Susana Sousa Gomes

The development of pharmacologically active compounds based on bis(thiosemicarbazones) (BTSC) and on their coordination to metal centers constitutes a promising field of research. We have recently explored this class of ligands and their Cu(II) complexes for the design of cancer theranostics agents with enhanced uptake by tumoral cells. In the present work, we expand our focus to aliphatic and aromatic BTSC Zn(II) complexes bearing piperidine/morpholine pendant arms. The new complexes ZnL-ZnL were characterized by a variety of analytical techniques, which included single-crystal X-ray crystallography for ZnL and ZnL. Taking advantage of the fluorescent properties of the aromatic complexes, we investigated their cellular uptake kinetics and subcellular localization. Furthermore, we tried to elucidate the mechanism of action of the cytotoxic effect observed in human cancer cell line models. The results show that the aliphatic complexes (ZnL and ZnL) have a symmetrical structure, while...

A set of bronzes recovered from Fraga dos Corvos (Macedo de Cavaleiros) archaeological site, located in Northern Portugal, was analyzed to investigate their lead isotope ratios. The studied metallic artefacts have diverse typologies and include two bar fragments, four fibulae, a pendant and fragments of a possible cauldron. Besides these, two metallurgical remains (nodule and droplet) were also analyzed. Elemental analysis by -EDXRF showed that bronzes have a Sn content varying between 5.1 and 13.9% and a Pb content from 1.4 to 6.1%, which allowed to select a suitable methodology for lead separation, prior to isotope ratio determinations. In these alloys the Pb isotope determinations (204Pb, 206Pb, 207Pb and 208Pb) are influenced by matrix effects that decrease the sensitivity and the reproducibility of the measurements. Analytical procedure consisted in electrochemical Pb separation by anodic oxidation. The determination of Pb isotope ratios was made by ICP-MS with a quadrupole mass filter and provided the first results of Pb isotopic composition of bronze alloys from the Northern Portuguese territory. Isotope ratios determinations were obtained with a relative standard deviation below 0.5%. Pb isotope ratio distributions allowed the identification of different composition patterns indicating probable distinct provenances, although the similar isotopic ratios among some artefacts and the metallurgical remains pointed out to local metallurgical activities.

Localización: Avances y tendencias en fitoplancton tóxico y biotoxinas: actas de la IX Reunión Ibérica sobre Fitoplancton Tóxico y Biotoxinas, Cartagena 7-10 de mayo de 2007/coord. por Javier Gilabert, 2008, ISBN 978-84-96997-06-6, págs. 181-186

Localización: Avances y tendencias en fitoplancton tóxico y biotoxinas: actas de la IX Reunión Ibérica sobre Fitoplancton Tóxico y Biotoxinas, Cartagena 7-10 de mayo de 2007/coord. por Javier Gilabert, 2008, ISBN 978-84-96997-06-6, págs. 199-204

The present study aims to contribute to the identification of mineral deposits used as raw source in the production of glandes plumbeae, accidentally recovered in Alto dos Cacos (Almeirim) and attributed to the Roman Period, and some bronze alloys, recovered from Fraga dos Corvos (Macedo de Cavaleiros) Bronze Age archaeological site. Therefore, methodologies to determine the lead isotope ratios in small samples taken from the archaeological metallic artefacts by quadrupole inductively coupled plasma mass spectrometry (Q-ICPMS) have been developed.
The collection was composed by 24 glandes plumbeae, obtained by different manufacture processes including casting. The lead isotope ratios obtained values by sample dissolution in HNO3 20% did not allow to establish groups having different isotopic compositions, which suggests a probable local production.
Bronze alloys from Fraga dos Corvos were composed by 4 archaeological artefacts and 2 fragments of metallurgical remains. In this case, after acid dissolution with HNO3 20%, the anodic electrochemical separation of Pb from the bronze matrix was performed. The obtained isotope ratio distribution patterns evidenced the existence of two distinct groups, which may indicate exogeneous influences and/or the use of ores with different origin
In the comparative study with Iberian mineralogical deposits, significant correspondences among the Pb isotopic patterns of bronze artefacts and those of mineral deposits from Sierra Morena and Basque-Cantabria basin were observed. Lead artefacts seem to be better associated to deposits from Andalusia-Murcia and Basque-Cantabria, but also from the south of France (Cévennes and Mont-Lozére Massif) and Sardinia.

