Search results for "stereo"

In silico prediction of central nervous system activity of compounds. Identification of potential pharmacophores by the TOPS–MODE approach

2004

The central nervous system (CNS) activity has been investigated by using a topological substructural molecular approach (TOPS-MODE). A discriminant analysis to classify CNS and non-CNS drugs was developed on a data set (302 compounds) of great structural variability where more than 81% (247/302) were well classified. Randic's orthogonalization procedures was carried out to allow the interpretation of the model and to avoid the collinearity among descriptors. The discriminant model was assessed by a leave-n-out (when n varies from 2 to 20) cross-validation procedure (79.94% of correct classification), an external prediction set composed by 78 CNS/non-CNS drugs (80.77% of correct classificati…

Improved technique for stereotactic placement of nerve grafts between two locations inside the rat brain

2008

Peripheral nerve grafts have shown the ability to facilitate central axonal growth and regenerate the adult central nervous system. However, the detailed description of a technique for atraumatic graft placement within the brain is lacking. We present a stereotactic procedure to implant a peripheral nerve graft within a rat's brain with minimal brain tissue damage. The procedure permits a correct graft placement joining two chosen points, and the survival and integration of the graft in the host tissue with a light glial reaction, with evidence of central axonal growth inside the graft, at least up to 8 weeks after its implantation. (C) 2008 Elsevier B.V. All rights reserved.

Halogenated derivatives of boldine with high selectivity for alpha1A-adrenoceptors in rat cerebral cortex.

1999

The selectivity of 3-nitrosoboldine and different halogenated derivatives of boldine (3-bromoboldine, 3,8-dibromoboldine and 3-chloroboldine) for alpha1-adrenoceptor subtypes was studied by examining [3H]-prazosin competition binding in rat cerebral cortex. In the competition experiments [3H]-prazosin binding was inhibited completely by all the compounds tested. The inhibition curves displayed shallow slopes which could be subdivided into high and low affinity components. The relative order of affinity and selectivity for alpha1A-adrenoceptors was 3-bromoboldine = 3,8-dibromoboldine = 3-chloroboldineboldine3-nitrosoboldine. The competition curves for 3-bromoboldine remained shallow and biph…

The role of the claustrum in the bilateral control of frontal oculomotor neurons in the cat.

1991

The effect of claustrum (CL) stimulation on the spontaneous unitary activity of ipsi and contralateral frontal oculomotor neurons, was studied in chloralose-anaesthetized cats. A total of 205 units was bilaterally recorded in the medial oculomotor area, homologous of the primate "frontal eye fields"; 127 neurons were identified as projecting to the superior colliculus; for 33 of these last units stimulation of the ipsilateral CL provoked an excitatory effect lasting 10-25 ms and appearing with a latency of 5-15 ms; on 8 units the excitatory effect was followed by an inhibition lasting 100-250 ms. Ninety-eight of the 127 neurons were also tested through activation of the contralateral CL: 13…

S-Methylisothioharnstoffe, Bausteine kettenverzweigter Cimetidin-DerivateS-Methylisothioureas, Synthons for Chain-Branched Cimetidine Derivates

1987

A partir de S,S-dimethyl N-cyano dithiocarbonimidate et d'amino-2' alkyl (ramifie) thiomethyl-4 methyl-5 imidazoles (A), synthese des derives de A substitues sur l'amino-2' par [cyanoimino methylthiomethyle]

ChemInform Abstract: o-(Hydroxyalkyl)phenyl P-Chirogenic Phosphines as Functional Chiral Lewis Bases.

2013

The stereoselective synthesis of P-chirogenic phosphines bearing an o-hydroxyalkyl chain is described.

ChemInform Abstract: A Series of Calix(4)arenes, Having Two Opposite Para Positions Connected by an Aliphatic Chain.

1989

Röntgenographische untersuchungen an linearen oligourethanen

1961

Zwei polymerhomologe Reihen von Diol-oligo-urethanen wurden rontgenographisch untersucht. Die vor allem im Kleinwinkelbereich durchgefuhrten Messungen fuhrten zu dem Ergebnis, das die gefundenen Langperioden bis zum Diol-okta-urethan eine Funktion des Molekulargewichtes sind und dann uber einen weiten Molekulgrosenbereich bis zum Polymeren einschlieslich konstant bleiben. Two homologous polymeric series of diol-oligo-urethanes were studied by X-rays, particularly in the small-angle range. Up to a certain chain length (diol-octa-urethanes) the observed long periods are a function of the molecular weight. Then they remain constant over a wide range up to the polymer inclusively.

1979

The demixing behavior of 20 representatives of the system oligo(dimethylsiloxane)/oligo(propylene glycol) (ODMS/OPG)1 is investigated at pressures up to 1 500 bar. The degrees of oligomerization range from 2 to 5 for the first and from 1 to 57, 6 for the second component. The experimental results are compared with those for the previously studied system oligoisobutene/oligo(propylene glycol) (OIB/OPG). In both cases the observed upper critical temperatures Tc increase with the number of monomeric units of the less polar component, whereas they run through a minimum when the number of monomeric units of the glycol is raised. For the present system the Tc values are found to be considerably h…

A rare example of nickel(ii) chains based on a heteroscorpionate-like ligand with quadruple imidazolyl interactions

2014

The first nickel(ii) complex with the heteroscorpionate-like bridging ligand DIMMAL (2-di1H-2-imidazolylmethylmalonate), [Ni(DIMMAL)(H2O)3]n·3nH2O (1), is a one-dimensional coordination polymer whose structure shows regular Ni(ii) chains with H-bonding inter-chain interactions and a rare example of a Quadruple Imidazolyl Embrace (QIE). The Ni(ii) chain shows a weak antiferromagnetic interaction that can be modelled with a regular S = 1 chain model including a zero field splitting with g = 2.270, J = -1.5 cm(-1) and D = -2.26 cm(-1).