Image acquisition with immersion objective lenses using electrons emitted with several tenths of an electron volt energies: towards high spatial resolution ESCA analysis.

This study aims to evaluate the spatial resolution achievable with photoelectrons in order to perform localised UPS or XPS analyses on various heterogeneous samples. This investigation is intentionally restricted to direct image acquisition by immersion objective lenses, involving electrons ejected with initial energies of several tenths of an electron-volt. In order to characterise the contribution of all optical elements, analytical investigations were associated to numerical simulations based on SIMION 7 software. The acquisition of high-quality images implies a simultaneous reduction in spherical and chromatic aberrations by a narrow aperture stop placed at the output pupil of the objective. With such limitations in useful emission angles, it is shown that monochromatic electron beams build images with a resolution of about 1 nm, especially for the acceleration bias mode where the focussing electrode is biased at a positive high voltage. Even energy dispersed electron beams, limited by a 4 eV band pass spectrometer, can produce images convenient for highly localised ESCA analyses (resolution 3 nm), where the objective lens is associated with an aperture stop of 30 microm in diameter without using acceleration voltages above 5000 V.

Transmyocardial laser revascularization.

In transmyocardial laser revascularization, a small left thoracotomy incision is made at the fifth rib. The surgeon dissects until adequate exposure of the heart is made, and the laser can be used. The areas to be lasered are identified, and treatment begins. As each laser beam penetrates the myocardium, a flash of bubbles can be seen on echocardiogram exiting the left ventricular outflow tract, which confirms adequate channeling. After revascularization, the mitral valve is inspected for any damage to papillary muscle or leaflets. This case report focuses on a new laser procedure that creates channels in the heart that promote angiogenesis and reestablish blood flow. A 47-year-old man presented for this surgery after having previous coronary artery bypass surgery. He had worsening angina and was not recommended for repeat bypass surgery because of his diffuse disease. Transmyocardial laser revascularization was offered as an alternative to medical therapy. Complications reported include dysrhythmia, bleeding, congestive heart failure, mitral valve damage, low cardiac output syndrome, and death. Many patients note substantial anginal relief after a few weeks. Transmyocardial laser revascularization gives an alternative to those with intractable angina and generally offers an improvement in quality of life.