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Whatever the radionuclide to be used in nuclear medicine, it is essential to know the expected yield during the production process, but also of all the possible radionuclidic impurities coproduced, that can have an impact on the product final quality, as well as in the related waste management. The availability of the majority of emerging radioisotopes, including the theranostic ones or pairs, is mainly limited by the fact that, for most of them, the optimal production route still needs to be strengthened if not defined in some cases. The aim of this work is to present a review on the charged particle induced nuclear cross sections to produce some emerging radionuclides for medical applications to show that all types of projectiles should be considered in the quest of producing medical radionuclides. An accurate analysis of the production routes is presented for some radionuclides (67Cu, 47Sc, 89Zr, 103Pd, 186gRe, 97Ru, 211At) chosen as examples to highlight (i) how the quality of the final product strongly depends on the chosen target/projectile/energy parameters set, (ii) how deuteron production routes may sometimes be more effective than the proton ones or lead to a different impurity profile and (iii) how α-particle beams may allow to bypass the limitations occurring when using Z = 1 beams. An overview of possible advantages and drawbacks of the cited production routes and of potential cross sections that still need to be measured, is also reported.

The present article describes the decommissioning of a self-shielded 18 MeV medical cyclotron IBA Cyclone 18/9 after 14 years of operation. A Monte Carlo simulation of the possible nuclear reactions was performed in order to plan the decommissioning activities. During the cyclotron dismantling, the activities of the cyclotron components, concrete wall and floor samples were measured. Residual activities were analysed by means of an HPGe detector and liquid scintillation counting, and compared with simulation data. Dosimetry of the staff involved in the decommissioning procedure was monitored by individual TL dosimeters and/or digital dosimeter. The cyclotron component analysis confirmed the presence of gamma and pure beta emitters, 22Na, 54Mn, 60Co, 65Zn, 207Bi, 55Fe, 63Ni at different values of specific activity, depending on the positioning of the sample point and on the alloy of the sampled part. In these components the presence of gamma and pure beta emitters was measured 5 years after the shutdown at levels far above clearance limits as defined by the ‘Recommended radiological protection criteria for the recycling of metals from the dismantling of nuclear installations’ (RP89) guidelines. The simulation, carried out by FLUKA Code (version 2020.0.5) on the cyclotron components, provided good agreement with measurements, with a maximum discrepancy of the same order as the uncertainties. Four engineers of the cyclotron maintenance staff were involved in the dismounting of the hottest components and rigging of the cyclotron in the deposit 6 months after shutdown and two engineers were involved during the drilling phase 3.5 years after shutdown. The measured dose from external exposure of the involved staff was lower than 100 μSv person−1 during the first phase and lower than 20 μSv person−1 during the final drilling phase. Measured doses from intake were negligible. In conclusion, the decommissioning of the 18 MeV cyclotron does not represent a risk for the involved staff, but, due to the presence of long-lived radioisotopes, the cyclotron components are to be treated as low level radioactive waste, and stored in an authorised storage area for at least 25 years after shutdown.

Manganese-52 ground (52gMn) is a positron emitter and its beneficial properties make it a strong candidate for positron emission tomography (PET) imaging. Furthermore, the PET isotope 52gMn has bee...

The physical properties of $${}^{149,152,155,161}$$ 149 , 152 , 155 , 161 Tb enable their use in both diagnostic and therapeutic applications in the field of nuclear medicine. For this reason the optimization of the production routes of these radionuclides is of widespread interest in research. In this work, the feasibility of the production of $${}^{155}$$ 155 Tb and $${}^{161}$$ 161 Tb via the nuclear reactions induced by deuterons on dysprosium target with natural isotopic abundances has been discussed. The cross sections of $${}^{nat}$$ nat Dy(d,x) reactions have been studied in the 12.5–32 MeV energetic range with the stacked-foil technique and the corresponding Thick Target Yields have been obtained. The presence of terbium and dysprosium contaminants ($${}^{156,160}$$ 156 , 160 Tb, $${}^{155,157,159}$$ 155 , 157 , 159 Dy) has been evaluated too.

Nowadays there is an increasing demand of engineering nanoparticles – ENPs – thanking the excellent characteristics and properties of the products in which nanoparticles (NPs) are used. On ...

