Copper-catalysed selective hydroamination reactions of alkynes

The development of selective reactions that utilize easily available and abundant precursors for the efficient synthesis of amines is a long-standing goal of chemical research. Despite the centrality of amines in a number of important research areas, including medicinal chemistry, total synthesis and materials science, a general, selective and step-efficient synthesis of amines is still needed. Here, we describe a set of mild catalytic conditions utilizing a single copper-based catalyst that enables the direct preparation of three distinct and important amine classes (enamines, α-chiral branched alkylamines and linear alkylamines) from readily available alkyne starting materials with high levels of chemo-, regio- and stereoselectivity. This methodology was applied to the asymmetric synthesis of ​rivastigmine and the formal synthesis of several other pharmaceutical agents, including ​duloxetine, ​atomoxetine, ​fluoxetine and ​tolterodine.National Institutes of Health (U.S.) (GM58160

Regional in vivo transit time measurements of aortic pulse wave velocity in mice with high-field CMR at 17.6 Tesla

<p>Abstract</p> <p>Background</p> <p>Transgenic mouse models are increasingly used to study the pathophysiology of human cardiovascular diseases. The aortic pulse wave velocity (PWV) is an indirect measure for vascular stiffness and a marker for cardiovascular risk.</p> <p>Results</p> <p>This study presents a cardiovascular magnetic resonance (CMR) transit time (TT) method that allows the determination of the PWV in the descending murine aorta by analyzing blood flow waveforms. Systolic flow pulses were recorded with a temporal resolution of 1 ms applying phase velocity encoding. In a first step, the CMR method was validated by pressure waveform measurements on a pulsatile elastic vessel phantom. In a second step, the CMR method was applied to measure PWVs in a group of five eight-month-old apolipoprotein E deficient (ApoE^(-/-)) mice and an age matched group of four C57Bl/6J mice. The ApoE^(-/-)group had a higher mean PWV (PWV = 3.0 ± 0.6 m/s) than the C57Bl/6J group (PWV = 2.4 ± 0.4 m/s). The difference was statistically significant (p = 0.014).</p> <p>Conclusions</p> <p>The findings of this study demonstrate that high field CMR is applicable to non-invasively determine and distinguish PWVs in the arterial system of healthy and diseased groups of mice.</p

Echanges commerciaux de produits agricoles : conflits et compromis

[fre] Le système mondial, ouvert et organisé, d'échanges agricoles est en voie de détérioration. La crise économique et les propres faiblesses du système en sont la cause. La structure des échanges est influencée par les politiques agricoles nationales, et les Négociations du Kennedy et du Tokyo Rounds n'ont pas réussi à libéraliser le commerce agricole. Les secrétariats du GATT et de l'OCDE conduisent des travaux sur le protectionnisme qui pourraient clarifier les enjeux de futures négociations. . Ce sont les Etats-Unis qui poussent le plus aux réformes ; mécontents de l'état de leurs exportations, ils en reportent la responsabilité sur la PAC. Des suggestions sont avancées sur des mesures susceptibles d'aplanir les désaccords et de résoudre certains problèmes de l'organisation actuelle des échanges. La profession des Economistes Ruraux doit contribuer à clarifier les débats en conduisant les travaux théoriques et appliqués nécessaires. Les Politiques nationales étant prédominantes dans la détermination des échanges, leur réforme mérite un examen particulier. [eng] The open and rule-oriented world agricultural trading system is deteriorating due to the recession and its embodied weaknesses. The patterns of trade flows are mainly influenced by state policies and the Kennedy Round and Tokyo Round Negotiations have failed to make agricultural trade more liberal. Both GATT and OECD Secretariats are carrying studies that may clarify the issues for future negotiations. The current pressure for change comes from US discontent with its world agricultural trade and the EC policy is caught under fire. The types of measure able to alleviate the disputes and help solving some of the Agricultural trade problems are reviewed. The agricultural economics profession should feel concerned with developping analyses, theoretical and empirical, so that negotiators are better informed. National policies are most important for agricultural trade and domestic farm programs need to be scrutinized.