Method-MS, final report 2010

Radiometric determination methods, such as alpha spectrometry require long counting times when low activities are to be determined. Mass spectrometric techniques as Inductively Coupled Plasma Mass Spectrometry (ICP-MS), Thermal Ionisation Mass Spectrometry (TIMS) and Accelerator Mass Spectrometry (AMS) have shown several advantages compared to traditional methods when measuring long-lived radionuclides. Mass spectrometric methods for determination of very low concentrations of elemental isotopes, and thereby isotopic ratios, have been developed using a variety of ion sources. Although primarily applied to the determination of the lighter stable element isotopes and radioactive isotopes in geological studies, the techniques can equally well be applied to the measurement of activity concentrations of long-lived low-level radionuclides in various samples using “isotope dilution” methods such as those applied in inductively coupled plasma mass spectrometry (ICP-MS). Due to the low specific activity of long-lived radionuclides, many of these are more conveniently detected using mass spectrometric techniques. Mass spectrometry also enables the individual determination of Pu-239 and Pu-240, which cannot be obtained by alpha spectrometry. Inductively Coupled Plasma Mass Spectrometry (ICP-MS) are rapidly growing techniques for the ultra-trace analytical determination of stable and long-lived isotopes and have a wide potential within environmental science, including ecosystem tracers and radio ecological studies. Such instrumentation, of course needs good radiochemical separation, to give best performance. The objectives of the project is to identify current needs and problems within low-level determination of long-lived radioisotopes by ICP-MS, to perform intercalibration and development and improvement of ICP-MS methods for the measurement of radionuclides and isotope ratios and to develop new methods based on modified separation chemistry applied to new auxiliary equipment

Caloric Restriction Suppresses Microglial Activation and Prevents Neuroapoptosis Following Cortical Injury in Rats

Traumatic brain injury (TBI) is a widespread cause of death and a major source of adult disability. Subsequent pathological events occurring in the brain after TBI, referred to as secondary injury, continue to damage surrounding tissue resulting in substantial neuronal loss. One of the hallmarks of the secondary injury process is microglial activation resulting in increased cytokine production. Notwithstanding that recent studies demonstrated that caloric restriction (CR) lasting several months prior to an acute TBI exhibits neuroprotective properties, understanding how exactly CR influences secondary injury is still unclear. The goal of the present study was to examine whether CR (50% of daily food intake for 3 months) alleviates the effects of secondary injury on neuronal loss following cortical stab injury (CSI). To this end, we examined the effects of CR on the microglial activation, tumor necrosis factor-α (TNF-α) and caspase-3 expression in the ipsilateral (injured) cortex of the adult rats during the recovery period (from 2 to 28 days) after injury. Our results demonstrate that CR prior to CSI suppresses microglial activation, induction of TNF-α and caspase-3, as well as neurodegeneration following injury. These results indicate that CR strongly attenuates the effects of secondary injury, thus suggesting that CR may increase the successful outcome following TBI

Propofol-Induced Changes in Neurotrophic Signaling in the Developing Nervous System In Vivo

Several studies have revealed a role for neurotrophins in anesthesia-induced neurotoxicity in the developing brain. In this study we monitored the spatial and temporal expression of neurotrophic signaling molecules in the brain of 14-day-old (PND14) Wistar rats after the application of a single propofol dose (25 mg/kg i.p). The structures of interest were the cortex and thalamus as the primary areas of anesthetic actions. Changes of the protein levels of the brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF), their activated receptors tropomyosin-related kinase (TrkA and TrkB) and downstream kinases Akt and the extracellular signal regulated kinase (ERK) were assessed by Western immunoblot analysis at different time points during the first 24 h after the treatment, as well as the expression of cleaved caspase-3 fragment. Fluoro-Jade B staining was used to follow the appearance of degenerating neurons. The obtained results show that the treatment caused marked alterations in levels of the examined neurotrophins, their receptors and downstream effector kinases. However, these changes were not associated with increased neurodegeneration in either the cortex or the thalamus. These results indicate that in the brain of PND14 rats, the interaction between Akt/ERK signaling might be one of important part of endogenous defense mechanisms, which the developing brain utilizes to protect itself from potential anesthesia-induced damage. Elucidation of the underlying molecular mechanisms will improve our understanding of the age-dependent component of anesthesia-induced neurotoxicity

Public opinion on healthcare in the context of economic crisis: evidence from Portugal

This article investigates to what extent austerity-oriented measures introduced in the Portuguese health sector during the recent economic crisis were associated with changes in the public opinion on healthcare. We conducted multivariate regression analyses of cross-sectional, biannual data from the European Social Survey (2002–2015) for 13,271 individuals living in private households in Portugal. In line with our expectations, healthcare evaluations of the general population improved until 2010 but declined with the implementation of comprehensive austerity measures introduced under the Memorandum of Understanding after 2011. Healthcare evaluations of vulnerable social groups – older and retired individuals, individuals with poor health, low income and education – declined particularly strongly. In addition, differences in healthcare evaluations between more and less vulnerable social groups were more pronounced after 2011. Interestingly, healthcare evaluations of the general population and of some of the most vulnerable groups ‘recovered’ in 2015, when most of the Memorandum measures were implemented. Our findings contribute to the literature on the effects of austerity measures on welfare attitudes and stress the need to analyse the differential impact of crisis-induced welfare state reforms across social groups.The authors would like to thank the editors of the Journal of Social Policy and the anonymous reviewers for their valuable comments on earlier drafts of this manuscript. For all statements of fact, data analyses and interpretation of results, the authors alone bear responsibility. This research is part of the NORFACE Welfare State Futures funded research project ‘The Paradox of Health State Futures’ (HEALTHDOX) (EC ERA-Net Plus funding, grant agreement number 618106, file number 462-14-070)

