Mono- and Bis-Terpyridine-Based Dimer and Metallo-Organic Polymers as Ionic Templates for Preparation of Multi-Metallic Au Nanocluster and Nanowires.

The preparation of multi-metallic Au nanocluster and nanowires has been achieved using terpyridine-based metallo-organic polymers as multi-ionic templates through a straightforward counterion exchange with aqueous NaAuCl4 followed by a mild reduction in-situ with sodium citrate. The mild reduction of the [TpyFeTpy]2+ x 2[AuCl4]- complex, derived from [TpyFeTpy]2+ x 2Cl- 1 (tpy = 2,2':6',2"-terpyridine), led to the formation of Au nanoclusters (Au NC) with diameters ranging from 7.5-88 nm. Each Au NC alone contained multiple nanoparticles, with diameters ranging from 2.5-4.5 nm. 1,4-bis-terpyridine based metallo-oraganic polymer [-TpyFeTpy-TpyFeTpy-]n(2n+) x [Cl]2n- 2 was found to generate a multi-ionic metallo-polymer with AuCl4- as the counterion, after mild reduction with sodium citrate, resulting in irregular zigzag shaped Au nanowires (Au NW). The prepared Au NW from the di-metallic complex 3 should find applications within electronic devices. Both Au NC and NW were also found to possess excellent catalytic properties.

Design and Self-Assembly of Macrocycles with Metals at the Corners Based on Dissymmetric Terpyridine Ligands.

Terpyridine-based discrete supramolecular architectures with metal ions at the corners have rarely been reported. Herein, we report two dissymmetric terpyridyl ligands LA and LB decorated at the 5-position and 4-position of terpyridine respectively. The complexes constructed by the self-assembly of LA and LB with Zn(II) exhibit hand-circle-like structures. Moreover, all Zn(II) are successfully fixed in the corners. A series of dimeric to hexameric macrocycles is obtained by head-to-tail connections with changing concentration. This work will pave the way for preparation of more elaborate self-assembled structures based on dissymetric ligands.

The current strategy of repair of tetralogy of Fallot in children and adults.

OBJECTIVES: The strategies of repair of tetralogy of Fallot change with the age of patients. In children older than 4 years and adults, the optimal strategy may be to use different method of reconstruction of the right ventricular outflow tract from those followed in younger children, so as to avoid, or reduce, the pulmonary insufficiency that is increasingly known to compromise right ventricular function. METHODS: From April, 2001, through May, 2008, we undertook complete repair in 312 patients, 180 male and 132 female, with a mean age of 11.3 years +/-0.4 years, and a range from 4 to 48 years, with typical clinical and morphological features of tetralogy of Fallot, including 42 patients with the ventriculo-arterial connection of double outlet right ventricle. The operation was performed under moderate hypothermia using blood cardioplegia. The ventricular septal defect was closed with a Dacron patch. When it was considered necessary to resect the musculature within the right ventricular outflow tract, or perform pulmonary valvotomy, we sought to preserve the function of the pulmonary valve by protecting as far as possible the native leaflets, or creating a folded monocusp of autologous pericardium. RESULTS: The repair was achieved completely through right atrium in 192, through the right ventricular outflow tract in 83, and through the right atrium, the outflow tract, and the pulmonary trunk in 36 patients. A transjunctional patch was inserted in 169 patients, non-valved in all but 9. There were no differences regarding the periods of aortic cross-clamping or cardiopulmonary bypass. Of the patients, 5 died (1.6%), with no influence noted for the transjunctional patch. Of those having a non-valved patch inserted, three-tenths had pulmonary regurgitation of various degree, while those having a valved patch had minimal pulmonary insufficiency and good right ventricular function postoperatively, this being maintained after follow-up of 8 to 24-months. CONCLUSIONS: Based on our experience, we suggest that the current strategy of repair of tetralogy of Fallot in older children and adults should be based on minimizing the insertion of transjunctional patches, this being indicated only in those with very small ventriculo-pulmonary junctions. If such a patch is necessary, then steps should be taken to preserve the function of the pulmonary valve.

Microwave measurement of giant unilamellar vesicles in aqueous solution.

A microwave technique is demonstrated to measure floating giant unilamellar vesicle (GUV) membranes in a 25 µm wide and 18.8 µm high microfluidic channel. The measurement is conducted at 2.7 and 7.9 GHz, at which a split-ring resonator (SRR) operates at odd modes. A 500 nm wide and 100 µm long SRR split gap is used to scan GUVs that are slightly larger than 25 µm in diameter. The smaller fluidic channel induces flattened GUV membrane sections, which make close contact with the SRR gap surface. The used GUVs are synthesized with POPC (16:0-18:1 PC 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine), SM (16:0 Egg Sphingomyelin) and cholesterol at different molecular compositions. It is shown that SM and POPC bilayers have different dielectric permittivity values, which also change with measurement frequencies. The obtained membrane permittivity values, e.g. 73.64-j6.13 for POPC at 2.7 GHz, are more than 10 times larger than previously reported results. The discrepancy is likely due to the measurement of dielectric polarization parallel with, other than perpendicular to, the membrane surface. POPC and SM-rich GUV surface sections are also clearly identified. Further work is needed to verify the obtained large permittivity values and enable accurate analysis of membrane composition.

Construction of CdS quantum dots via a regioselective dendritic functionalized cellulose template.

Using regioselective dendritic functionalized cellulose, CdS quantum dot nanoparticles were prepared and their photo-optical properties and morphology as well as the preliminary biocompatibility of the hybrid were investigated.

Synthesis, X-ray structure, and self-assembly of functionalized bis(2,2':6',2' '-terpyridinyl)arenes.

meta-Bis(terpyridinyl)phenol has been synthesized from O-benzyl-3,5-di(formyl)phenol in three steps. Its alkylation afforded a series of bisterpyridinylarenes, which can be self-assembled to afford the corresponding hexametallomacrocycles possessing Fe(II), Zn(II), or Ru(II) connectivity. [structure: see text]