After several years in the reactor core, irradiated nuclear fuel is handled and subsequently stored for a few years under water next to the core, to achieve thermal cooling and decay of very short-lived radionuclides. Thereafter, it might be sent to dry-cask interim storage before final disposal in a deep geological repository. Here, the spent nuclear fuel (SNF) is subject to a series of physicochemical phenomena which are of concern for the integrity of the nuclear fuel cladding. After moving the SNF from wet to dry storage, the temperature increases, then slowly decreases, leading the hydrogen in solid solution in the cladding to precipitate radially with consequent hydride growth and cladding embrittlement (Kim, 2020). Another phenomenon affecting the physical properties of the cladding during interim dry storage is the irradiation damage produced in the inner surface of the cladding by the alpha decay of the actinides present at the periphery of the pellet, particularly when the burnup at discharge is high. SNF pellets with high average burnup present larger fuel volumes at the end of their useful life due to accumulation of insoluble solid fission products and noble gases, which leads to disappearance of the as-fabricated pellet–clad gap. Further swelling is expected as a consequence of actinide decay and the accumulation of helium. This leads to larger cladding hoop stress and larger alpha decay damage. The present work first investigates the variation in diameter caused by pellet swelling in an irradiated Zircaloy-4 cladding after chemical digestion of the uranium oxide (UOx) pellet. Second, the irradiation damage produced during the 30 years elapsed since the end of irradiation in terms of displacements per atom (dpa) is studied by means of the FLUKA Monte Carlo code. The irradiation damage produced by the decay of actinides in the inner surface of the cladding extends for less than 3 % in depth. The considered cladded UOx pellet was extracted from a pressurized water reactor (PWR) fuel rod consisting of five segments, with an average burnup at discharge of 50.4 GWd (tHM)−1.

A new instrumental neutron activation analysis (INAA) for the simultaneous determination of titanium (TiO

International audience; We investigated 89Zr production induced by deuteron beams on yttrium targets at energies up to Ed = 32 MeV using the stacked-foil activation technique. Cross sections of the following nuclear reactions 89Y(d,2n)89Zr, 89Y(d,3n)88Zr and 89Y(d,x)88Y have also been measured. Based on the measured values, we determined the thick target yields for 89Zr and 88Zr which is the main contaminant associated to the production of 89Zr.

The activity size distributions of the natural radionuclide tracer 7Be in different size fractions ( 9.0 μm) were determined at four different site places in Northern Italy during the four seasons of the year 2011. One cascade impactor operated at the LASA-station considered the reference station and the other used for simultaneous measurements at the three other sites. Three sets of independent samples were collected during every season of the year 2011. The initial activity distribution inverted into smooth size distribution. The model parameters successfully defined to obtain the best fit-curve and two or three modes were resolved, with the predominant fit at the accumulation range. The lowest Activity Median Aerodynamic Diameter (AMAD) values were observed during summer. The AMAD values were anticorrelated with 7Be activities, while they were correlated with Relative Humidity. Similar AMAD values in suburban and urban regions were observed during all periods of the year. AMAD values of 7Be aerosol particles in areas with poor air quality were greater than those at the less polluted environments far from anthropogenic activities regions. This indicates that 7Be AMAD values could be used as an index of air quality conditions in areas like the Po Valley.

Background: TiO2 nanoparticles (TiO2 NPs) are the nanomaterial most produced as an ultraviolet (UV) filter. However, TiO2 is a semiconductor and, in nanoparticle size, is a strong photocatalyst, raising concerns about photomutagenesis. Mesoporous silica nanoparticles (MSN) were synthetized incorporating TiO2 NPs (TiO2@MSN) to develop a cosmetic UV filter. The aim of this study was to assess the toxicity of TiO2@MSN, compared with bare MSN and commercial TiO2 NPs, based on several biomarkers. Materials and Methods: Human peripheral blood mononuclear cells (PBMC) were exposed to TiO2@MSN, bare MSN (network) or commercial TiO2 NPs for comparison. Exposed PBMC were characterized for cell viability/apoptosis, reactive oxygen species (ROS), nuclear morphology, and cytokines secretion. Results: All the nanoparticles induced apoptosis, but only TiO2 NPs (alone or assembled into MSN) led to ROS and micronuclei. However, TiO2@MSN showed lower ROS and cytotoxicity with respect to the P25. Exposure to TiO2@MSN induced Th2-skewed and pro-fibrotic responses. Conclusions: Geno-cytotoxicity data indicate that TiO2@MSN are safer than P25 and MSN. Cytokine responses induced by TiO2@MSN are imputable to both the TiO2 NPs and MSN, and, therefore, considered of low immunotoxicological relevance. This analytical assessment might provide hints for NPs modification and deep purification to reduce the risk of health effects in the settings of their large-scale manufacturing and everyday usage by consumers.

Knowledge on Bi metabolism in laboratory animals refers to studies at "extreme" exposures, i.e. pharmacologically relevant high-doses (mg kgAnimals were intraperitoneally injected with 0.8 μg Bi kgAt 24 h post injection the kidney contained by far the highest Bi concentration (10 ng gAt the best of our knowledge the present paper represents the first in vivo study, on the basis of an environmental toxicology approach, aiming at describing retention and binding of Bi in the rat at tissue, intracellular and molecular levels.

