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951.
Lepailleur A Bureau R Paillet-Loilier M Fabis F Saettel N Lemaître S Dauphin F Lesnard A Lancelot JC Rault S 《Journal of chemical information and modeling》2005,45(4):1075-1081
The present study discusses the well-known 5-HT7/5-HT1A selectivity issue through a new series of phenylpyrrole derivatives. The first hits emerged from a virtual screening performed on a chemolibrary. Further study led to an optimization of a preliminary 5-HT7 pharmacophore model. The importance of each pharmacophoric feature is confirmed, but these characteristics have to be coupled to geometric constraints in order to achieve a 5-HT7 selectivity. Indeed, 5-HT1A affinity probably arises from extended conformations, whereas a bent one appears to be best suited for 5-HT7 selectivity. 相似文献
952.
Lepareur N Mévellec F Noiret N Refosco F Tisato F Porchia M Bandoli G 《Dalton transactions (Cambridge, England : 2003)》2005,(17):2866-2875
Reduction-substitution reactions of [M(O)Cl(4)](-)(M=Re, (99)Tc) precursors with an excess of substituted dithiobenzoate ligands (R-PhCS(2))(-) in dichloromethane/methanol mixtures afford a series of six-coordinated neutral mixed-ligand complexes of the type M(III)(R-PhCS(3))(2)(R-PhCS(2))(M=Re; Rel--9; M=99)Tc; Tel--9). The coordination sphere is entirely filled by sulfur donor atoms, and the complexes adopt a distorted trigonal prismatic arrangement, as assessed by the X-ray crystal structure analysis of Re(4-Me-PhCS(3))(2)(4-Me-PhCS(2)), Re 2. These compounds show sharp proton and carbon NMR profiles, in agreement with the diamagnetism typical of low spin d(4) trigonal prismatic configurations. The red-ox processes involve reduction of the metal from Re(v) to Re(iii) and oxidation of dithiobenzoate to trithioperoxybenzoate. M2--9 complexes contain a substitution-inert [M(R-PhCS(3))(2)](+) moiety including the metal and two trithioperoxybenzoate fragments, while the third dithiobenzoate ligand is labile. The latter is efficiently replaced by reaction with better nucleophiles such as diethyldithiocarbamate giving a further class of mixed ligand complexes of the type M(III)(R-PhCS(3))(2)(Et(2)NCS(2))(M=Re; Re 10--18; M=(99)Tc; Tc--18), which retain the trigonal prismatic arrangement, as determined by the X-ray analyses of the representative compounds Re(PhCS(3))(2)(Et(2)NCS(2)), Re 10 and (99)Tc(PhCS(3))(2)(Et(2)NCS(2)), Tc 10. 相似文献
953.
Nicolas?FournierEmail author Philippe?Lauren?ot 《Communications in Mathematical Physics》2005,256(3):589-609
The existence of self-similar solutions to Smoluchowskis coagulation equation has been conjectured for several years by physicists, and numerical simulations have confirmed the validity of this conjecture. Still, there was no existence result up to now, except for the constant and additive kernels for which explicit formulae are available. In this paper, the existence of self-similar solutions decaying rapidly at infinity is established for a wide class of homogeneous coagulation kernels. 相似文献
954.
Chiral lactones were synthesized in six steps from d-mannitol. The key-step was a domino ring-closing metathesis reaction leading to the symmetric cleavage of a d-mannitol triene derivative and to the formation of two molecules of the desired lactone. 相似文献
955.
A model, based on concepts from the theory of atom-surface accommodation coefficients, for nonequilibrium desorption of atoms and molecules from surfaces is proposed. We contend that the nonequilibrium effects should be expected to be general properties of not only polyatomic molecule-surface systems, but of all desorbing systems. The model predicts large deviations from the equilibrium dependences, on desorption angle, of (a) the desorbing atomic flux, (b) the average energy of desorbing atoms and (c) the desorbing atomic speed ratio. The deviations are larger when the accommodation coefficient is smaller. 相似文献
956.
Nicolas Bouleau 《Bulletin des Sciences Mathématiques》2005,129(5):369
We use the language of errors to handle local Dirichlet forms with squared field operator (cf. [N. Bouleau, Error Calculus for Finance and Physics, the Language of Dirichlet Forms, De Gruyter, 2003]). Let us consider, under the hypotheses of Donsker theorem, a random walk converging weakly to a Brownian motion. If, in addition, the random walk is supposed to be erroneous, the convergence occurs in the sense of Dirichlet forms and induces the Ornstein-Uhlenbeck structure on the Wiener space. This quite natural result uses an extension of Donsker theorem to functions with quadratic growth. As an application we prove an invariance principle for the gradient of the maximum of the Brownian path computed by Nualart and Vives. 相似文献
957.
A macroscopic thermodynamical theory of unsaturated porous media is studied. The porous media under consideration contain air, liquid water and its vapour encountering phase changes. To the classical state quantities, viz. temperature and densities, we add the volume fractions. These fractions are submitted to constraints, for instance their values lie between 0 and 1. The constraints are taken into account by the free energies which become non-smooth functions. The constitutive laws are obtained by classical thermodynamics and a careful treatment of the non-smooth functions. The constitutive laws account for experimental properties of unsaturated porous media: hysteresis of the sorption and desorption, capillary suction ... 相似文献
958.
Nicolas Bouleau 《Probability Theory and Related Fields》1982,61(2):283-290
Sans résumé 相似文献
959.
Summary The structure of the support F of an idempotent probability measure on a locally compact semigroup S is considered. It is shown that if S satisfies the condition (L): AB
–1 is compact whenever A and B are compact subsets of S, then F is a completely simple semigroup and has the canonical representation X ×G×Y of which G and Y are compact. Moreover, is a product measure
X
×
G
×
Y
where
X
and
Y
are probability measures and
G
is the Haar measure on the group G. We conjecture that a similar result remains true even without the condition (L). We give also a relation between our conjecture and a conjecture of Argabright on the support of an r
*-invariant measure. 相似文献
960.
Summary Differential calculus is proving inefficient to solve problems of mechanics dealing with ropes, unless one satisfies oneself with rough approximations.Ordinary or Euclidean geometry is also proving useless: The author shows that in order to solve such problems as described before, one has to use a special branch of geometry. Distances are no longer measured along rigid straight rules, but along the catenary curves in question.The fundamental characteristics of this hypergeometry, with some of their more striking results, are described in the following study. 相似文献