = 13.4 µmol/L, only moderate or weak photosynthesis-inhibiting activity in spinach chloroplasts (Spinacia oleracea L. was detected.

  1. The 4p-5d, 6d and 4p-6s, 7s transitions of Mo IX

    International Nuclear Information System (INIS)

    Khatoon, S.; Chaghtai, M.S.Z.; Rahimullah, K.

    1979-01-01

    The transitions 4p-5d, 6d and 4p-6s, 7s have been studied for the first time in Mo IX. The authors have identified 42 4p-5d, 36 4p-6d, 22 4p-6s and 22 4p-7s transitions, establishing 16 4p 3 5d, 14 4p 3 6d and all the ten 4p 3 6s, 7s levels of the spectrum concerned. The ionization energy is estimated to be (1 323 700 +- 700)cm -1 or (164.11 +- 0.09)eV. The spectrum was recorded in sliding and open spark discharges with a 5 m grazing incidence spectrograph of Lund University (Sweden) from about 40 A to 440 A. (Auth.)

  2. Curvature and elasticity of substitution: what is the link?

    Czech Academy of Sciences Publication Activity Database

    Matveenko, Andrei; Matveenko, V.

    2014-01-01

    Roč. 10, č. 2 (2014), s. 7-20 ISSN 1800-5845 Grant - others:UK(CZ) GAUK 308214 Institutional support: PRVOUK-P23 Keywords : curvature * elasticity of substitution * production function Subject RIV: AH - Economics

  3. Synthesis of C3/C1-Substituted Tetrahydroisoquinolines

    Directory of Open Access Journals (Sweden)

    Mohamed Mihoubi

    2015-08-01

    Full Text Available A broad biological screening of the natural alkaloid N-methylisosalsoline (2 extracted from Hammada scoparia leaves against a panel of human and parasitic proteases revealed an interesting activity profile of 2 towards human 20S proteasome. This outcome suggests that the 1,2,3,4-tetrahydroisoquinoline skeleton may be exploited as a template for the development of novel anticancer agents. In this article, we report the synthesis and chemical characterization of a new series of isosalsoline-type alkaloids (10–11 with variations at N2 and C3 positions with respect to the natural Compound 2, obtained by a synthetic strategy that involves the Bischler-Napieralski cyclization. The substrate for the condensation to the tetrahydroisoquinoline system, i.e., a functionalized β-arylethyl amine, was obtained through an original double reduction of nitroalkene. The synthetic strategy can be directed to the construction of highly substituted and functionalized 1,2,3,4-tetrahydroisoquinolines.

  4. Optimal ordering quantities for substitutable deteriorating items under joint replenishment with cost of substitution

    Science.gov (United States)

    Mishra, Vinod Kumar

    2017-09-01

    In this paper we develop an inventory model, to determine the optimal ordering quantities, for a set of two substitutable deteriorating items. In this inventory model the inventory level of both items depleted due to demands and deterioration and when an item is out of stock, its demands are partially fulfilled by the other item and all unsatisfied demand is lost. Each substituted item incurs a cost of substitution and the demands and deterioration is considered to be deterministic and constant. Items are order jointly in each ordering cycle, to take the advantages of joint replenishment. The problem is formulated and a solution procedure is developed to determine the optimal ordering quantities that minimize the total inventory cost. We provide an extensive numerical and sensitivity analysis to illustrate the effect of different parameter on the model. The key observation on the basis of numerical analysis, there is substantial improvement in the optimal total cost of the inventory model with substitution over without substitution.

  5. Dielectric and impedance study of praseodymium substituted Mg-based spinel ferrites

    Energy Technology Data Exchange (ETDEWEB)

    Farid, Hafiz Muhammad Tahir, E-mail: tahirfaridbzu@gmail.com [Department of Physics, Bahauddin Zakariya, University Multan, 60800 (Pakistan); Ahmad, Ishtiaq; Ali, Irshad [Department of Physics, Bahauddin Zakariya, University Multan, 60800 (Pakistan); Ramay, Shahid M. [College of Science, Physics and Astronomy Department, King Saud University, P.O. Box 2455, 11451 Riyadh (Saudi Arabia); Mahmood, Asif [Chemical Engineering Department, College of Engineering, King Saud University, Riyadh (Saudi Arabia); Murtaza, G. [Centre for Advanced Studies in Physics, GC University, Lahore 5400 (Pakistan)

