[en] The application of X-ray microanalysis to the study of histochemical staining reactions is reviewed. Advantages of the technique are the ability to examine colourless intermediate reaction products, and to study the efficiency of their conversion to the final reaction product. The number of X-rays emitted by an element is, under appropriate conditions, proportional to the amount of that element. Errors such as glare and deviations from Beer's Law in microdensitometry and quenching of fluorescence in microfluorimetry, are avoided. The possibility of analysing several elements simultaneously is a further advantage, as the amount of reaction product can be related to the quantity of some other cellular constituent. The application of X-ray microanalysis to the study of the binding of the fluorochrome quinacrine to nuclei is described. The extinction of this fluorochrome is too low for it to be measured by microdensitometry. X-ray microanalysis shows that its fluorescence is not proportional to the amount of quinacrine bound, and thus fluorescence cannot be used for this study. Quinacrine was shown to be strongly bound to nuclei, and the strength of its affinity is consistent with intercalative binding

[en] Most low-energy nuclear accelerators are now partly used on analytical studies in support of sciences other than nuclear physics. This paper gives a short review of such analytical techniques (X-ray analysis, elastic scattering analysis, nuclear reaction analysis, and the nuclear microprobe) with particular reference to biological applications and also emphasizes the role of the positional analysis that can be performed with a focused beam of ions - the nuclear microprobe. (author)

[en] Preliminary experiments aimed at establishing the validity of applying phi (rho z) curves to the analysis of elements from carbon to calcium in frozen-hydrated bulk biological specimens are described. Computer generated phi (rho z) curves permit simultaneous absorption and atomic number corrections to be made for quantitative analysis. The results so far obtained, whilst not conclusive, indicate that the method is valid for frozen-hydrated samples. The method allows non-ideal standards of inorganic salts to be used for quantitative light element analysis. Simultaneous oxygen analysis at 15kV with a windowless detector is possible using ice as a standard. With further refinements in spectrum processing, carbon analysis may also be possible using pure carbon as a standard. phi (rho z) curves are used to predict that absorption of x-rays from elements P to Ca will be low and that topographic changes in the specimen surface will have little effect on analyses, particularly with detectors using high take-off angles. Line-scan analyses support this prediction and in addition show that analyses of carbon and oxygen are strongly influenced by topography. The depth resolution of analysis is also predicted by phi (rho z) curves. For elements Na to Ca resolution at 15kV is approximately 2.0 micron and 1.0 micron at 10kV. These predictions are supported by experiments on frozen-hydrated sections. phi (rho z) curve analysis indicates that Na x-rays will be strongly absorbed in a frozen-hydrated specimen. It is shown experimentally that with a windowless detector the practical limit of Na detection in a frozen-hydrated bulk sample is between 10 and 25mM per kg wet wt at 15kV

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[en] Among many methods based on induction and analysis of characteristic X-ray scintillation process is the cheapest and the most simple one. It is suitable for the determination of coating thickness and composition of ores and alloys. Developing an up-to-date, universal, portable, high level instrument was decided in the Nuclear Research Institute of the Hungarian Academy of Sciences. The designed analyzer will contain, besides the usual units, a pair of differential filters and a sample changer. The accuracy will be 0,02-2%. (V.N.)

[en] New developments observed these last years in the technology of Energy Dispersive X-ray Emission Spectrometry (EDXES) instruments and in their applications to the analysis of industrial products, justify a comparison with other methods of analysis. Among these methods Wavelength Dispersive X-ray Emission Spectrometry (=WDXES) is in direct concurrence with EDXES. Activation Analysis by means of ²⁵²Cf sources has an increasing number of applications and offers particular advantages. Methods involving the use of a heavy equipment, such as Proton Induced X-ray Emission Analysis (=PIXEA), Proton Elastic Scattering Analysis (PESA), Activation or prompt γ-ray emission induced by γ rays or by heavy particles, represent relatively new developed tools available for investigation of industrial problems. (author)

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[en] A brief description of the nuclear microprobe is given. The characteristics and performances of the device are presented together with some applications to biology and metallurgy

[en] It is a well-known fact for all biological systems that, in addition to the bulk nutrients, very small amounts of certain compounds and elements are essential for the proper development and well-being of the organism. The group of compounds known as the vitamins is, of course, a well-known example of this. In contrast to the vitamins, which are almost exclusively organic in nature, certain inorganic elements in 'trace' quantities have also been shown to be essential for well-being, although in many cases it is not known exactly how they function. Unfortunately, not all such trace elements play a beneficial role; indeed, small quantities of some elements can cause serious damage to both animals and plants. (authors)