- Large Converse Piezoelectric Effect Measured on a Single Molecule on a Metallic Surface
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The converse piezoelectric effect is a phenomenon in which mechanical strain is generated in a material due to an applied electrical field. In this work, we demonstrate the converse piezoelectric effect in single heptahelicene-derived molecules on the Ag(111) surface using atomic force microscopy (AFM) and total energy density functional theory (DFT) calculations. The force-distance spectroscopy acquired over a wide range of bias voltages reveals a linear shift of the tip-sample distance at which the contact between the molecule and tip apex is established. We demonstrate that this effect is caused by the bias-induced deformation of the spring-like scaffold of the helical polyaromatic molecules. We attribute this effect to coupling of a soft vibrational mode of the molecular helix with a vertical electric dipole induced by molecule-substrate charge transfer. In addition, we also performed the same spectroscopic measurements on a more rigid o-carborane dithiol molecule on the Ag(111) surface. In this case, we identify a weaker linear electromechanical response, which underpins the importance of the helical scaffold on the observed piezoelectric response.
- Stetsovych, Oleksandr,Mutombo, Pingo,?vec, Martin,?ámal, Michal,Nejedly, Jind?ich,Císa?ová, Ivana,Vázquez, Héctor,Moro-Lagares, María,Berger, Jan,Vacek, Jaroslav,Stará, Irena G.,Stary, Ivo,Jelínek, Pavel
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Read Online
- METHODS FOR MAKING QUINOLINYLDIAMINES
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The present disclosure provides methods for making quinolinyldiamine products from quinolinyl starting materials. In addition, the quinolinyldiamines can be used as ligands or ligand precursors for catalysts, e.g. for use in olefin polymerization.
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- Spirobifluorene-based Porous Organic Polymers as Efficient Porous Supports for Pd and Pt for Selective Hydrogenation
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Spirobifluorene-based porous organic polymers (POP) were synthesized following two different protocols; the acetylenic coupling reaction conditions and the Sonogashira cross-coupling reaction. These were utilized as support for the hydrogenation of a series of species containing unsaturated C=C and C=O bonds (4-nitrostyrene, 4-bromobenzophenone, acetophenone, 7-nitro-1-tetralone and 1,2-naphtoquinone confirmed their efficiency). POP1 prepared via a copper-catalysis protocol was completely inactive, while POP2-4 containing residual Pd exhibited different activities in accordance to the accessibility of the substrates to the metal. Further deposition of 0.5 wt% Pd led to active and stable catalysts. They were easily separated by filtration, and after re-dispersion, afforded the same performances for ten successive cycles. This study also evidenced the specific role of the support in these reactions by comparing the behavior of Pd/POP with that of a Pd/C catalyst with the same loading of palladium. The deposition of Pt on these supports led to sub-nanometric particles and, in accordance, to a different catalytic behavior reflected merely by differences in the selectivity.
- Trandafir, Mihaela Mirela,Pop, Lidia,H?dade, Niculina D.,Hristea, Ioana,Teodorescu, Cristian Mihail,Krumeich, Frank,van Bokhoven, Jeroen A.,Grosu, Ion,Parvulescu, Vasile I.
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p. 538 - 549
(2018/10/09)
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- 2,4-Pyrimidinediamine Compounds and Their Uses
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The present invention provides 2,4-pyrimidinediamine compounds that inhibit the IgE and/or IgG receptor signaling cascades that lead to the release of chemical mediators, intermediates and methods of synthesizing the compounds and methods of using the compounds in a variety of contexts, including in the treatment and prevention of diseases characterized by, caused by or associated with the release of chemical mediators via degranulation and other processes effected by activation of the IgE and/or IgG receptor signaling cascades.