Anomalous dissolution of metals and chemical corrosion

An overview is given of the anomalous behavior of some metals, in particular Fe and Cr, in acidic aqueous solutions during anodic dissolution. The anomaly is recognizable by the fact that during anodic dissolutionmore material dissolves than would be expected from the Faraday law with the use of the expected valence of the formed ions. Mechanical disintegration, gas bubble blocking, hydrogen embrittlement, passive layer cracking and other possible reasons for such behavior have been discussed. It was shown, as suggested by Kolotyrkin and coworkers, that the reason can be, also, the chemical reaction in which H2O molecules with the metal form metal ions and gaseous H2 in a potential independent process. It occurs simultaneously with the electrochemical corrosion process, but the electrochemical process controls the corrosion potential. On the example of Cr in acid solution itwas shown that the reason for the anomalous behavior is dominantly chemical dissolution, which is considerably faster than the electrochemical corrosion, and that the increasing temperature favors chemical reaction, while the other possible reasons for the anomalous behavior are of negligible effect. This effect is much smaller in the case of Fe, but exists. The possible role of the chemical dissolution reacton and hydrogen evolution during pitting of steels and Al and stress corrosion cracking or corrosion fatigue are discussed

Dissolution of chromium in sulfuric acid

By combining electrochemical corrosion rate measurements and spectrophotometric analysis of the electrolyte it was shown that at room temperature chromium dissolves in deaerated 0.1 M Na2SO4 + H2SO4 (pH 1) solution as Cr(II) and Cr(III) ions in he ratio Cr(II) : Cr(III) @ 7 : 1. This process was stable over 4 h without any detectable change. The total corrosion rate of chromium calculated from the analytical data is about 12 times higher, than that determined electrochemically by cathodic Tafel line extrapolation to the corrosion potential. This finding was confirmed by applying the weight-loss method for the determination of the corrosion rate. This enormous difference between these experimentally determined corrosion rates can be explained by the rather fast, anomalous dissolution process proposed by Kolotyrkin and coworkers (chemical reaction of Cr with H2O molecules) occurring simultaneously with the electrochemical corrosion process

Phosphorus fertilizers as a source of uranium in Serbian soils

Around 1500 t of mineral fertilizers based on phosphorus are applied per annum in Serbia. It is estimated that around 210 kg of uranium (30 g/ha) are in this way introduced into the environment. Due to this fact there is a risk of exposing local population to ionizing radiation. The purpose of this article was to determine whether long-term application of phosphorus fertilizers causes increase of uranium content in arable soils. These investigations were made using field experiments that were set up on three types of soil, chernozem, smonitza and pseudogley, more than 30 years ago. Same variants of mineral nutrition were used in these experiments and all fields had parcels without application of fertilizers (controls). Soil samples were taken from two soil layers (0–30 cm and 30–60 cm) continuously in a period of five years. Statistical analysis of the results obtained indicates that significant differences exist between the control and application of phosphorus fertilizers in the layer from 0–30 cm, while no such differences were found for the layer from 30–60 cm. Physicochemical soil properties change the process of uranium migration and mobilization. Indeed the fixation of uranium by investigated soil types decreases in the following order: chernozem>smonitza>>pseudogley. Since the natural content of uranium in Serbian soils is in the interval from 0.08 to 5.9 ppm, it can be concluded that the results obtained in this investigation are within natural limits. Indeed, the values obtained for total uranium content in the investigated experimental variants were in the range from 0.65 to 1.94 ppm. This finding is of great value from the aspect of environmental protection and prevention of uranium of anthropogenic origin to be incorporated in food chain

Structural effects of metallic chromium on its electrochemical behavior

Chromium dissolution in aqueous sulfuric acid solution of pH 1 was studied electrochemically on chromium electrodes with different crystallographic structures. A slow potentiodynamic method was used for the electrochemical measurements in deaerated solutions (purgedwith nitrogen),while the Cr(III) ions in the solution after the corrosion were determined by atomic absorption spectrometry. Three electrode materials with a very dominant crystallite orientation resembling single crystal structures (i.e., 111 and 110) confirmed by the electron backscattering diffraction (EBSD), were used in the experiments. The (111) structures were somewhat more active electrochemically (both anodic and cathodic) than the (110) structure. However, Cr electrochemically deposited in standard plating bath, assumed from literature data to has also the (111) structure, was more than 4 times active for anodic dissolution and, by the same number, less active for cathodic hydrogen evolution. The concentrations of Cr(III) ions determined in the solution after definite times of corrosion of all the materials showed almost two times larger dissolution rates than observed electrochemically by three different electrochemical methods (Wagner–Traud, Stern–Geary, electrochemical impedance spectroscopy). This is explained by the simultaneous occurrence of potential independent chemical dissolution of Cr, by a direct reaction of metallic Cr with H2O molecules, proposed a long time ago by Kolotyrkin and coworkers