The number of the applications of bismuth (Bi) is rapidly and remarkably increasing, enhancing the chance to increase the levels to which humans are normally daily exposed. The interest to Bi comes also from the potential of Bi-based nanoparticles (BiNPs) for industrial and biomedical purposes. Like other metal-based NPs used in nanomedicine, BiNPs may release ultratrace amounts of Bi ions when injected. The metabolic fate and toxicity of these ions still needs to be evaluated. At present, knowledge of Bi metabolism in laboratory animals refers almost solely to studies under unnatural "extreme" exposures, i.e. pharmacologically relevant high-doses (up to thousand mg kgRats were intraperitoneally injected with 0.8 μg Bi kg24 h after the administration, the blood concentration of Bi was 0.18 ng mLOn the basis of an environmental biochemical toxicology approach, we have undertaken a study on the metabolic patterns of Bi

The positron emitter

Trace metal toxicology research aimed at generating human-relevant information for risk assessment requires the use of sensitive and sophisticated analytical techniques to determine typically µg kg−1 or lower concentrations of trace metals in tissues, cells, intracellular components of laboratory animals and humans. The results of these techniques are needed for an understanding of the biochemical mechanisms and bio-transformations involving trace metals. In this context, radioanalytical and nuclear methods plays a pivotal role. In order to give an idea of typical results which can be obtained by radioanalytical and nuclear techniques when used in combination with biochemical and molecular biology techniques of cellular fractionation we report here some typical studies carried out by means of non-carrier added radiotracers with high specific activity, and neutron activation analysis (NAA). The investigations have been performed in the context of an integrated and complementary in vivo and in vitro approach that uses both animal and human test systems. Applications reported concern: (1) the in vivo work on laboratory animals (brain regional thallium distribution in rats and identification of thallium binders in testis, by means of 201+202Tl); (2) in vitro investigations on cells of animal origin (arsenic uptake and biomethylation in rat brain aggregates, neurons, microglia and astrocytes as well as speciation of vanadate in Balb/3T3 cells, by means of 73As and 48V, respectively); (3) in vitro experiments on cell of human origin (intracellular behavior of cadmium in human umbilical cord blood stem cells, by means of 109Cd); (4) analytical determinations of trace metals in tissues of general population and patients potentially affected by metal-related disease, by means of NAA. The analytical determinations carried out allowed to relate total element concentrations in cells to the results of investigations at the intracellular and molecular levels with the goal of identifying the biochemical components that interact with trace metals. These findings demonstrate the great potential of radioanalytical and nuclear techniques in the context of an integrated in vivo-in vitro strategy adopted in trace metal toxicology research for a mechanistically-based hazard characterization concerning the exposure to low doses of trace metals.

Background Knowledge on Bi metabolism in laboratory animals refers to studies at “extreme” exposures, i.e. pharmacologically relevant high-doses (mg kg−1 b.w.) in relation to its medical use, or infinitesimal doses (pg kg−1b.w.) concerning radiobiology protection and radiotherapeutic purposes. There are no specific studies on metabolic patterns of environmental exposure doses (ultratrace level, μg kg−1 b.w.), becoming in this context Bi a “heavy metal fallen into oblivion”. We previously reported the results of the metabolic fate of ultratrace levels of Bi in the blood of rats [ 1 ]. In reference to the same study here we report the results of the retention and tissue binding of Bi with intracellular and molecular components. Methods Animals were intraperitoneally injected with 0.8 μg Bi kg−1 b.w. as 205+206Bi(NO)3, alone or in combination with 59Fe for the radiolabeling of iron proteins. The use of 205+206Bi radiotracer allowed the determination of Bi down to pg fg−1 in biological fluids, tissues, subcellular fractions, and biochemical components isolated by differential centrifugation, size exclusion chromatography, solvent extraction, precipitation, immunoprecipitation and dialysis. Main findings At 24 h post injection the kidney contained by far the highest Bi concentration (10 ng g−1 wt.w.) followed by the thymus, spleen, liver, thyroid, trachea, femur, lung, adrenal gland, stomach, duodenum and pancreas (0.1 to 1.3 ng g−1 wt.w.). Brain and testis showed smaller but consistently significant concentrations of the element (0.03 ng g−1 wt.w). Urine was the predominant route of excretion. Intracellularly, liver, kidney, spleen, testis, and brain cytosols displayed the highest percentages (35%–58%) of Bi of homogenates. Liver and testis nuclei were the organelles with the highest Bi content (24 % and 27 %). However, when the recovered Bi of the liver was recorded as percent of total recovered Bi divided by percent of total recovered protein the lysosomes showed the highest relative specific activity than in other fractions. In the brain subcellular fractions Bi was incorporated by neuro-structures with the protein and not lipidic fraction of the myelin retaining 18 % of Bi of the total homogenate. After the liver intra-subcellular fractionation: (i) 65 % of the nuclear Bi was associated with the protein fraction of the nuclear membranes and 35 % with the bulk chromatin bound to non-histone and DNA fractions; (ii) about 50 % of the mitochondrial Bi was associated with inner and outer membranes being the other half recovered in the intramitochondrial matrix; (iii) in microsomes Bi showed a high affinity (close to 90 %) for the membranous components (rough and smooth membranes); (iv) In the liver cytosol three pools of Bi-binding proteins (molecular size > 300 kDa, 70 kDa and 10 kDa) were observed with ferritin and metallothionein–like protein identified as Bi-binding biomolecules. Three similar protein pools were also observed in the kidney cytosol. However, the amount of Bi, calculated in percent of the total cytosolic Bi, were significantly different compared to the corresponding pools of the liver cytosol. Conclusions At the best of our knowledge the present paper represents the first in vivo study, on the basis of an environmental toxicology approach, aiming at describing retention and binding of Bi in the rat at tissue, intracellular and molecular levels.