    2017-07-15

    Highlights: • Magnesium based spinel ferrites were successfully synthesized by sol-gel method. • Dielectric constant shows the normal spinel ferrites behavior. • The dc conductivity are found to decrease with increasing temperature. • The samples with low conductivity have high values of activation energy. • The Impedance decreases with increasing frequency of applied field. - Abstract: Spinel ferrites with nominal composition MgPr{sub y}Fe{sub 2−y}O{sub 4} (y = 0.00, 0.025, 0.05, 0.075, 0.10) were prepared by sol-gel method. Temperature dependent DC electrical conductivity and drift mobility were found in good agreement with each other, reflecting semiconducting behavior. The dielectric properties of all the samples as a function of frequency (1 MHz–3 GHz) were measured at room temperature. The dielectric constant and complex dielectric constant of these samples decreased with the increase of praseodymium concentration. In the present spinel ferrite, Cole–Cole plots were used to separate the grain and grain boundary’s effects. The substitution of praseodymium ions in Mg-based spinel ferrites leads to a remarkable rise of grain boundary’s resistance as compared to the grain’s resistance. As both AC conductivity and Cole–Cole plots are the functions of concentration, they reveal the dominant contribution of grain boundaries in the conduction mechanism. AC activation energy was lower than dc activation energy. Temperature dependence normalized AC susceptibility of spinel ferrites reveals that MgFe{sub 2}O{sub 4} exhibits multi domain (MD) structure with high Curie temperature while on substitution of praseodymium, MD to SD transitions occurs. The low values of conductivity and low dielectric loss make these materials best candidate for high frequency application.

  6. Hexavalent Chromium Substitution Projects

    Science.gov (United States)

    2011-05-12

    Hexavalent Chromium Substitution Projects Date (12 May 2011) Gene McKinley ASC/WNV (937) 255-3596 Gene.McKinley@wpafb.af.mil Aeronautical Systems...valid OMB control number. 1. REPORT DATE 12 MAY 2011 2. REPORT TYPE 3. DATES COVERED 00-00-2011 to 00-00-2011 4. TITLE AND SUBTITLE Hexavalent ...A-10) – AETC (T-6, T-38 and T1A) • Both Cr Primers & Non-Cr primers as well as Cr Surface Treatment – F-22 8 Non- Chrome Tie-coat & touch-up

  7. Co-metabolic formation of substituted phenylacetic acids by styrene-degrading bacteria

    Directory of Open Access Journals (Sweden)

    Michel Oelschlägel

    2015-06-01

    The styrene-degrading strains Rhodococcus opacus 1CP, Pseudomonas fluorescens ST, and the novel isolates Sphingopyxis sp. Kp5.2 and Gordonia sp. CWB2 were investigated with respect to their applicability to co-metabolically produce substituted phenylacetic acids. Isolates were found to differ significantly in substrate tolerance and biotransformation yields. Especially, P. fluorescens ST was identified as a promising candidate for the production of several phenylacetic acids. The biotransformation of 4-chlorostyrene with cells of strain ST was shown to be stable over a period of more than 200 days and yielded about 38 mmolproduct gcelldryweight−1 after nearly 350 days. Moreover, 4-chloro-α-methylstyrene was predominantly converted to the (S-enantiomer of the acid with 40% enantiomeric excess.

  8. Statistical Physics of Complex Substitutive Systems

    Science.gov (United States)

    Jin, Qing

    Diffusion processes are central to human interactions. Despite extensive studies that span multiple disciplines, our knowledge is limited to spreading processes in non-substitutive systems. Yet, a considerable number of ideas, products, and behaviors spread by substitution; to adopt a new one, agents must give up an existing one. This captures the spread of scientific constructs--forcing scientists to choose, for example, a deterministic or probabilistic worldview, as well as the adoption of durable items, such as mobile phones, cars, or homes. In this dissertation, I develop a statistical physics framework to describe, quantify, and understand substitutive systems. By empirically exploring three collected high-resolution datasets pertaining to such systems, I build a mechanistic model describing substitutions, which not only analytically predicts the universal macroscopic phenomenon discovered in the collected datasets, but also accurately captures the trajectories of individual items in a complex substitutive system, demonstrating a high degree of regularity and universality in substitutive systems. I also discuss the origins and insights of the parameters in the substitution model and possible generalization form of the mathematical framework. The systematical study of substitutive systems presented in this dissertation could potentially guide the understanding and prediction of all spreading phenomena driven by substitutions, from electric cars to scientific paradigms, and from renewable energy to new healthy habits.

