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This work describes the basic principles of Total-reflection X-Ray Fluorescence (TXRF) spectrometry and some of its most outstanding applications for investigating metal traces, mainly in biological and biomedical samples. TXRF is an analytical technique that combines the versatility of elemental analysis by X-ray energy dispersion with a low detection limit in the order of picograms of absolute mass or a few ppb (μg L−1) as concentration. The microanalytical capacity of TXRF allows the study of small sample quantities. The TXRF can perform qualitative and mass ratio analyses of the elements present in a sample of only a few hundred nanograms. These properties are of great importance in the research of metal traces in biological systems, as they allow fast, precise, and accurate characterisation of the elemental fingerprint at trace level. Its successful application in studies of the coordination kinetics of new platinum-based antitumor drugs with DNA, its application in the study profile of the metal in healthy and cancerous human tissues, or even its application in the study of the processes of metal diffusion through cell membranes are just a few examples of TXRF capabilities in the biomedical sciences. This brief review's main objective is to provide an overview of the physical principles and possibilities of TXRF spectrometry. It also highlights some of the most outstanding applications that have been developed so far, mainly in the biological field, so that the reader can evaluate their potential applications.  相似文献   
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Russian Physics Journal - Aiming at problems of low probability of interception and poor anti-jamming performance of the multi-output radar, the numerical simulation based on a chaos optimization...  相似文献   
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Fuzzy Optimization and Decision Making - Cost-allocation problems in a fixed network are concerned with distributing the costs for use by a group of clients who cooperate in order to reduce such...  相似文献   
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Organisations are concerned about measuring the performance of the product/service they deliver to their customers. In all types of organisations, if a proper performance assessment is to be developed, it should be measured in different dimensions. At University, the new study programs include the development and assessment of transversal competences due to their importance in enhancing the abilities and improving the employability of students. The achievement of transversal competences can be assessed in different levels/stages; for example, the 1st and 2nd years of a Bachelor’s degree; the 3rd and 4th years of a Bachelor’s degree and at Master’s level. The purpose of this paper is to integrate the research into performance management in organisations to develop an approach consisting of four components (a methodology, a solid and integrated performance management framework, graphical diagrams and quantitative techniques) to assess and manage the achievement of transversal competences through the different levels of study using a consolidated approach. The proposal uses the Analytic Network Process (ANP) to model dependences and feedback among the elements of the competences.

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Central European Journal of Operations Research - Sustainability practice within supply chains remains in an early development phase. Enterprises still need tools that support the integration of...  相似文献   
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Experimental Techniques - In the last years, the wind industry has increased in a large scale. A wind turbine out of service leeds to high costs due to both maintenance and repair costs and the...  相似文献   
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Algebras and Representation Theory - Let A and B be two Morita equivalent finite dimensional associative algebras over a field ��. It is well known that Hochschild cohomology is...  相似文献   
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Advances in Data Analysis and Classification - Symbolic Data Analysis (SDA) is a relatively new field of statistics that extends conventional data analysis by taking into account intrinsic data...  相似文献   
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Mathematical Programming - Let G be a digraph where every node has preferences over its incoming edges. The preferences of a node extend naturally to preferences over branchings, i.e., directed...  相似文献   
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