Fabrication of a pencil-shaped fiber probe with a nanometric protrusion from a metal film for near-field optical microscopy.

We propose a method to fabricate a probe with a nanometric protrusion for near-field optical microscopy. The method involves tapering process based on selective etching of an GeO2 doped fiber in buffered hydrogen fluoride solution and metallizing process by vacuum evaporation and chemical polishing. We obtained the tapered probe having a protrusion emerged from a metal film. The protrusion has an apex diameter less than 10nm and a foot diameter less than 20nm. Employing the probe, we succeeded in obtaining a highly spatially resolved image of 20nm sized gold particles.

Deducing structural variations of the apex of probes used in near-field optical microscopy through simultaneous measurement of shear force and evanescent intensity.

We propose a simple method employing the simultaneous detection of evanescent intensity and shear force to deduce variations in the near-field optical morphology of the apex of the probes used in near-field microscopy. Fabrication of our probes involves sharpening by chemical etching, metal coating, and removal of metal from the apex. We show that through the simultaneous measurement of shear force and evanescent intensity, it is possible to detect variations in the optical morphology of the very apex of the probes during near-field imaging by a scanning near-field optical microscope.

Lipid peroxidation, antioxidant defences and red-cell membrane changes in relation to coronary risk index and symptomatic coronary heart disease.

OBJECTIVE: To establish the normal lipoprotein profile in the population and identify the early warning signs of coronary heart disease (CHD). DESIGN: Random blood sampling of healthy adults and patients with symptomatic CHD including that complicated with acute myocardial infarction. METHODS: Plasma lipids, lipoproteins, lipid peroxidation, antioxidant enzymes and scavengers, red-cell membrane lipids and glycoproteins were assayed. RESULTS AND CONCLUSION: The normal levels of plasma lipids and lipoproteins were established. Levels of plasma free fatty acids, fibrinogen, white blood cell counts, echinocytes, red-cell membrane lipids and protein-bound carbohydrate components are significantly higher in healthy subjects with coronary risk index above 4.5 than they are in normal individuals. Antioxidant defences appear to be the distinguishing factor, remaining higher in normal individuals and thus keeping lipid peroxidation under control. In symptomatic CHD, antioxidant defences are significantly lowered.