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

Regulatory control of naturally occurring radioactive material (NORM) in the Nordic countries : Report from working group Nordic NAT

Radiological risks associated with naturally occurring radioactive materials (NORM) have been fully recognized in recent decades, and hence, resulted in the integration of NORM radiation protection requirements within the EU Directive 2013/59 and IAEA BSS (2014). Still, it has been internationally emphasized that NORM-related knowledge gaps and uncertainties might present issues in coping with the existing regulatory requirements during their transposition and implementation into national legislations and regulatory frameworks. Therefore, NORM is one of the main subjects in the recently formed Nordic working group on natural ionizing radiation (WG Nordic[1]Nat). NORM regulatory approaches for radiation protection control, possibilities for collaboration, scientific projects and joint research, monitoring programmes, communication issues, etc. are considered within the group, based on the defined mandate. The current report is a result of the first joint WG Nordic-Nat activity related to NORM, and it provides an overview of national legislations, regulatory approaches and practices concerning NORM across Nordic countries i.e., Denmark, Finland, Iceland, Norway and Sweden. Denmark, Finland and Sweden are member states of the European Union (EU), and hence, the Council Directive 2013/59/Euratom (EU BSS) containing NORM specific requirements has been adopted and implemented in the legislation of these countries. Although Norway and Iceland are not member states of the EU, and thus not bound by the EU BSS, legislation and regulatory approaches for NORM have also been developed in these countries according to the international standards and specific country circumstances. Both differences and similarities related to the legislation, adopted regulatory control approaches for handling of NORM in the industries, NORM waste management and disposal as well as for environmental discharge control have been seen across Nordic countries, and are presented in this report. Furthermore, a provided description of the approahes in regulatory control of NORM-processing industries, NORM waste and pollution in the Nordic countries allows an identification of the common interest for NORM specific issues. The potential topics for future WG Nordic-Nat collaboration have been identified as (a) use of dose criteria for exemption and clearance of NORM and NORM industries from notification and authorization; (b) safety and environmental assessments for radioactive NORM waste disposal and discharge; (c) regulatory control of multi[1]contaminants in NORM waste; (d) environmental monitoring in NORM processing industries and disposal sites; (e) inspections in facilities involving NORM; (f) NORM legacy sites and remediation; (g) stakeholder engagement and risk communication in NORM; (h) transboundary movement of NORM waste for disposal and NORM contaminated materials for processing, and finally, (i) potential update of Nordic flag book - publication “Naturally Occurring Radiation in the Nordic Countries (Recommendations, 2000)

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

Translational control of depression-like behavior via phosphorylation of eukaryotic translation initiation factor 4E

Translation of mRNA into protein has a fundamental role in neurodevelopment, plasticity, and memory formation; however, its contribution in the pathophysiology of depressive disorders is not fully understood. We investigated the involvement of MNK1/2 (MAPK-interacting serine/threonine-protein kinase 1 and 2) and their target, eIF4E (eukaryotic initiation factor 4E), in depression-like behavior in mice. Mice carrying a mutation in eIF4E for the MNK1/2 phosphorylation site (Ser209Ala, Eif4e ki/ki), the Mnk1/2 double knockout mice (Mnk1/2 -/-), or mice treated with the MNK1/2 inhibitor, cercosporamide, displayed anxiety-and depression-like behaviors, impaired serotonin-induced excitatory synaptic activity in the prefrontal cortex, and diminished firing of the dorsal raphe neurons. In Eif4e ki/ki mice, brain IκBα, was decreased, while the NF-κB target, TNFα was elevated. TNFα inhibition in Eif4e ki/ki mice rescued, whereas TNFα administration to wild-type mice mimicked the depression-like behaviors and 5-HT synaptic deficits. We conclude that eIF4E phosphorylation modulates depression-like behavior through regulation of inflammatory responses

Miljøkonsekvenser knyttet til radionuklider og sporelementer i det thoriumrike Fensfeltet i Norge

