Self-assembly of high-nuclearity metal clusters: programmed expansion of a metallasiloxane cage to an octacopper(II) cluster.

The novel octanuclear copper(II) cluster [Cu6[(PhSiO2)6]2[NCCu(Me6tren)]2(MeOH)4]2+ (1) has been isolated as a perchlorate salt by reacting the hexacopper(II) metallasiloxane cage [Cu6[(PhSiO2)6]2(nBuOH)x] (x = 4, 6) with [Cu(Me6tren)CN]ClO4 in a methanol/chloroform mixture (Me6tren = tris(2-(dimethylamino)ethyl) amine). Crystal data for 1(ClO4)2 x MeOH: monoclinic, space group P2(1)/n (no. 14), a = 16.

Structure and Magnetic Properties of a Mixed-Valence Heptanuclear Manganese Cluster.

Two novel polynuclear manganese(II,III) complexes have been synthesized by exploiting controlled methanolysis. A one-pot reaction of MnCl(2), NaOMe, dibenzoylmethane (Hdbm), and O(2) in anhydrous methanol, followed by recrystallization from MeOH/CHCl(3) mixtures, afforded the alkoxomanganese complexes [Mn(7)(OMe)(12)(dbm)(6)].CHCl(3).

Single-ion versus dipolar origin of the magnetic anisotropy in iron(III)-oxo clusters: a case study.

A multitechnique approach has allowed the first experimental determination of single-ion anisotropies in a large iron(III)-oxo cluster, namely [NaFe6(OCH3)12(pmdbm)6ClO4 (1) in which Hpmdbm = 1,3-bis(4-methoxyphenyl)-1,3-propanedione. High-frequency EPR (HF-EPR). bulk susceptibility measurements, and high-field cantilever torque magnetometry (HF-CTM) have been applied to iron-doped samples of an isomorphous hexagallium(III) cluster [NaGa6(OCH3)12-(pmdbm)6]ClO4, whose synthesis and X-ray structure are also presented.

Tuning of Magnetic Anisotropy in Hexairon(III) Rings by Host-Guest Interactions: An Investigation by High-Field Torque Magnetometry.

Full chemical control of magnetic anisotropy in hexairon(III) rings can be achieved by varying the size of the guest alkali metal ion. Dramatically different anisotropies characterize the Li(I) and Na(I) complexes of [Fe(6)(OMe)(12)(L)(6)] (L=1,3-propanedione derivatives; a schematic representation of the Li(I) complex is shown), as revealed by high-field torque magnetometry-Iron: (g), oxygen: o, carbon: o, Li(+): plus sign in circle.

Does the measurement of portal flow velocity have any value in the identification of patients with cirrhosis at risk of digestive bleeding?

Upper gastrointestinal bleeding is a leading cause of death in patients with liver cirrhosis. In most cases haemorrhage originates from oesophageal varices or from congestive gastropathy, and the evaluation of the bleeding risk is based on oesophagogastroduodenoscopic data. The aim of this prospective study was to determine whether the measurement of portal flow velocity by Duplex-Doppler, compared with endoscopic data, can help in detecting patients with cirrhosis at risk of bleeding.

[Roxatidine in the treatment of gastroduodenal mucosal lesions in hepatic cirrhosis].

In about 50% of patients with liver cirrhosis, upper digestive bleeding is not due to oesaphageal varices rupture, but to a group of peculiar mucosal lesions usually referred as "congestive gastropathy" and "hepatogenic ulcer". The pathogenesis of such mucosal damage is still unclear: an important causative role is commonly thought to be played by portal hypertension, but the role of peptical pathway and of the mucosal barrier impairment must not be underscored as well. Aim of this study was to evaluate the effect of roxatidine in the long-term treatment of mucosal damage in 19 patients with liver cirrhosis.