Background The number of the applications of bismuth (Bi) is rapidly and remarkably increasing, enhancing the chance to increase the levels to which humans are normally daily exposed. The interest to Bi comes also from the potential of Bi-based nanoparticles (BiNPs) for industrial and biomedical purposes. Like other metal-based NPs used in nanomedicine, BiNPs may release ultratrace amounts of Bi ions when injected. The metabolic fate and toxicity of these ions still needs to be evaluated. At present, knowledge of Bi metabolism in laboratory animals refers almost solely to studies under unnatural “extreme” exposures, i.e. pharmacologically relevant high-doses (up to thousand mg kg−1) in relation to its medical use, or infinitesimal-doses (pg kg−1 as non-carrier-added Bi radioisotopes) for radiobiology protection, diagnostic and radiotherapeutic purposes. No specific study exists on the “metabolic patterns” in animal models exposed to levels of Bi, i.e. at “environmental dose exposure” that reflect the human daily exposure (μg kg−1). Methodology Rats were intraperitoneally injected with 0.8 μg Bi kg−1 bw as 205+206Bi(NO)3 alone or in combination with 59Fe for radiolabelling of iron proteins. The use of 205+206Bi radiotracers allowed the detection and measurement down to pg fg−1 of the element in the blood biochemical compartments and protein fractions as isolated by differential centrifugation, size exclusion- and ion exchange chromatography, electrophoresis, solvent extraction, precipitation and dialysis. Results 24 h after the administration, the blood concentration of Bi was 0.18 ng mL−1, with a repartition plasma/red blod cells (RBC) in a ratio of 2:1. Elution profiles of plasma from gel filtration on Sephadex G-150 showed four pools of Bi-binder proteins with different molecular sizes (> 300 kDa, 160 kDa, 70 kDa and Conclusions On the basis of an environmental biochemical toxicology approach, we have undertaken a study on the metabolic patterns of Bi3+ ions in rats at tissue, subcellular and molecular level with the identification of cellular Bi-binding components. As a first part of the study the present work reports the results concerned with the metabolic fate of ultratrace levels of 205+206Bi(NO)3 in the blood.

Deuteron-induced nuclear reactions for the generation of 103Pd were investigated using the stacked-foil activation technique on rhodium targets at deuteron energies up to Ed=33MeV. The excitation functions of the reactions 103Rh(d,xn)101,103Pd, 103Rh(d,x)100g,cum,101m,g,102m,gRh and 103Rh(d,2p)103Ru have been measured, and the Thick-Target Yield for 103Pd has been calculated.

Background: TiO2 nanoparticles (TiO2 NPs) are the nanomaterial most produced as an ultraviolet (UV) filter. However, TiO2 is a semiconductor and, in nanoparticle size, is a strong photocatalyst, raising concerns about photomutagenesis. Mesoporous silica nanoparticles (MSN) were synthetized incorporating TiO2 NPs (TiO2@MSN) to develop a cosmetic UV filter. The aim of this study was to assess the toxicity of TiO2@MSN, compared with bare MSN and commercial TiO2 NPs, based on several biomarkers. Materials and Methods: Human peripheral blood mononuclear cells (PBMC) were exposed to TiO2@MSN, bare MSN (network) or commercial TiO2 NPs for comparison. Exposed PBMC were characterized for cell viability/apoptosis, reactive oxygen species (ROS), nuclear morphology, and cytokines secretion. Results: All the nanoparticles induced apoptosis, but only TiO2 NPs (alone or assembled into MSN) led to ROS and micronuclei. However, TiO2@MSN showed lower ROS and cytotoxicity with respect to the P25. Exposure to TiO2@MSN induced Th2-skewed and pro-fibrotic responses. Conclusions: Geno-cytotoxicity data indicate that TiO2@MSN are safer than P25 and MSN. Cytokine responses induced by TiO2@MSN are imputable to both the TiO2 NPs and MSN, and, therefore, considered of low immunotoxicological relevance. This analytical assessment might provide hints for NPs modification and deep purification to reduce the risk of health effects in the settings of their large-scale manufacturing and everyday usage by consumers.

Right after the Fukushima reactor accident, a systematic air and wet sampling and analysis programme was undertaken to detect and quantitatively analyze the radionuclides in the Fukushima fallout in Milano, Italy. Radionuclides from Fukushima were first detected at Milano region in a rain water sample, collected during March 27-28, 2011 with the concentrations of 131 I and 137 Cs isotopes in the rainwater to be equal with 0.89 Bq/L and 0.12 Bq/L , respectively. The concentration of 131 I in goat and cow milk samples from a farm in Monte Rosa mountain, were 0.25 and 0.21 Bq/L , respectively. Increased atmospheric radioactivity was detected on air filter taken on 30 March 2011, while the maximum activity of 467 μBq/m 3 occurred at April 3-4, 2011. A week later the activities had fallen to about 50% of peak values, with a general increasing trend over the following days. In the time period of one month after the nuclear accident, concentrations of 137 Cs and 134 Cs in air as high as 63 μBq/m 3 and 61 μBq/m 3 , respectively were recorded. The presence of more than one peaks of 131 I and 137,134 Cs till April 11, 2011, indicates that 131 I and 137,134 Cs were continuously transferred from Fukushima, Japan to Italy. According to the measurements, airborne activity levels remain of no concern for public health in Italy.

