1,720,998 research outputs found
Efficacy and safety of hypertonic saline solutions in the treatment of severe head injury.
No full textSynthesis and characterization of group 4 constrained geometry complexes containing a linked cyclopentadienyl-o-carboranyl ligand
No full textNovel linked cyclopentadienyl-o-carboranyl group 4 metal complexes, [eta (5):eta (1)-Me2Si(C5Me4)(C2B10H10]TiCl2 (2) and [eta (5):eta (1)-Me2Si(C5Me4)(C2B10H10)]Zr(NMe2)(2) (3), have been prepared via salt metathesis and amine elimination. reactions utilizing the linked o-carboranyl ligand, Me2Si(C5Me4H)(C2B10H11) (1). Their X-ray crystal structures are reported.The financial support from the
Korea Science and Engineering Foundation and the
Brain Korea 21 Project are gratefully acknowledged
Successful resuscitation of acute massire pulmonary embolism with extracorporeal membrane oxygenation and open embolectomy.
No full textDelayed diagnosis of esophageal perforation following intraoperative transesophageal echocardiography during valvular replacement--- a cae report.
No full textNeglected esophageal injury presenting with spontaneously shrunken retroesophageal pocket
No full textColor doppler ultrasonography in detecting transdiaphragmatic flow of hepatic hydrothorax: correlated with thoracoscopic findings
No full textIsospecific propylene polymerization by C-1-symmetric Me2Si(C5Me4)(2-R-Ind)MCl2 (M = Ti, Zr) complexes
No full textNovel Cl-symmetric group 4 ansa-metallocene complexes Me2Si(C5Me4)(2-R-Ind)MCl2 (R = H, M = Ti (5a), Zr (5b); R = Me, M = Ti (6a), Zr (6b)) were prepared from the reaction of dilithium salt of the corresponding ligands Me2Si(C5Me4H)(2-R-IndH) (R = H, Me) with appropriate group 4 metal halides. Crystal structures of 5a, 6a, and 6b determined by X-ray diffraction studies reveal chiral C-1-symmetric nature irrespective of the type of metal ana ligand. The complexes 5a, 5b, 6a, and 6b were tested for the polymerization of propylene in the presence of methylaluminoxane (MAO) at various temperatures. All of them exhibit good activity and afford moderate to high isotactic polypropylenes. In the case of titanocenes (5a and 6a), polymerization activity, molecular weight, and isotacticity of polypropylene sharply increase as the polymerization temperature decreases, while the increase of polymerization activity and the decrease of isotacticity and molecular weight of polypropylene were observed upon increasing the polymerization temperature in the case of zirconocenes (5b and 6b). The effect of a 2-Me substituent at the indenyl ring on propylene polymerization was apparent in terms of polymerization activity and molecular weight of polypropylene, especially for zirconocenes, but was minor for titanocenes.Financial support from the Korea
Science and Engineering Foundation (R02-2002-000-
00057-0) is gratefully acknowledged
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