Large-scale production of lutetium-177m for the 177mLu/177Lu radionuclide generator.

In this work, 177mLu has been produced by irradiation of natural Lu2O3 targets at the BR2 reactor (Mol, Belgium) and the obtained data together with literature values have been used to theoretically investigate the production of 177mLu at different neutron fluxes, irradiation times and enrichment of 176Lu. The irradiation time (tmax) needed to reach the maximum 177mLu production has been found to change from 42, 12, 4 days with the increase in the thermal neutron flux from 2*1014, 8*1014, 2.5*1015 n cm-2 s-1, respectively while keeping the maximum 177mLu activity unaffected. The results of our calculations suggest that 0.11 TBq 177mLu with a specific activity of 0.3 TBq g-1 Lu can be produced in a short irradiation time of 4 days using 1g of 84.44% 176Lu enriched Lu2O3 and a thermal neutron flux of 2.5*1015 n cm-2 s-1.

Measurement of the enriched stable isotope 58Fe in iron related disorders- comparison of INAA and MC-ICP-MS.

As a safer alternative for the use of radioactive tracers, the enriched stable 58Fe isotope has been introduced in studies of iron metabolism. In this study this isotope is measured with instrumental neutron activation analysis (INAA) in blood samples of patients with iron related disorders and controls after oral ingestion of a 58Fe containing pharmaceutical. Results were compared with those derived from MC-ICP-MS, applied on the same samples, and analytical and practical aspects of the two techniques were compared. Both techniques showed an increased absorption and incorporation in red blood cells of the 58Fe isotope in iron deficient patients in contrast to the controls. In all individuals results of INAA measurements were in good agreement with those of MC-ICP-MS (|zeta| < 2). Uncertainties in INAA are substantially higher than those achievable by MC-ICP-MS but the INAA technique offers a high specificity and selectivity for iron close to 100%. In contrast to INAA, sample preparation before measurement is very critical in MC-ICP-MS and interferences with 58Ni and 54Cr may hamper the measurement of 58Fe and 54Fe respectively. Since it takes at least five days after irradiation to reduce the activity of interfering radionuclides (mainly 24Na), INAA is a more time consuming procedure; the need of a nuclear reactor facility makes it also less accessible than MC-ICP-MS. Costs are comparable. Both INAA and MC-ICP-MS are able to adequately measure changes in iron isotope composition in blood when an enriched stable iron isotope is applied in clinical research. Although MC-ICP-MS is more sensitive, is faster and has easier access, in INAA preparative steps before measurement are simpler and there are hardly demands on the kind and size of the samples. This may be relevant working with biomaterials in a clinical setting.

Reversed phase free ion selective radiotracer extraction (RP-FISRE): a new tool to assess the dynamic stabilities of metal (-organic) complexes, for complex half-lives spanning six orders of magnitude.

This paper introduces reversed phase free ion selective radiotracer extraction (RP-FISRE) as a new tool to assess the stability of metal complexes, as illustrated by the assessment of the stability of [(177)Lu]Lu-DOTA-octreotate. To this end, the TUDelft-developed FISRE, where the released metal is column-retained and the complex eluted, was changed into RP-FISRE, where the complex is column-retained and the released metal is eluted. This change in the approach allows for studies to be performed with high stability complexes. This paper presents RP-FISRE, the strength of the radiotracer approach, and the first-ever kd data on the release of (177)Lu from [(177)Lu]Lu-DOTA-octreotate.

Biomonitoreo de la contaminación atmosférica en La Habana durante la campaña 2004-2005 / Biomonitoring of the atmospheric pollution in Havana during 2004-2005 survey

RESUMEN Para evaluar la calidad del aire en La Habana se utilizó como bioindicador una especie de liquen epífi to (physcia alba sp.) que crece sobre Palma real (Roystonea regia). Se colectó un total de 225 muestras de líquenes en 181 sitios seleccionados de acuerdo con las condiciones de contaminación por tráfi co y actividades industriales. Se determinaron las concentraciones de 15 elementos (Na, Mg, Al, Ca, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sr, Cd and Pb), empleando espectrofotometría de absorción atómica, fluorescencia de rayos X por refl exión total y voltametría de redisolución anódica. Se aplicaron métodos estadísticos (componentes principales) a los resultados analíticos y se obtuvieron y seleccionaron varios factores. Por último se presentan mapas con los perfiles de distribución elementales y de factores y su posible correlación con distintas fuentes de contaminación.