Durante a Época Romana, o chumbo foi utilizado em larga escala, nomeadamente em tubagens para o sistema hidráulico de cidades e villas, e para fins militares, como nos projécteis de chumbo para funda, designados em latim por glandes plumbeae. Manufacturadas em moldes, caracterizam-se por dimensões reduzidas e de elevada resistência ao ar, tornando-se de difícil visibilidade em voo.
A importância da interpretação da assinatura isotópica do Pb (204Pb, 206Pb, 207Pb e 208Pb) no estudo de proveniências e de rotas comerciais de artefactos metálicos, relaciona-se com o facto de a sua composição isotópica depender da idade geológica do depósito mineral donde foi extraído o metal, uma vez que não ocorre variação das razões isotópicas durante as diversas etapas da produção metalúrgica.
Neste trabalho apresentam-se os resultados obtidos na análise isotópica do chumbo, suplementada pela análise química, de um conjunto de 24 glandes plumbeae de tipologias diversas, descobertas acidentalmente no Alto dos Cacos (Almeirim) e eventualmente associadas ao Exército Romano da antiga Hispânia Ulterior. A análise elementar, não invasiva por EDXRF, permitiu identificar a presença de alguns elementos menores (Fe, Cu, Zn, Ag, Cd, Sn, Sb) com teores variáveis, tendo-se identificado 1 artefacto com teores mais elevados em estanho e 5 em ferro. A composição isotópica do Pb obtida por espectrometria de massa (ICP-QMS) parece indicar a existência de 2 grupos distintos, também associados a diferentes teores de elementos menores, embora independentes das tipologias dos artefactos.

The interpretation of Pb isotopic composition is a very important tool for studies on provenance and trade routes of archaeological metal artefacts. As a matter of fact, in ores Pb have specific isotope ratios that do not change during metallurgical processes remaining identical on produced artefacts. Isotope composition can be directly associated to particular/distinct mineral deposits, being similar whenever submitted to identical geological processes.
The aim of this study was the determination of Pb isotope ratios of a set of bronzes recovered from Fraga dos Corvos (Macedo Cavaleiros) archaeological site, located in Northern Portugal [1]. The studied metallic artefacts have diverse typologies and include 2 bar fragments, 4 fibulae fragments, 1 pendant fragment and 1 cauldron fragment (?). Besides, 2 metallurgical remains (nodule and droplet) were also analyzed.
Previous elemental analysis by micro-EDXRF shows that bronzes have a Sn content varying between 5.1 and 13.9wt% and a Pb content from 1.4 to 6.1wt%, which allowed to select a suitable methodology for lead separation, prior to isotope ratio determinations. In such complex alloys the Pb isotope determinations (204Pb, 206Pb, 207Pb and 208Pb) are influenced by matrix effects that decrease the sensitivity and the reproducibility of the measurements. Analytical procedure followed the previously described in [2] and consisted in electrochemical Pb separation by anodic oxidation in a solution prepared with a small amount of material (~ 3 mg). The determination of Pb isotope ratios was made by ICP-MS with a quadrupole filter and provided the first results of Pb isotopic composition of bronze alloys from the Northern Portuguese territory. Preliminary determinations were obtained with a relative standard deviation below 0.5%.
Pb isotope ratio distributions allowed the identification of different composition patterns indicating probable distinct provenances, although similar isotopic ratios among some artefacts and metallurgical remains pointed out to local metallurgical activities.