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Dyke, J. M., G. Levita, A. Morris, J. S. Ogden, A. A. Dias, M. Algarra, J. P. Santos, M. L. Costa, P. Rodrigues, M. M. Andrade, and M. T. Barros. "Contrasting Behavior in Azide Pyrolyses: An Investigation of the Thermal Decompositions of Methyl Azidoformate, Ethyl Azidoformate and 2-Azido-N, N-dimethylacetamide by Ultraviolet Photoelectron Spectroscopy and Matrix Isolation Infrared Spectroscopy." Chemistry - A European Journal 11 (2005): 1665-1676. Abstract
The thermal decompositions of methyl azidoformate (N3COOMe), ethyl azidoformate (N3COOEt) and 2-azido-N,N-dimethylacetamide (N3CH2CONMe2) have been studied by matrix isolation infrared spectroscopy and real-time ultraviolet photoelectron spectroscopy. N2 appears as an initial pyrolysis product in all systems, and the principal interest lies in the fate of the accompanying organic fragment. For methyl azidoformate, four accompanying products were observed: HNCO, H2CO, CH2NH and CO2, and these are believed to arise as a result of two competing decomposition routes of a four-membered cyclic intermediate. Ethyl azidoformate pyrolysis yields four corresponding products: HNCO, MeCHO, MeCHNH and CO2, together with the five-membered-ring compound 2-oxazolidone. In contrast, the initial pyrolysis of 2-azido-N,N-dimethyl acetamide, yields the novel imine intermediate Me2NCOCHNH, which subsequently decomposes into dimethyl formamide (HCONMe2), CO, Me2NH and HCN. This intermediate was detected by matrix isolation IR spectroscopy, and its identity confirmed both by a molecular orbital calculation of its IR spectrum, and by the temperature dependence and distribution of products in the PES and IR studies. Mechanisms are proposed for the formation and decomposition of all the products observed in these three systems, based on the experimental evidence and the results of supporting molecular orbital calculations.
Dyke, J. M., G. Levita, A. Morris, J. S. Ogden, A. A. Dias, M. Algarra, J. P. Santos, M. L. Costa, P. Rodrigues, M. M. Andrade, and M. T. Barros. "Contrasting Behavior in Azide Pyrolyses: An Investigation of the Thermal Decompositions of Methyl Azidoformate, Ethyl Azidoformate and 2-Azido-N, N-dimethylacetamide by Ultraviolet Photoelectron Spectroscopy and Matrix Isolation Infrared Spectroscopy." Chemistry - A European Journal 11 (2005): 1665-1676. Abstract

The thermal decompositions of methyl azidoformate (N3COOMe), ethyl azidoformate (N3COOEt) and 2-azido-N,N-dimethylacetamide (N3CH2CONMe2) have been studied by matrix isolation infrared spectroscopy and real-time ultraviolet photoelectron spectroscopy. N2 appears as an initial pyrolysis product in all systems, and the principal interest lies in the fate of the accompanying organic fragment. For methyl azidoformate, four accompanying products were observed: HNCO, H2CO, CH2NH and CO2, and these are believed to arise as a result of two competing decomposition routes of a four-membered cyclic intermediate. Ethyl azidoformate pyrolysis yields four corresponding products: HNCO, MeCHO, MeCHNH and CO2, together with the five-membered-ring compound 2-oxazolidone. In contrast, the initial pyrolysis of 2-azido-N,N-dimethyl acetamide, yields the novel imine intermediate Me2NCOCHNH, which subsequently decomposes into dimethyl formamide (HCONMe2), CO, Me2NH and HCN. This intermediate was detected by matrix isolation IR spectroscopy, and its identity confirmed both by a molecular orbital calculation of its IR spectrum, and by the temperature dependence and distribution of products in the PES and IR studies. Mechanisms are proposed for the formation and decomposition of all the products observed in these three systems, based on the experimental evidence and the results of supporting molecular orbital calculations.

Wain, Alison, Diogo Castro, {Maria Fernanda} Rollo, Frederico Nogueira, Gon{\c c}alo Santos, {Maria Gra{\c da c}a} Filipe, Isabel Tissot, {Jorge Miguel} Sampaio, {José Paulo} Santos, Manuel Lemos, Marta Manso, Matthias Tissot, Mauro Guerra, Miles Oglethorpe, Pedro Amaro, Pedro Pedroso, Rui Silva, Sofia Pessanha, and {Tiago A. N. } Silva. Cultura Material, Cultura Científica: Património Industrial para o Futuro. Portugal: Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2021. Abstract