  9. William Nierenberg: blockbuster. [Recommendations as alternative or substitution fuel

    Energy Technology Data Exchange (ETDEWEB)

    1977-12-01

    An interview with William Nierenberg, Univ. of California, Berkeley and Scripps Institution of Oceanography, elicits the physicist/environmentalist's determination to expedite the application of available technical solutions. His success in penetrating social and institutional barriers is evidenced by his efforts to have methanol accepted as a substitute fuel. Perceiving these barriers as more formidable than the task of finding technological answers to energy problems, he elaborates on the case for methanol, which is widely used in Europe and does not require large investments for research and development. As a clean-burning substitute for low-sulfur oil, methanol's only drawback as a utility fuel has been price. However, he estimates that large-scale production of methanol will make it competitive with other fuels. He also recommends pursuing solar and ocean thermal energy. As a member of EPRI's Advisory Council, his approach to legislation balances environmental concerns with an understanding of practical issues. (DCK)

  10. Molecular pharmacology of 4-substituted glutamic acid analogues at ionotropic and metabotropic excitatory amino acid receptors

    DEFF Research Database (Denmark)

    Bräuner-Osborne, Hans; Nielsen, B; Stensbøl, T B

    1997-01-01

    (subtypes 1alpha and 2), respectively, whereas (S)-4-methyleneglutamic acid showed high but rather non-selective affinity for the (RS)-2-amino-3-(3-hydroxy-5-methylisoxazol-4-yl)propionic acid (AMPA), kainic acid, NMDA and mGlu receptors (subtypes 1alpha and 2). Although none of the compounds were specific......The pharmacology of (2S,4R)-4-methylglutamic acid, (2S,4S)-4-methylglutamic acid and (S)- and (R)-4-methyleneglutamic acids (obtained in high chemical and enantiomeric purity from racemic 4-methyleneglutamic acid by chiral HPLC using a Crownpak CR(+) column), was examined in binding experiments...... using rat brain ionotropic glutamate receptors, and in functional assays using cloned metabotropic glutamate (mGlu) receptors. As a notable result of these studies, (2S,4R)-4-methylglutamic acid and (2S,4S)-4-methylglutamic acid were shown to be selective for kainic acid receptors and mGlu receptors...

  11. Stable nickel-substituted spinel cathode material (LiMn1.9Ni0.1O4) for lithium-ion batteries obtained by using a low temperature aqueous reduction technique

    CSIR Research Space (South Africa)

    Kunjuzwa, Niki

    2016-11-01

    Full Text Available A nickel substituted spinel cathode material (LiMn1.9Ni0.1O4) with enhanced electrochemical performance was successfully synthesized by using a locally-sourced, low-cost manganese precursor, electrolytic manganese dioxide (EMD), and NiSO4·6H2O as a...

  12. Intertextualita a její podíl na vyjednávání pozic účastníků talk show

    Czech Academy of Sciences Publication Activity Database

    Čmejrková, Světla; Hoffmannová, Jana

    2012-01-01

    Roč. 73, č. 4 (2012), s. 263-284 ISSN 0037-7031 R&D Projects: GA ČR GAP406/12/1829 Institutional support: RVO:68378092 Keywords : political discourse * intertextuality * talk shaw * polyphony * irony * parody Subject RIV: AI - Linguistics Impact factor: 0.233, year: 2012

  13. General-base catalysed hydrolysis and nucleophilic substitution of activated amides in aqueous solutions

    NARCIS (Netherlands)

    Buurma, NJ; Blandamer, MJ; Engberts, JBFN; Buurma, Niklaas J.