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Paragraph 0485; 0467
(2015/11/10)
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- Development of sulfonamide compounds as potent methionine aminopeptidase type II inhibitors with antiproliferative properties
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We have screened molecules for inhibition of MetAP2 as a novel approach toward antiangiogenesis and anticancer therapy using affinity selection/mass spectrometry (ASMS) employing MetAP2 loaded with Mn2+ as the active site metal. After a series
- Kawai, Megumi,BaMaung, Nwe Y.,Fidanze, Steve D.,Erickson, Scott A.,Tedrow, Jason S.,Sanders, William J.,Vasudevan, Anil,Park, Chang,Hutchins, Charles,Comess, Kenneth M.,Kalvin, Douglas,Wang, Jieyi,Zhang, Qian,Lou, Pingping,Tucker-Garcia, Lora,Bouska, Jennifer,Bell, Randy L.,Lesniewski, Richard,Henkin, Jack,Sheppard, George S.
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p. 3574 - 3577
(2007/10/03)
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- Sulfonamides having antiangiogenic and anticancer activity
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Compounds having methionine aminopeptidase-2 inhibitory (MetAP2) are described. Also described are pharmaceutical compositions comprising the compounds, methods of treatment using the compounds, methods of inhibiting angiogenesis, and methods of treating cancer.
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- Benzocycloalkene compounds, their production and use
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A compound of the formula wherein R1and R2are H, a hydrocarbon group or a heterocyclic group, or R1and R2are combinedly a spiro ring; R3is a hydrocarbon group, a substituted amino group, a substituted
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- Amidino derivatives and their use as thrombin inhibitors
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There is provided compounds of formula I, wherein R1, Rx, Y, Ry, n and B have meanings given in the description which are useful as competitive inhibitors of trypsin-like proteases, such as thrombin, and in particular in the treatment of conditions where inhibition of thrombin is required (e.g. thrombosis) or as anticoagulants.
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- Benzo-fused lactams that promote the release of growth hormone
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There are disclosed certain novel compounds identified as benzo-fused lactams which promote the release of growth hormone in humans and animals. This property can be utilized to promote the growth of food animals to render the production of edible meat products more efficient, and in humans, to increase the stature of those afflicted with a lack of a normal secretion of natural growth hormone. Growth promoting compositions containing such benzo-fused lactams as the active ingredient thereof are also disclosed.
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- Nitrogen-containing heterocyclic compounds as class III antiarrhythmic agents
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Compounds of structural formula: STR1 wherein Ar is an aromatic ring, B is a cyclic moiety fused to Ar of 5-7 members, X and Y are bridging groups, Q is a nitrogen containing heterocycle, R2 and R3 are H, substituted or unsubtituted C1-3 alkyl, C1-3 alkoxy, N(R)2, halogen, CF3 or R5 and R1 is H or an aryl group.
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- Carbocyclic compounds useful as leukotriene antagonists
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This invention comprises novel carbocyclic compounds of formula I (wherein A, Z, R11 and R12 are defined in the specification) derived from acylsulfonamide derivatives of α-carbocyclyltoluic acids wherein said compounds of formula I antagonize the actions of one or more of the arachidonic acid metabolites known as leukotrienes. The invention also provides pharmaceutically acceptable salts of the formula I compounds; pharmaceutical compositions containing the formula I compound, or their salts, for use in the treatment of, for example, allergic or inflammatory diseases, or endotoxic or traumatic shock conditions; and processes for the manufacture of the formula I compounds, as well as intermediates for use in such manufacture.
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- Nitrogens containing heterocyclic compounds as class III antiarrhythmic agents
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Compounds of structural formula: STR1 wherein Ar is an aromatic ring, B is a cyclic moiety fused to Ar of 5-7 members and Q is a nitrogen containing heterocycle, are antiarrhythmic agents.
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- Monoquaternary neuromuscular blocking agents based on 1 tetralone and 1 indanone
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The preparation of three isomeric 1 tetralone hydrazones and three isomeric 1 indanone hydrazones possessing a single quaternary ammonium center is described. Several of the compounds possessed significant neuromuscular blocking activity, and two approached suxamethonium in potency. 1H NMR evidence obtained from a study of the N,N dimethylhydrazones indicated that the hydrazones adopted an E configuration in solution.
- Biggs,Casy,Chu,Coutts
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p. 472 - 475
(2007/10/06)
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