Quantitative analysis with electron energy-loss: spectroscopic imaging and its application in pathology

After the invention of the transmission electron microscope (TEM) in 1931 by Ruska and Knoll, it took about 20 years to develop the inslmment into a tool for ultrastructural research. In material science this led to the ability to visualize and investigate atomic arrangements through the imaging of columns of atoms in a lattice or by electron diffraction. In biology the instrument enabled the visualization of cell structures at an unsurpassed level of detail. New cell structures, cells and organisms were depicted and more knowledge was gained about the complex ultrastructural morphology of the cell. Novel preparation procedures for fixation, cytochemical staining and labelling, embedding and the llse of ultramicrotomy and cryo-techniques increased the investigative capabilities of the TEM in the direction of cell functioning. In physics, right from the beginning, it was recognized that the interaction of electrons irradiating a specimen can be used not only for visualization but also gives the opportunity to investigate the chemical nature of the irradiated matter. This opened the way to the analytical use of the TEM and many instruments were subsequently equipped with highly specialized detectors for each of the analytical possibilities. In this way true microanalytical laboratories were created. Two main types of TEMs have been developed: the scanning transmission electron microscope (STEM) and the conventional transmission electron microscope (CTEM)

New developments and applications in quantitative electron spectroscopic imaging of iron in human liver biopsies

Reliable iron concentration data can be obtained by quantitative analyses of image sequences, acquired by electron spectroscopic imaging. A number of requirements are formulated for the successful application of this recently developed in situ quantitative type of analysis. A demonstration of the procedures is given. By application of the technique it is established that there are no significant differences in the average iron loading of structures analysed in liver parenchymal cells of a patient with an iron storage disease, before and after phlebotomy. This supports the hypothesis that the process of iron unloading is an organelle specific process. Measurement of the binary morphology, represented by the area and contour ratio of the iron containing objects revealed no information about differences between the objects. This finding contradicts the visual suggestion that ferritin clusters are more irregularly shaped than the other iron objects. Also, no differences could be found in this sense between the situations before and after phlebotomy. With respect to the density appearance, objects that have an inhomogeneous iron loading averagely contain more iron. This observation does correspond well with the visual impression of the increasingly irregular appearance of more well-loaded structures

A predictive Methodology to Estimate the Effectiveness of Target Simulation Mode Minesweeping Operations

The Royal Norwegian Navy (RNON) and the Royal Netherlands Navy (RNLN) are both in the process of acquiring new mine sweeping systems which are capable of operating in traditional Mine Setting Mode (MSM), but are also capable of operating in Target Simulation Mode (TSM). TSM sweeping is a new philosophy. Although target simulation sweeping is in the vocabulary of many navies, there is still no agreed method of predicting the effectiveness of such an operation. TNO-FEL and FFI have been tasked by their navies to develop a tool for calculating the effectiveness when operating in TSM. To make the work more efficient, TNO-FEL and FFI have joined in a programme called SWEEPOP, with the aim of developing a measure of effectiveness in TSM operation. This MOE does not calculate the swept path as in MSM operation, but instead gives the amount of risk reduction that is achieved when TSM operation is conducted in advance of a target ship passing a minefield. This combined paper focuses on the methodology of the proposed MOE and specific research done on the acoustic propagation modellin

The probability of a random straight line in two and three dimensions

Using properties of shift- and rotation-invariance probability density distributions are derived for random straight lines in normal representation. It is found that in two-dimensional space the distribution of normal coordinates (r, phi) is uniform: p(r, phi) = c, where c is a normalisation constant. In three dimensions the distribution is given by: p (r, phi, thèta, ksi) = cr sin thèta