The fast neutrons produced by a calibrated 241Am-Be source were detected by two different Cs2LiYCl6:Ce (CLYC) scintillator detectors. The two cylindrical crystals (1''× 1'' in size) were enriched with more than 99% of 7Li (C7LYC) and with about 95% of 6Li (C6LYC), respectively. Both crystals can detect fast neutrons whereas only C6LYC can also detect thermal neutrons, due to the presence of 6Li. The measurement was performed at the L.A.S.A . Laboratory of INFN and University of Milano (Italy). To identify the neutron events, the Pulse-Shape-Discrimination technique was used. The values of 1.41 ± 0.16 for C6LYC and 1.16 ± 0.21 for C7LYC for the detection efficiency of the 241Am-Be emitted neutrons, with energy up to 10 MeV, were deduced.

Theragnostic medicine is a new integrated therapeutic system which can diagnose, deliver targeted therapy, and monitor the response to therapy. Many of the “neutron-rich” radionuclides suitable for metabolic radiotherapy are produced by nuclear reactor with a very low specific activity (A S). In selected cases, they can be produced by bombardment of targets by charged particle beams in “No Carrier Added Form” with very high A S. If the irradiations are made with deuteron beams some more advantages are obtained, as described in this paper, through 186gRe production, reported as an example.

The use of platinum, palladium and rhodium (Platinum Group Elements - PGEs) and the possibility of exposure to their ultratrace levels is increasing. In fact, the exponential development of metallic PGE-based nanoparticles (100 nm in size) opens extraordinary perspectives in the areas of electrocatalysts and catalytic converters, magnetic nanopowders, polymer membranes, cancer therapy, coatings, plastics, nanofibres and textiles. Like other metal-based nanoparticles, exposure to PGEs nanoparticles may result in a release of ultratrace amounts of Pt, Pd, Rh ions in the body whose metabolic fate and toxicity still need to be evaluated. Furthermore, PGEs can act as allergic sensitizers by acting as haptens and inducing both type I and IV allergic reactions. In this work we studied the in vivo metabolic patterns of ultratrace levels of potent allergens and sensitizers PGE halogenated salts. (191)Pt, (103)Pd and (101m)Rh radioisotopes were prepared via cyclotron irradiation and used for radiolabelling Na2(191)PtCl4, Na2(103)PdCl4 and Na2(101m)RhCl6 salts. These anionic chlorocomplexes were intraperitoneally injected into rats (114 ng Pt kg(-1) bodyweight; 24 ng Pd kg(-1) b.w.; 16 ng Rh kg(-1) b.w.). At 16 h post-exposure, PGEs were poorly but significantly retained in all tissues analysed. Kidneys, spleen, adrenal gland, liver, pancreas and small intestine were the organs with the highest Pt, Pd, Rh concentrations. In the blood 30-35% of (103)Pd and (191)Pt and 10% of (101m)Rh were recovered in the plasma, mainly bound to albumin and to a less extent to transferrin. The hepatic and renal intracellular distribution showed the highest recovery of (191)Pt, (103)Pd and (101m)Rh in the nuclear fraction (liver) and in the cytosol (kidney). Chromatographic separation and ultrafiltration experiments on kidney and liver cytosols showed the strong ability of biochemical macromolecules to bind (191)Pt, (103)Pd and (101m)Rh, and being responsible for the retention of the three elements in the body. The link to macromolecules is the basis for the sensitizing capacity of PGEs.

Proton-induced nuclear reactions for generation of (99)Mo and (99m)Tc radionuclides were investigated using the stacked-foil activation technique on 99.05% enriched (100)Mo targets at energies up to Ep=21MeV. Excitation functions of the reactions (100)Mo(p,x)(99)Mo and (100)Mo(p,2n)(99m)Tc have been measured.

Excitation functions, thin- and thick-target yields for the 181−186gRe and 187W radionuclides were measured by the activation stacked-foil thecnique on natural tungsten foils for deuteron energies up to 18.0 MeV. These cross sections were validated by comparing the experimental results for thick-target yields with those calculated by integration of the thin-target yields. It was found that the maximum 186gRe content by irradiation of natural tungsten is about 55%, a higher value compared with the one found for proton beam, but not sufficient to use natural tungsten for medical purposes yet. Thus, in order to have a higher specific activity A S of 186gRe, the use of enriched 186W target is necessary. Therefore the irradiation of a thick target of enriched 186W by accelerated deuterons was studied and the results for the production of 186gRe were compared with those obtained from the irradiation of the same target by accelerated protons. It was found that the deuteron irradiation is preferable for three reasons: larger yield, less contamination by tantalum radioisotopes and smaller required amount of the target, which simplify the separation of the 186gRe from the target itself.