    The reactivity of 1-benzoyl-3-phenyl-1,2,4-triazole (1a) was studied in the presence of a range of weak bases in aqueous solution. A change in mechanism is observed from general-base catalysed hydrolysis to nucleophilic substitution and general-base catalysed nucleophilic substitution. A slight

  14. Influence of diluent alkyl substitution on the extraction of Am(III) and Eu(III) by a 6,6'-bis(1,2,4-triazin-3-yl)-2,2'-bipyridine ligand dissolved in alkylated cyclohexanone diluents

    Energy Technology Data Exchange (ETDEWEB)

    Distler, P.; Spendlikova, I. [Czech Technical Univ., Prague (Czech Republic). Dept. of Nuclear Chemistry; John, J. [Czech Technical Univ., Prague (Czech Republic). Dept. of Nuclear Chemistry; Czech Technical Univ., Prague (Czech Republic). Centre for Radiochemistry and Radiation Chemistry; Harwood, L.M.; Hudson, M.J.; Lewis, F.W. [Reading Univ., Berkshire (United Kingdom). Dept. of Chemistry

    2012-07-01

    Several alkylated cyclohexanones were investigated as potential diluents for the selective extraction of Am(III) from Eu(III) from nitric acid solutions by the CyMe{sub 4}-BTBP ligand. No significant extraction of either of the metal ions was observed for these diluents themselves. In the extractions from 1 M HNO{sub 3}, 3-methylcyclohexanone and 4-methylcyclohexanone gave comparable results to cyclohexanone whereas in the extractions from 4 M HNO{sub 3}, 2-methylcyclohexanone, 3-methylcyclohexanone and 4-methylcyclohexanone all gave superior results. For the monomethylated diluents, D{sub Am} and SF{sub Am/Eu} decreased in the order of alkyl substitution 2 > 4 {proportional_to} 3. However, alkyl substitution of cyclohexanone significantly slows down the extraction kinetics compared to cyclohexanone, and the position of alkyl substitution was found to play an important role in the solvents properties. 3-Methylcyclohexanone was identified as the most promising of the diluents. (orig.)

  15. Biologic and synthetic skin substitutes: An overview.

    Science.gov (United States)

    Halim, Ahmad Sukari; Khoo, Teng Lye; Mohd Yussof, Shah Jumaat

    2010-09-01

    The current trend of burn wound care has shifted to more holistic approach of improvement in the long-term form and function of the healed burn wounds and quality of life. This has demanded the emergence of various skin substitutes in the management of acute burn injury as well as post burn reconstructions. Skin substitutes have important roles in the treatment of deep dermal and full thickness wounds of various aetiologies. At present, there is no ideal substitute in the market. Skin substitutes can be divided into two main classes, namely, biological and synthetic substitutes. The biological skin substitutes have a more intact extracellular matrix structure, while the synthetic skin substitutes can be synthesised on demand and can be modulated for specific purposes. Each class has its advantages and disadvantages. The biological skin substitutes may allow the construction of a more natural new dermis and allow excellent re-epithelialisation characteristics due to the presence of a basement membrane. Synthetic skin substitutes demonstrate the advantages of increase control over scaffold composition. The ultimate goal is to achieve an ideal skin substitute that provides an effective and scar-free wound healing.

  16. Biologic and synthetic skin substitutes: An overview

    Directory of Open Access Journals (Sweden)

    Halim Ahmad

    2010-10-01

    Full Text Available The current trend of burn wound care has shifted to more holistic approach of improvement in the long-term form and function of the healed burn wounds and quality of life. This has demanded the emergence of various skin substitutes in the management of acute burn injury as well as post burn reconstructions. Skin substitutes have important roles in the treatment of deep dermal and full thickness wounds of various aetiologies. At present, there is no ideal substitute in the market. Skin substitutes can be divided into two main classes, namely, biological and synthetic substitutes. The biological skin substitutes have a more intact extracellular matrix structure, while the synthetic skin substitutes can be synthesised on demand and can be modulated for specific purposes. Each class has its advantages and disadvantages. The biological skin substitutes may allow the construction of a more natural new dermis and allow excellent re-epithelialisation characteristics due to the presence of a basement membrane. Synthetic skin substitutes demonstrate the advantages of increase control over scaffold composition. The ultimate goal is to achieve an ideal skin substitute that provides an effective and scar-free wound healing.

