Doping poly[2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylenevinylene] with PbSe nanoparticles or fullerenes.

The positions of the molecular orbitals of the conjugated semiconducting polymer, poly[2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV), relative to the Fermi level, shift when lead selenide (PbSe) quantum dots or the fullerene based molecule [(6)]-1-(3-(methoxycarbonyl)propyl)-[(5)]-1-phenyl-[5,6]-C61, known as PCBM, are dispersed in the polymer host. This is evident from the consistent shifts of occupied molecular orbitals and the valence band edge to greater binding energies and a decrease in density of states near the Fermi level, as probed by photoemission. In the case of PbSe nanocrystal quantum dots, far smaller binding energy shifts were observed. This behavior seems more characteristic of a charge donor, though PbSe and PCBM should act as charge acceptors. In the case of both dopants, what doping does exist occurs only with small concentrations (<10%). MEH-PPV doped with a large-Z semiconducting material, such as PbSe nanocrystal quantum dots, is a candidate for use as a good gamma radiation detector.

Surgery in collective protection against chemical warfare.

In the 3 months from October 1990 to January 1991, 110 operations were performed at 33 Field Hospital, Royal Army Medical Corps at Al Jubayl, Saudi Arabia in collective protection against chemical warfare. The evolution of improvements in this environment is presented in the context of the first operative series undertaken.

Nebulised salbutamol with and without ipratropium bromide in acute airflow obstruction.

103 patients with acute airflow obstruction (56 asthma, 47 chronic obstructive pulmonary disease [COPD]) completed a double-blind trial of nebulised bronchodilator treatment in a hospital accident and emergency department. Each patient was randomised to receive either 10 mg of salbutamol nebuliser solution in 2 ml of saline or 10 mg of salbutamol in 2 ml (0.5 mg) of preservative-free ipratropium bromide. Peak flow rate (PFR) was recorded before treatment and 1 hour after beginning nebulised treatment. In 23 asthmatic patients given salbutamol alone PFR rose by a mean 31% 1 hour after treatment whereas in 33 such patients given combined treatment it rose by a mean 77% (95% confidence interval for the difference 8-84%). Patients whose PFR was below 140 l/min at entry gained maximum benefit from the combined treatment. For COPD patients the PFR rise was almost identical for both treatments. In acute asthma the immediate PFR response to a mixture of salbutamol and ipratropium bromide was better than the response to nebulised salbutamol alone. For COPD patients, the two treatments were of equal benefit.

Cutaneous mucormycosis: a rare cause of leg ulceration.

Cutaneous mucormycosis followed trivial injury to the leg of a 72-year-old man. The lesion progressed rapidly requiring above-knee amputation.