Material, Culture, Scientific Culture: Industrial Heritage for the Future

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Rahangdale, H. V., M. Guerra, P. K. Das, S. De, J. P. Santos, D. Mitra, and S. Saha. "Determination of subshell-resolved <span class="aps-inline-formula"><math><mi>L</mi></math></span>-shell-ionization cross sections of gold induced by 15–40-keV electrons." Physical Review A 89 (2014): 052708. AbstractWebsite
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Rahangdale, H. V., M. Guerra, P. K. Das, S. De, J. P. Santos, D. Mitra, and S. Saha. "Determination of subshell-resolved <span class="aps-inline-formula"><math><mi>L</mi></math></span>-shell-ionization cross sections of gold induced by 15–40-keV electrons." Physical Review A 89 (2014): 052708. AbstractWebsite
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Ramos, I., I. M. Pataco, M. P. Mourinho, F. Lidon, F. Reboredo, M. F. Pessoa, M. L. Carvalho, J. P. Santos, and M. Guerra. "Elemental mapping of biofortified wheat grains using micro X-ray fluorescence." Spectrochimica Acta Part B: Atomic Spectroscopy 120 (2016): 30-36. AbstractWebsite

Spectrochimica Acta Part B: Atomic Spectroscopy, 120 (2016) 30-36. doi:10.1016/j.sab.2016.03.014

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Ito, Y., T. Tochio, H. Ohashi, M. Yamashita, S. Fukushima, M. Polasik, K. Słabkowska, Ł. Syrocki, E. Szymańska, J. Rzadkiewicz, P. Indelicato, J. P. Marques, M. C. Martins, J. P. Santos, and F. Parente. "Kα1,2x-ray linewidths, asymmetry indices, and [KM]shake probabilities in elements Ca to Ge and comparison with theory for Ca, Ti, and Ge." Physical Review A 94 (2016): 042506-11. AbstractWebsite
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Pohl, Randolf, François Nez, Luis M. P. Fernandes, Marwan Abdou Ahmed, Fernando D. Amaro, Pedro Amaro, François Biraben, João M. R. Cardoso, Daniel S. Covita, Andreas Dax, Satish Dhawan, Marc Diepold, Beatrice Franke, Sandrine Galtier, Adolf Giesen, Andrea L. Gouvea, Johannes Götzfried, Thomas Graf, Theodor W. Hänsch, Malte Hildebrandt, Paul Indelicato, Lucile Julien, Klaus Kirch, Andreas Knecht, Paul Knowles, Franz Kottmann, Julian J. Krauth, Eric-Olivier Le Bigot, Yi-Wei Liu, José A. M. Lopes, Livia Ludhova, Jorge Machado, Cristina M. B. Monteiro, Françoise Mulhauser, Tobias Nebel, Paul Rabinowitz, Joaquim M. F. dos Santos, Jose Paulo Santos, Lukas A. Schaller, Karsten Schuhmann, Catherine Schwob, Csilla I. Szabo, David Taqqu, João F. C. A. Veloso, Andreas Voss, Birgit Weichelt, and Aldo Antognini. "Laser Spectroscopy of Muonic Atoms and Ions." In Proceedings of the 12th International Conference on Low Energy Antiproton Physics (LEAP2016), 1-12. Journal of the Physical Society of Japan, 2017. Abstract
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Guimarães, D., M. L. Carvalho, M. Becker, A. von Bohlen, V. Geraldes, I. Rocha, and J. P. Santos. "Lead concentration in feces and urine of exposed rats by X-ray Fluorescence and Electrothermal Atomic Absorption Spectrometry." X-Ray Spectrometry In press (2011). Abstract
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Guimarães, D., M. L. Carvalho, M. Becker, A. von Bohlen, V. Geraldes, I. Rocha, and J. P. Santos. "Lead concentration in feces and urine of exposed rats by x-ray fluorescence and electrothermal atomic absorption spectrometry." X-Ray Spectrom. 41 (2012): 80. Abstract

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Guimarães, D., M. L. Carvalho, M. Becker, A. von Bohlen, V. Geraldes, I. Rocha, and J. P. Santos. "Lead concentration in feces and urine of exposed rats by x-ray fluorescence and electrothermal atomic absorption spectrometry." X-Ray Spectrometry 41 (2012): 80. AbstractWebsite

Measurements made in feces and urine of Wistar rats exposed to lead acetate (n = 20) in drinking water since the fetal period were compared with those obtained from a control group (n = 20) in order to assess the age influence on Pb excretion. The measurements were made in different collections of rats aging between 1 and 11 months. To determine the Pb content of the samples, total reflection X-ray fluorescence (TXRF) and electrothermal atomic absorption spectrometry (ETAAS) were used for the urine samples and energy dispersive X-ray fluorescence (EDXRF) was used for the feces.The results show high concentrations of Pb being eliminated from the organism by urine and feces in contaminated rats. Values vary from (600`140)mgl1 to (5 460`115)mgl1 in urine and from (4 500`300)mgg1 to (11 400`3 300)mgg1 in dry feces. The control rats show, in general, low lead concentrations or below detection limits. The fecal/urinary ratio was studied. It was shown to be about three to four orders of magnitude and positively correlated with time. It was verified in feces and urine that excretion decreases with the animal age and that this decrease is made by different levels of excretion. The excretions of Pb in urine and in feces are positively correlated.A good agreement was found between the results obtained with TXRF and ETAAS for urine samples. This work also stresses the suitability of these techniques in the study of Pb intoxication.