The Fen Complex which is situated in the south of Norway, represents a magmatic bedrock area enriched in thorium (Th), iron (Fe), niobium (Nb) and rare earth elements (REE), and is well known for the elevated levels of natural ionizing radiation. This area has been of public interest from the 17th century when Fe mining started in the central wooded zone of the Fen Complex. Intensive mining of Fe continued until the 20th century, while mining and the production of ferro-niobium were conducted at the site Søve in the western part of the Complex in 1950s. Recently, intensive focus has been directed to the estimated large quantities of Th and REE ores, their value and possibility for future use, but also to environmental issues linked to the legacy enhanced naturally occurring radioactive materials (NORM) in the area. Many studies investigating different aspects of specific bedrock geology, as well as human health risk related to elevated ionizing radiation levels in the area, have been published. Still, no comprehensive investigation of different environmental compartments and radionuclides impact on biota at both legacy enhanced and undisturbed NORM sites in the Fen Complex has been undertaken. The present work was initiated as an integrated ecological and human impact assessment whose main objectives were to assess the possible radionuclide and trace elements contamination of the Fen Complex environment, impact on biota and radiation doses to humans due to outdoor radiation exposure. The Fen Complex area which is comprised of both legacy NORM and undisturbed 232Th-rich sites served as a natural laboratory where environmental compartments and biota could be investigated in the natural state, under realistic conditions. With respect to the specific Fen area and previously published data, the main focus of this work was on radionuclides such as 232Th and uranium (238U) and their progenies, as well on trace elements such as arsenic (As), chromium (Cr), cadmium (Cd) and lead (Pb). The generated data provided information on the current environmental status at both undisturbed and legacy NORM sites in the area, and could be used in planning of eventual remediation activities or for future monitoring. To assess the impact of radionuclides and trace elements on the ecosystem and humans, information was needed regarding the characterization, mobility and biological uptake of radionuclides and trace elements, as well as their different exposure pathways. These aspects were studied and presented in five scientific papers on which this thesis is based on.Fensfeltet, lokalisert i Sør Norge, representer et magmatisk berggrunnsområde beriket med thorium (Th), jern (Fe), niob (Nb) og sjeldne jordelementer (REE). Det er velkjent for forhøyet nivå av naturlig ioniserende stråling. Fensfeltet har vært av offentlig interesse siden 1600-tallet da gruvedriften av Fe begynte i sentral skogkledd sone. Det ble drevet intensiv gruvedrift av Fe frem til 1900-tallet, mens gruvedrift og produksjon av ferro-niob ble gjennomført på 1950-tallet i Søve gruver, i den vestlige delen av komplekset. Nylig ble fokus igjen rettet mot Fensfeltet og store estimerte konsentrasjoner av Th og REE, deres verdi og muligheter for fremtidig bruk, samt mot miljøproblematikk knyttet til historiske NORM områder som eksisterer i området. Det har blitt publisert flere studier som forsket på forskjellige aspekter av spesifikk berggrunnsgeologi, samt helserisiko for mennesker relatert til forhøyede nivåer av forhøyet ioniserende stråling i område. Fortsatt har ingen omfattende forskning på forskjellige miljøaspekter og påvirkning av planter i verken tidligere gruveområder eller uforstyrrede NORM områder i Fensfeltet blitt gjennomført. Dette arbeidet ble initiert som en integrert studie for miljøvurdering. Hovedmålet var å få til risikovurdering av av Fensfeltet fra radioaktivitet og metaller blant annet ved å se på påvirkning av biota og stråledoser for mennesker gjennom utendørs eksponering. Fensfeltet, bestående av både tidligere gruveområder med NORM og uforstyrrede områder rike på 232Th, ble brukt som naturlige laboratorier hvor jord, vann, luft og biota kunne undersøkes under realistiske forhold. Basert på tidligere publiserte data og opplysninger om området, ble hovedfokus rettet mot radionuklider som 232Th, uran (238U) og deres døtre samt sporelementer som arsen (As), krom (Cr), kadmium (Cd) og bly (Pb). Genererte data ga opplysninger om nåværende miljøstatus i både uforstyrrede og historiske NORM områder. Disse dataene kan bli brukt til planlegging av eventuelle aktiviteter for utbedring og fremtidig overvåkning. For å vurdere radionukliderelatert påvirkning av økosystemet og mennesker, var det nødvendig å gjøre karakterisering av forskjellige prøver, undersøke mobilitet og biologisk opptak av radionuklider og sporelementer, samt deres eksponeringsvei og påvirkning av biota og mennesker. Disse aspektene ble studert og presentert i fem vitenskapelige artikler som denne doktoravhandlingen er basert på