ABSTRACT An epiphytic lichen (physcia alba sp.) grown over Royal Palm (Roystonea regia) tree was used as bioindicator of air quality in Havana City. A total of 225 lichen samples were collected in 181 selected sites according to traffic and industrial conditions. The concentrations of 15 elements (Na, Mg, Al, Ca, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sr, Cd and Pb) were determined by Atomic Absorption Spectrophotometry, Total Reflection X-Ray Fluorescence and Anodic Stripping Voltammetry. Principal Component Analysis was applied to analytical results and some factors were obtained. Finally, maps with lichen elemental contents and factors’ patterns are presented. Several possible pollution sources were identified.

Is there a future for biomonitoring of elemental air pollution? A review focused on a larger-scaled health-related (epidemiological) context.

The present paper focuses on biomonitoring of elemental atmospheric pollution, which is reviewed in terms of larger-scaled biomonitoring surveys in an epidemiological context. Based on the literature information, today's availability of solar-powered small air filter samplers and fibrous ion exchange materials is regarded as adequate or an even better alternative for biomonitor transplant materials used in small-scaled set-ups, but biomonitors remain valuable in larger-scaled set-ups and in unforeseen releases and accidental situations. In the latter case, in-situ biomonitoring is seen as the only option for a retrospective study: biomoniors are there before one even knows that they are needed. For biomonitoring, nuclear analytical techniques are discussed as key techniques, especially because of the necessary multi-element assessments in both source recognition and single-element interpretation. To live up to the demands in an epidemiological context, larger-scaled in-situ biomonitoring asks for large numbers of samples, and consequently, for large total sample masses, this all to ensure representation of both local situations and survey area characteristics. Possibly, this point should direct studies into new "easy-to-sample" biomonitor organisms, of which high masses and numbers may be obtained in field work, rather than continue with biomonitors such as lichens. This also means that both sample handling and processing are of key importance in these studies. To avoid problems in comparability of analytical general procedures in milling, homogenization and digestion of samples of large masses, the paper proposes to involve only few but high-quality laboratories in the total element assessment routines. In this respect, facilities that can handle large sample masses in the assessment of element concentrations are to be preferred. This all highlights the involvement of large-sample-volume nuclear facilities, which, however, should be upgraded and automated in their operation to ensure the necessary sample throughput in larger-scaled biomonitoring.

Biomonitoring of trace element air pollution: principles, possibilities and perspectives.

This paper discusses the biomonitoring of trace element air pollution. Much attention is given to both lichens and mosses as the dominant plant species used in biomonitoring surveys. Biomonitoring is regarded as a means to assess trace element concentrations in aerosols and deposition. This implies that the monitor should concentrate the elements of interest and quantitatively reflect its elemental ambient conditions. Environmental impact on the biomonitor's behaviour is viewed as resulting in changes in the dose-response relationships. The current literature is briefly reviewed, for plant's behaviour modelling, for laboratory studies on physiological processes responsible for accumulation, retention and release, and for field work on quantification of dose-response relationships. Monitoring of elemental atmospheric availability is presented as deriving its relevance from presumed impact on both ecosystem performance and human health; source apportionment is regarded as an important parallel result for purposes of emission regulatory management. For source apportionment, the paper argues in favor of multi-elemental determinations, supplemented by information on organic compounds and elemental chemical forms. Furthermore, the discussion points towards more explicit coupling of biomonitoring data to knowledge and databases on both emission registration, ecosystem performance and human health. This means that multidisciplinary programs should be set up, which accommodate expert inputs from biomonitoring, emission control programs, analytical chemistry, ecology, and epidemiology.