Guimarães, Diana, Maria Luisa Carvalho, Vera Geraldes, Isabel Rocha, Luís Cerqueira Alves, and Jose Paulo Santos. "Lead in liver and kidney of exposed rats: Aging accumulation study." J. Trace Elem. Med Biol. 26 (2012): 285. AbstractWebsite

The concentration of lead in liver and kidneys of Wistar rats, fed with lead since fetal period in relation to their age and to a control group, was determined. A group of rats was exposed to lead acetate (n=30) in drinking water and the other group was exposed to normal water (n=20). Samples were collected from rats aging between 1 and 11 months and were analyzed by Energy Dispersive X-ray Fluorescence (EDXRF) without any chemical preparation. The EDXRF results were assessed by the PIXE (Proton Induced X-ray Emission) technique. The formaldehyde used to preserve the samples was also analyzed by ETAAS (Electro-Thermal Atomic Absorption Spectrometry) in order to verify if there was any loss of lead from the samples to the formaldehyde. We found that the loss was not significant (<2%). Concerning the mean values of the lead concentration measured in the contaminated soft tissues, in liver they range from 6 to 22μgg(-1), and in kidneys from 44 to 79μgg(-1). The control rats show, in general, values below the EDXRF detection limit (2μgg(-1)). The ratio kidney/liver ranges from 2 to 10 and is strongly positively correlated with the age of the animals. A Spearman correlation matrix to investigate the correlation between elemental concentrations and the dependence of these concentrations with age showed that there is a strong positive correlation with age for lead in the liver but not in the kidney. The correlation matrix showed also that the concentration of lead in these two soft tissues is not correlated. The lead accumulation in liver is made by different plateaus that strongly decrease with age. It was verified the existence of two levels of accumulation in kidney, not very highlighted, which might be indicative of a maximum accumulation level for lead in kidney.

Guimarães, Diana, Maria Luisa Carvalho, Vera Geraldes, Isabel Rocha, Luís Cerqueira Alves, and Jose Paulo Santos. "Lead in liver and kidney of exposed rats: Aging accumulation study." Journal of Trace Elements in Medicine and Biology 26 (2012): 285. AbstractWebsite

The concentration of lead in liver and kidneys of Wistar rats, fed with lead since fetal period in relation to their age and to a control group, was determined. A group of rats was exposed to lead acetate (n=30) in drinking water and the other group was exposed to normal water (n=20). Samples were collected from rats aging between 1 and 11 months and were analyzed by Energy Dispersive X-ray Fluorescence (EDXRF) without any chemical preparation. The EDXRF results were assessed by the PIXE (Proton Induced X-ray Emission) technique. The formaldehyde used to preserve the samples was also analyzed by ETAAS (Electro-Thermal Atomic Absorption Spectrometry) in order to verify if there was any loss of lead from the samples to the formaldehyde. We found that the loss was not significant (<2%). Concerning the mean values of the lead concentration measured in the contaminated soft tissues, in liver they range from 6 to 22μgg(-1), and in kidneys from 44 to 79μgg(-1). The control rats show, in general, values below the EDXRF detection limit (2μgg(-1)). The ratio kidney/liver ranges from 2 to 10 and is strongly positively correlated with the age of the animals. A Spearman correlation matrix to investigate the correlation between elemental concentrations and the dependence of these concentrations with age showed that there is a strong positive correlation with age for lead in the liver but not in the kidney. The correlation matrix showed also that the concentration of lead in these two soft tissues is not correlated. The lead accumulation in liver is made by different plateaus that strongly decrease with age. It was verified the existence of two levels of accumulation in kidney, not very highlighted, which might be indicative of a maximum accumulation level for lead in kidney.

