To examine patterns of strategy choice and discovery during problem-solving of a novel locomotor task, 13.5- and 18-month-old infants were placed at the top of a staircase and encouraged to descend. Spontaneous stair descent strategy choices were documented step by step and trial by trial to provide a microgenetic account of problem-solving in action.
View Article and Find Full Text PDFThe alpha2beta1 integrin receptor plays a key role in angiogenesis. Here we investigated the effects of small molecule inhibitors (SMIs) designed to disrupt integrin alpha2 I or beta1 I-like domain function on angiogenesis. In unchallenged endothelial cells, fibrillar collagen induced robust capillary morphogenesis.
View Article and Find Full Text PDFThere is a grave need for safer antiplatelet therapeutics to prevent heart attack and stroke. Agents targeting the interaction of platelets with the diseased vessel wall could impact vascular disease with minimal effects on normal hemostasis. We targeted integrin alpha(2)beta(1), a collagen receptor, because its overexpression is associated with pathological clot formation whereas its absence does not cause severe bleeding.
View Article and Find Full Text PDF[reaction: see text] The first catalytic, enantioselective addition of organozinc reagents to alpha-aldiminoesters is described. The use of a Lewis acid/Lewis base containing bifunctional catalyst preorganizes both reactive substrates to promote enantioselective addition over the racemic background reaction and alternative addition modes. Alcohol additives were found to enhance the enantioselection.
View Article and Find Full Text PDFThe unsymmetrical, optically active ligands 1,2-C(6)H(4)(PPh(2))((R,R)-2,5-dimethylphospholanyl) and the new 1,1'-Fe(C(5)H(4))(2)(PPh(2))((R,R)-2,5-dimethylphospholanyl) form complexes of the type [PtCl(2)(diphos)] and [Rh(diphos)(diene)][BF(4)]. The crystal structure of reveals that only one quadrant is blocked. Asymmetric hydrogenation of acrylic esters and enamides using and as catalysts show that the phenylene-backboned diphosphine gives a more efficient catalyst in terms of asymmetric induction than the more flexible ferrocene-backboned diphosphine.
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