The activity size distributions of the natural radionuclide tracer 7Be in different size fractions (9.0 μm) were determined at different site places in Northern Italy. Samplings were carried out during the four different seasons of the year 2011. The aim of this work was to define any differences due to the different environments and different meteorological conditions and clarify the main parameters influencing the activity size distribution of radioactive aerosols.

131I, 137Cs and 134Cs were observed in environmental samples in Milano (40°N), Italy and Thessaloniki (45°N), Greece, soon after the nuclear accident in Fukushima, Japan. The radionuclide concentrations were determined and studied as a function of time. In Thessaloniki the 131I in air was observed for the first time on March 24, 2011. In Milano, the first evidence of Fukushima fallout has been confirmed with 131I and 137Cs measured in wet precipitation collected 2 days later. The maximum 131I activity concentration in air of 467 ± 25 μBq m−3, observed in Milano on April 3–4, 2011, was almost similar to the highest value of 497 ± 53 μBq m−3 observed in Thessaloniki. The 134Cs/137Cs activity ratio values in air were around 1 in both regions. Soil, grass and milk samples were contaminated with 131I and 137Cs at a low level. Finally, a dose assessment for these two areas showed clearly that the detected activities in all environmental samples were far below levels of concern.

Analyses of 131I, 137Cs and 134Cs in airborne aerosols were carried out in daily samples at two different sites of investigation: Thessaloniki, Greece (40° N) and Milan, Italy (45° N) after the Fukushima accident during the period of March–April, 2011. The radionuclide concentrations were determined and studied as a function of time. The 131I concentration in air over Milan and Thessaloniki peaked on April 3–4, 2011, with observed activities 467 μBq m−3 and 497 μBq m−3, respectively. The 134Cs/137Cs activity ratio values in air were around 1 in both regions, related to the burn-up history of the damaged nuclear fuel of the destroyed nuclear reactor. The high 131I/137Cs ratio, observed during the first days after the accident, followed by lower values during the following days, reflects not only the initial release ratio but also the different volatility, attachment and removal of the two isotopes during transportation due to their different physico-chemical properties. No artificial radionuclides could be detected in air after April 28, 2011 in both regions of investigation. The different maxima of airborne 131I and 134,137Cs in these two regions were related to long-range air mass transport from Japan, across the Pacific and to Central Europe. Analysis of backward trajectories was used to confirm the arrival of artificial radionuclides following atmospheric transport and processing. HYSPLIT backward trajectories were applied for the interpretation of activity variations of measured radionuclides.

The radionuclides 131 I, 137 Cs and 134 Cs were observed in the Milano region (45°) of Italy early after the nuclear accident in Fukushima, Japan. Increased atmospheric radioactivity was observed on an air filter taken on 30 March 2011, while the maximum activity of 467 μBq m −3 for 131 I was recorded at April 3–4, 2011. The first evidence of Fukushima fallout was confirmed with 131 I and 137 Cs measured in precipitation at two sampling sites at Milano on 28 March, 2011, with the concentrations of 131 I and 137 Cs in the rainwater equal to 0.89 Bq L −1 and 0.12 Bq L −1 , respectively. A sample of dry deposition that was collected 9 days after the first rainfall event of 27–28 March, 2011 showed that the dry deposition was more effective in the case of 137 Cs than it was for 131 I, probably because iodine was mainly in gaseous form whereas caesium was rapidly bound to aerosols and thus highly subject to dry deposition. The relatively high observed values of 137 Cs in grass, soil and fresh goat and cow milk samples were probably from Chernobyl fallout and global fallout from past nuclear tests rather than from the Fukushima accident. Finally, a dose assessment for the region of investigation showed clearly that the detected activities in all environmental samples were very far below levels of concern.

Potential environmental impacts of engineered nanoparticles (ENPs) can be understood taking into consideration phytotoxicity. We reported on the effects of ionic (FeCl3), micro- and nano-sized zerovalent iron (nZVI) about the development of three macrophytes: Lepidium sativum, Sinapis alba and Sorghum saccharatum. Four toxicity indicators (seed germination, seedling elongation, germination index and biomass) were assessed following exposure to each iron concentration interval: 1.29–1570 mg/L (FeCl3), 1.71–10.78 mg/L (micro-sized iron) and 4.81–33,560 mg/L (nano-iron). Exposure effects were also observed by optical and transmission electron microscopy. Results showed that no significant phytotoxicity effects could be detected for both micro- and nano-sized zerovalent irons, including field nanoremediation concentrations. Biostimulation effects such as an increased seedling length and biomass production were detected at the highest exposure concentrations. Ionic iron showed slight toxicity effects only at 1570 mg/L and, therefore, no median effect concentrations were determined. By microscopy, ENPs were not found in palisade cells or xylem. Apparently, aggregates of nZVI were found inside S. alba and S. saccharatum, although false positives during sample preparation cannot be excluded. Macroscopically, black spots and coatings were detected on roots of all species especially at the most concentrated treatments.

