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M Escher

Publications and source records attributed to M Escher.

11 recordsLinked to original sources

Use of emission electron microscope for potential mapping in semiconductor microelectronics.

An emission electron microscope was used for visualization and measurement of the distribution of electric fields and potentials on the surface under study. The contrast of microfields is caused by the fact that slow-moving electrons emitted from the object surface are deflected by these fields. The measurements were performed on a p-n junction to which a voltage was applied. It is shown that the type of contrast from the p-n junction can be reversed depending on the position of the contrast aperture restricting the electron beam. The same result was obtained by means of a computer simulation.

Journal Article↗

Primary care physicians' knowledge and attitudes towards genetic testing for breast-ovarian cancer predisposition.

BACKGROUND: Primary health care providers are expected to be directly involved in the genetic testing for cancer susceptibility. This study assessed physicians' knowledge, attitude and perception of their role towards testing for hereditary breast ovarian cancer. DESIGN: A mail-in survey was sent to all general practitioners, internists, obstetrician-gynecologists and oncologists in private practice in Geneva county, Switzerland. Questions included socio-demographic variables, knowledge about hereditary breast ovarian cancer, attitude towards testing and assessment of their role in the pre- and post-test procedure. RESULTS: Two hundred fifty-nine (65%) of four hundred questionnaires were returned of which two hundred forty-three (61%) were analysed. Response rates were similar between specialties; women answered more frequently. The majority of the respondents (87%) approved of genetic susceptibility testing. The most common objection to testing was the absence of approved strategies for the prevention and detection of early breast cancer. Most physicians felt they had an active part to play in the pre-test procedure, the disclosure of results, and especially the consultants' long-term care and support (99%). Physicians correctly answered a third (32%) of the knowledge questions. The abstention rate for individual items ranged from 13% to 60%. Scores varied by specialty. Oncologists were more knowledgeable than gynecologists, internists and general practitioners. CONCLUSIONS: The majority of the primary care physicians in this study have a favourable attitude and are ready to play a prominent role in genetic counseling and testing for breast ovarian cancer predisposition. Defective knowledge scores, however, underline the need for targeted educational programs.

Attitude of Health Personnel↗

Peculiarities of imaging one- and two-dimensional structures in an emission electron microscope. 1. theory

Local changes in work function cause deviations of the electrical microfield near a sample surface as a result of the uniform accelerating field distribution between the sample (cathode) and the extractor electrode (anode). This results in a change in the electron trajectories. As a consequence, the microscope image shows remarkable changes in position, size, intensity and lateral resolution of distinct details, which can be quantitatively described by the calculations presented here. Analysing these effects in the image gives an opportunity to determine the real lateral size of the observed structures and the distribution of local contact potentials.

Journal Article↗