  17. Germany’s Anschluss with Austria and Russia’s Annexation of Crimea: An Analytical Comparison

    Science.gov (United States)

    2016-06-01

    state of Ukraine was a product of World War I and the dissolution of the empires that had ruled it. Ukrainians were not referred to as such until...crowds of thousands of voters wielding multiple absentee 209 Shaw, “Crimea: Background and

  18. Synthesis of Randomly Substituted Anionic Cyclodextrins in Ball Milling

    Directory of Open Access Journals (Sweden)

    László Jicsinszky

    2017-03-01

    Full Text Available A number of influencing factors mean that the random substitution of cyclodextrins (CD in solution is difficult to reproduce. Reaction assembly in mechanochemistry reduces the number of these factors. However, lack of water can improve the reaction outcomes by minimizing the reagent’s hydrolysis. High-energy ball milling is an efficient, green and simple method for one-step reactions and usually reduces degradation and byproduct formation. Anionic CD derivatives have successfully been synthesized in the solid state, using a planetary ball mill. Comparison with solution reactions, the solvent-free conditions strongly reduced the reagent hydrolysis and resulted in products of higher degree of substitution (DS with more homogeneous DS distribution. The synthesis of anionic CD derivatives can be effectively performed under mechanochemical activation without significant changes to the substitution pattern but the DS distributions were considerably different from the products of solution syntheses.

  19. Synthesis and In Vitro Antiproliferative Activity of Novel Phenyl Ring-Substituted 5-Alkyl-12(H-quino[3,4-b][1,4]benzothiazine Derivatives

    Directory of Open Access Journals (Sweden)

    Andrzej Zięba

    2016-11-01

    Full Text Available A novel series of tetracyclic quinobenzothiazine derivatives was synthetized. Compounds containing a substituent (hydroxyl, methyl, phenyl, piperidyl, or piperazinyl in positions 9 and 11 were obtained by cyclization of suitable 4-aminoquinolinium-3-thiolates. Quinobenzothiazine 10-O-substituted derivatives were obtained by alkylating the hydroxyl group in position 10 of the parent (quinobenzothiazine system. Antiproliferative activity of the synthesized compounds was studied using cultured neoplastic cells (MDA-MB-231, SNB-19, and C-32 cell lines. Four selected compounds were investigated in more detail for cytotoxicity and antiproliferative effect. Transcriptional activity of genes regulating cell cycle (TP53, apoptosis (BAX, BCL-2, as well as proliferation (H3 were assessed. Finally, the ability of the selected compounds to bind DNA was checked in the presence of ethidium bromide.

  20. Evaluation of structural, morphological and magnetic properties of CuZnNi (Cu_xZn_0_._5_−_xNi_0_._5Fe_2O_4) nanocrystalline ferrites for core, switching and MLCI’s applications

    International Nuclear Information System (INIS)

    Akhtar, Majid Niaz; Khan, Muhammad Azhar; Ahmad, Mukhtar; Nazir, M.S.; Imran, M.; Ali, A.; Sattar, A.; Murtaza, G.

    2017-01-01

    The influence of Cu substitution on the structural and morphological characteristics of Ni–Zn nanocrystalline ferrites have been discussed in this work. The detailed and systematic magnetic characterizations were also done for Cu substituted Ni–Zn nanoferrites. The nanocrystalline ferrites of Cu substituted Cu_xZn_0_._5_−_xNi_0_._5Fe_2O_4 ferrites (x=0, 0.1, 0.2, 0.3, 0.4 and 0.5) were synthesized using sol gel self-combustion hybrid method. X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), Transmission electron microscope (TEM) and Vibrating sample magnetometer (VSM) were used to investigate the properties of Cu substituted nanocrystalline ferrites. Single phase structure of Cu substituted in Ni–Zn nanocrystalline ferrites were investigated for all the samples. Crystallite size, lattice constant and volume of the cell were found to increase by increasing Cu contents in spinel structure. The better morphology with well-organized nanocrystals of Cu–Zn–Ni ferrites at x=0 and 0.5 were observed from both FESEM and TEM analysis. The average grain size was 35–46 nm for all prepared nanocrystalline samples. Magnetic properties such as coercivity, saturation, remanence, magnetic squareness, magneto crystalline anisotropy constant (K) and Bohr magneton were measured from the recorded M–H loops. The magnetic saturation and remanence were increased by the incorporation of Cu contents. However, coercivity follow the Stoner-Wolforth model except for x=0.3 which may be due to the site occupancy and replacement of Cu contents from octahedral site. The squareness ratio confirmed the super paramgnetic behaviour of the Cu substituted in Ni–Zn nanocrystalline ferrites. Furthermore, Cu substituted Ni–Zn nanocrystalline ferrites may be suitable for many industrial and domestic applications such as components of transformers, core, switching, and MLCI’s due to variety of the soft magnetic characteristics. - Highlights: • Cu substituted