Deuteron-induced nuclear reactions for generation of no-carrier-added Lu radionuclides were investigated using the stacked-foil activation technique on natural Yb targets at energies up to E(d)=18.18 MeV. Excitation functions of the reactions (nat)Yb(d,xn)(169,170,171,172,173,174g,174m,176m,177g)Lu and (nat)Yb(d,pxn)(169,175,177)Yb have been measured, among them three ((169)Lu, (174m)Lu and (176m)Lu) are reported for the first time. The upper limit of the contamination from the long-lived metastable level (177m)Lu was evaluated too. Thick-target yields for all investigated radionuclides are calculated.

Deuteron-induced nuclear reactions for generation of no-carrier-added (NCA) Lu isotopes were investigated using the stacked-foil activation technique on natural Yb targets at energies up to E d = 18.18 MeV. The decay curve of 177 Yb, the growth curve of the cumulative (direct and indirect) and the direct production of 177g Lu were determined. The analysis of these curves conducts to the evidence that the predominant route for the production of 177g Lu is the indirect reaction 176 Yb(d,p) 177 Yb, which decays to 177g Lu. In the spectra acquired one year from the EOB the γ lines of 177m Lu are not evident. A comparison between the calculated activity of 177g Lu produced with a cyclotron and with a nuclear reactor is given.

Excitation functions and thin-target yields for the181-186gRe radionuclides have been measured by the stacked-foil activation technique on tungsten foils of natural isotopic composition for different proton energies up to 22.0 MeV. A further check on the cross sections was done by irradiation of thick-targets and comparing the irradiated thick-target yields with those calculated by analytical integration from the thin-target yields. The production of186gRe was also studied by the irradiation of thick-target of enriched186W with a 13.6±0.2 MeV proton beam. The results for186W(p,ߙn)186gRe were compared also to those calculated by the EMPIRE II code (version 2.19), due to186gRe extensive applications in nuclear medicine for metabolic radiotherapy of tumours. It was found that the maximum percentage of186gRe by irradiation of natural tungsten is about 20% only, which confirms the conclusion that high radionuclidic purity and specific activity of186gRe necessitate the use of highly enriched186W target.

Evaluation of the radioisotopic purity of technetium-99m (99mTc) produced in GBq amounts by proton bombardment of enriched molibdenum-100 (100Mo) metallic targets at low proton energies (i.e. within 15-20 MeV) is conducted. This energy range was chosen since it is easily achievable by many conventional medical cyclotrons already available in the nuclear medicine departments of hospitals. The main motivation for such a study is in the framework of the research activities at the international level that have been conducted over the last few years to develop alternative production routes for the most widespread radioisotope used in medical imaging. The analysis of technetium isotopes and isomeric states (9xTc) present in the pertechnetate saline Na99mTcO4 solutions, obtained after the extraction/purification procedure, reveals radionuclidic purity levels basically in compliance with the limits recently issued by European Pharmacopoeia 9.3 (2018 Sodium pertechnetate (99mTc) injection 4801-3). Moreover, the impact of 9xTc contaminant nuclides on the final image quality is thoroughly evaluated, analyzing the emitted high-energy gamma rays and their influence on the image quality. The spatial resolution of images from cyclotron-produced 99mTc acquired with a mini-gamma camera was determined and compared with that obtained using technetium-99m solutions eluted from standard 99Mo/99mTc generators. The effect of the increased image background contribution due to Compton-scattered higher-energy gamma rays (E γ > 200 keV), which could cause image-contrast deterioration, was also studied. It is concluded that, due to the high radionuclidic purity of cyclotron-produced 99mTc using 100Mo(p,2n)99mTc reaction at a proton beam energy in the range 15.7-19.4 MeV, the resulting image properties are well comparable with those from the generator-eluted 99mTc.

Very high specific activity (AS) 186gRe could be produced by either proton or deuteron cyclotron irradiation on highly enriched 186W target in no-carrier-added (NCA) form, leading to a AS very close to the theoretical carrier free (CF) value of 6.88 GBq lg-1. Thick Target Yields (TTYs), obtained irradiating both thick metal W targets of natural isotopic composition and highly enriched powdered 186W targets, were measured at different particles energies taking into account high accuracy and precision. The evaluation of radionuclidic purities of 186gRe obtained activating highly enriched 186W by both p and d were also carried out and accurately compared. The thin-target excitation functions for all Re (A = 181, 182, 183, 184, 186 and their metastable levels), and W and Ta coproduced radionuclides will be presented elsewhere in deep details., JRC.I.4-Nanobiosciences

(75)Se-selenite transfer was investigated in a phytoplankton-mussel-rat food chain model consisting of Scenedesmus obliquus (Turpin) Kützing, Unio mancus Lamark and Rattus norvegicus Berkenhout. (75)Se-metabolized forms were investigated in order to identify potential critical steps in the food chain, as well as its relative bioavailability looking also at intracellular, cellular and organ partitioning. Tissue and intracellular distribution of (75)Se in mussels fed with (75)Se-S. obliquus was different compared to those exposed only to inorganic (75)Se-selenite. The intracellular distribution of (75)Se in the hepatopancreas and mantle of mussels fed (75)Se-microalgae was similar to hepatic and renal distributions in rats, suggesting that their stomach dissociated larger (75)Se-containing molecules. The (75)Se partitioned from water (culture medium) to microalgae showing a bioconcentration factor of 435. The bottleneck in the trophic transfer of (75)Se occurred between S. obliquus-U. mancus. From microalgae to mussels and subsequently to rats no bioaccumulation was verified.

