Organic rectifying junctions from an electron-accepting molecular wire and an electron-donating phthalocyanine.

Self-assembled monolayers (SAMs) of arylene-ethynylene oligomers that incorporate electron-accepting 9-fluorenone and 9-[(4-pyridyl)methylene]fluorene units in the backbone exhibit symmetrical current–voltage (I–V) characteristics, but rectifying junctions with current ratios of 20–80 at ±1 V have been obtained by protonating these wire-like molecules and ionically coupling with anionic donors

Risk stratification scores in elective open abdominal aortic aneurysm repair: are they suitable for preoperative decision making?

Objectives<p></p> Risk indices help quantify the risk of cardiovascular events and death prior to making decisions about prophylactic AAA repair. This paper aims to study the predictive capabilities of 5 validated indices.<p></p> Design and methods<p></p> A prospective observational multi-centre cohort study from August 2005 to September 2007 in Glasgow recruited 106 consecutive patients undergoing elective open AAA repair. The Glasgow Aneurysm Score (GAS), Vascular physiology only Physiological and Operative Severity Score for enUmeration of Mortality (V(p)-POSSUM), Vascular Biochemical and Haematological Outcome Model (VBHOM), Revised Cardiac Risk Index (RCRI) and Preoperative Risk Score of the Estimation of Physiological Ability and Surgical Stress Score (PRS of E-PASS) were calculated. Indices were compared using receiver operating characteristic (ROC) analysis and area under the curve (AUC) estimates. End points were all-cause mortality, Major Adverse Cardiac Events (MACE) and cardiac death.<p></p> Results<p></p> GAS, VBHOM and RCRI did not predict outcome. V(p)-POSSUM predicted MACE (AUC = 0.681), cardiac death (AUC = 0.762) and all-cause mortality (AUC = 0.780), as did E-PASS (AUC = 0.682, 0.821, 0.703 for MACE, cardiac death and all-cause mortality respectively).<p></p> Conclusion<p></p> Whilst V(p)-POSSUM and E-PASS predicted outcome, the less complex RCRI and GAS performed poorly which questions the utility of decision making based on these surgical risk indices

Single-molecule electrical studies on a 7 nm long molecular wire.

A self-assembled arylene–ethynylene molecular wire with a rigid 7 nm long backbone exhibits symmetrical current–voltage (I–V) characteristics and a single-molecule current of 0.35 ± 0.05 nA at 0.3 V; these data are supported by theoretical calculations

Chalcogenation of tetrathiafulvalene (TTF): synthesis of alkylthio-TTF and alkylseleno-TTF derivatives and X-ray crystal structure of ethylenediseleno TTF (EDS-TTF)

The reaction of mono-lithiated tetrathiafulvalene (TTF) with elemental sulfur or elemental selenium at -78-degrees-C yields the transient species TTF-S- Li+ and TTF-Se- Li+, respectively, which have been trapped with a range of alkyl halides to yield new alkylthio- and alkylseleno-TTF derivatives. Reaction of the TTF-thiolate anion with 2-bromoethanol yields 4-(2-hydroxyethylthio)tetrathiafulvalene which is a particularly versatile building block for the synthesis of a range of new mono-functionalised TTF derivatives containing ether, ester, acrylate, urethane and vinylthio groups in the side chain. One-pot syntheses of ethylenedithio-TTF (EDT-TTF) and ethylenediseleno-TTF (EDS-TTF) from TTF are reported. The structure of EDS-TTF has been determined by single crystal X-ray analysis which reveals dimers with molecular planes orthogonal to each other

Synthesis and properties of new functionalized tetrathiafilvalene (ttf) pi-electron donors

The synthesis, solution electrochemistry, and X-ray crystal structures of a wide range of highly-functionalised TTF derivatives are presented