O presente estudo teve por objetivos: 1) verificar a incidência de ocorrências adversas (OAs) com medicação relacionadas ao tempo de infusão das soluções hidroeletrolíticas e ao número de doses de antibióticos prescritos e administrados aos pacientes; 2) caracterizar a natureza dessas ocorrências. A investigação foi realizada em duas UTIs de um hospital geral do Município de São Paulo. Fizeram parte do estudo os dados contidos nos prontuários de 51 pacientes que estiveram internados naquelas Unidades no mês de Agosto de 1996. Quanto à caracterização dos pacientes, 60% tinham idade acima de 60 anos, 58,8% eram mulheres, 49,1% permaneceram na UTI entre 1 e 5 dias e, ao saírem dela, 41,2 % foram para a Unidade de Cuidados Semi-Intensivos. Referente à incidência de 0As relacionadas ao tempo de administração das soluções hidroeletrolíticas e ao número de doses de antibióticos, constatou-se o não cumprimento das prescrições médicas dos pacientes, em 76,3% e 38,6%, respectivamente. A maior freqüência de irregularidades quanto aos soros (60,2%) foi referente a administração em tempo menor que o prescrito (adiantamentos) e, no caso dos antibióticos, a redução do número de doses (85%). Considerando-se tais irregularidades como ocorrências indesejáveis na prática da enfermagem na UTI, há que se investir na busca de medidas preventivas dessas ocorrências. The aims of this study were: 1) to verify the incidence of adverse occurences (AO) with medication related to the time of electrolyte solutions infusion and the frequency of doses of antibiotics prescribed and administered to the patients; 2) to characterize the nature of those occurences. The study was developed in two ICUs of a general hospital of São Paulo City. The population was composed by 51 patients that were in the ICUs in August of 1996. Sixty percent of the patients were older than 60 years, 58,8% were women, 49,1% remained in ICU from 1 to 4 days and 41,2% went to the Intermediate Care Units after ICU. Regarding the incidence of AOs related to the time of administration of the electrolyte solutions and the frequency of doses of antibiotics the non execution of the patient's medical prescriptions was verified in 76,3% and 38,8% respectively. The largest frequency of irregularies with the electrolyte solutions (60,2%) was the infusion faster than the prescribed time followed by the reduction of the number of doses of antibiotics administered. Taking these into consideration we have to invest in preventive measures to reduce those occurrences.

The CLYC (Cs2LiYC6:Ce) crystal belongs to the elpasolite scintillator family, discovered about 15 years ago. It is a very interesting material because of its good energy resolution and its capability to identify and measure gamma rays and fast/thermal neutrons. In the present work, the fast neutron detection efficiency for two different CLYC cylindrical samples has been measured. These two crystals, both with dimension (thickness x diameter) 1"×1", were respectively enriched with more than 99% of 7Li (CLYC-7) and with ~ 95% of 6Li (CLYC-6). The presence of the 6Li isotope makes the CLYC-6 ideal to detect thermal neutrons. In order to compare the two scintillators, only the detection efficiency for fast neutrons was considered, neglecting the energy region associated to thermal neutrons in both the crystals. The measurement was performed at the L.A.S.A. Laboratory of INFN and University of Milano (Italy), using a 241Am-Be source.

Radioactive emissions into the atmosphere from the damaged reactors of the Fukushima Dai-ichi nuclear power plant (NPP) started on March 12th, 2011. Among the various radionuclides released, iodine-131 ( 131I) and cesium isotopes ( 137Cs and 134Cs) were transported across the Pacific toward the North American continent and reached Europe despite dispersion and washout along the route of the contaminated air masses. In Europe, the first signs of the releases were detected 7 days later while the first peak of activity level was observed between March 28th and March 30th. Time variations over a 20-day period and spatial variations across more than 150 sampling locations in Europe made it possible to characterize the contaminated air masses. After the Chernobyl accident, only a few measurements of the gaseous 131I fraction were conducted compared to the number of measurements for the particulate fraction. Several studies had already pointed out the importance of the gaseous 131I and the large underestimation of the total 131I airborne activity level, and subsequent calculations of inhalation dose, if neglected. The measurements made across Europe following the releases from the Fukushima NPP reactors have provided a significant amount of new data on the ratio of the gaseous 131I fraction to total 131I, both on a spatial scale and its temporal variation. It can be pointed out that during the Fukushima event, the 134Cs to 137Cs ratio proved to be different from that observed after the Chernobyl accident. The data set provided in this paper is the most comprehensive survey of the main relevant airborne radionuclides from the Fukushima reactors, measured across Europe. A rough estimate of the total 131I inventory that has passed over Europe during this period was \textless1% of the released amount. According to the measurements, airborne activity levels remain of no concern for public health in Europe. © 2011 American Chemical Society.