Cardoso, P., T. C. Mateus, G. Velu, R. P. Singh, J. P. Santos, M. L. Carvalho, V. M. Louren{\c c}o, F. Lidon, F. Reboredo, and M. Guerra. "Localization and distribution of Zn and Fe in grains of biofortified bread wheat lines through micro- and triaxial-X-ray fluorescence spectrometry." Spectrochim. Acta Part B 141 (2018): 70-79. Abstract

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Reboredo, {Fernando Henrique}, A. Barbosa, {Maria Manuela} Silva, {Maria Luisa} Carvalho, {José Paulo} Santos, {Maria Fernanda} Pessoa, Fernando Lidon, {José C. } Ramalho, and Mauro Guerra. "Mineral Content of Food Supplements of Plant Origin, by Energy Dispersive X-ray Fluorescence: A Risk Assessment." Exposure and Health 12 (2020): 917-927. Abstract

The aim of this study is to evaluate the elemental composition of six food supplements of plant origin, commonly sold in the Portuguese market, by energy dispersive X-ray fluorescence. The presence of arsenic in all the Maca, Ashwagandha, Camu-Camu and Hemp protein samples (except the generic form) is a reason of concern due to the long-term effects of As mainly in its inorganic form. Thus, great caution must be taken on some food supplements, particularly the cases of Moringa from Egypt and Yellow/Xpresso Maca, whose inorganic As concentrations are in line with the upper bound concentration for the 95th dietary exposure according to the European Food Safety Authority which is 0.64 μg/kg bw/day. In what regards Hemp protein, if the supplier’s daily intake recommendation (30 g) is followed, values as high as 1.75 μg/kg bw/day of inorganic As will be consumed, which are dangerously above the upper bound. In this case this specific supplement lot should be removed from the market. Also the consumption of Hemp protein leads to a daily intake of Mn above the Daily Reference Intake (DRI) and Adequate Intakes (AIs) for adults. The contamination of Goji berries by Pb is a reason for concern—organic berries contained 11.3 μg/g while berries derived from conventional agriculture 11.6 μg/g, leading to daily intake doses of 315.3 μg and 324.8 μg, respectively, if the recommended daily intake of 28 g is followed. Our findings point out to an inadequacy of the recommended intakes by the supplier vis a vis the concentrations observed, greatly increasing the risk for public health.

Lopes, A., A. Gabriel, J. Machado, P. Ribeiro, R. Gomes, Jo M. P. o Coelho, C. O. Silva, C. P. Reis, J. P. Santos, and P. Vieira. "Multiple Source Phototherapy in Breast Cancer: A Viability Study." In 9th International Conference on Biomedical Electronics and Devices, 247-250. SCITEPRESS - Science and and Technology Publications, 2016. Abstract
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Togawa, M., S. Kühn, C. Shah, P. Amaro, R. Steinbrügge, J. Stierhof, N. Hell, M. Rosner, K. Fujii, M. Bissinger, R. Ballhausen, M. Hoesch, J. Seltmann, S. Park, F. Grilo, F. S. Porter, J. P. Santos, M. Chung, T. Stöhlker, J. Wilms, T. Pfeifer, G. V. Brown, M. A. Leutenegger, S. Bernitt, and Crespo J. R. López-Urrutia. "Observation of strong two-electron–one-photon transitions in few-electron ions." Physical Review A 102 (2020). AbstractWebsite
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Indelicato, P., G. C. Rodrigues, E. Lindroth, M. A. Ourdane, F. Parente, J. P. Santos, P. Patté, and J. Bieron. "Relativistic and many-body effects on total binding energies of Cesium and other highly-charged ion." Physica Scripta T92 (2001): 327. Abstract

The determination of atomic masses from highly ionized atoms using Penning Traps requires precise values for electronic binding energies. In the present work, binding energies of several ions (from several elements) are calculated in the framework of two relativistic many-body methods: Relativistic Many-Body Perturbation Theory (RMBPT) and Multi-Configuration Dirac– Fock (MCDF). The ions studied in this work are: Cl (He and Li-like), Se (F and Ne-like), Cs (He, Be, Ne, Al, Cl, Ar, K, Kr, Xe-like and neutral Cs), Hg, Pb and U (Br and Kr-like). Some of them are presented in this paper. Cesium has been treated in more details, allowing for a systematic comparison between MCDF and RMBPT methods. The Cs ions binding energies allow for the determination of atomic Cs mass, which can be used in a QED-independent fine structure constant determination.

Indelicato, P., E. Lindroth, T. Beier, J. Bieron, A. M. Costa, I. Lindgren, J. P. Marques, A. M. Martenson-Pendrill, M. C. Martins, M. A. Ourdane, F. Parente, P. Patté, G. C. Rodrigues, S. Salomonson, and J. P. Santos. "Relativistic Calculations for Trapped Ions." Hyperfine Interactions 132 (2001): 347-361. AbstractWebsite

We present recent results in the field of total binding energy calculations, Land&shchcy; factors, quantum electrodynamics corrections and lifetime that are of interest for ion traps and ion sources. We describe in detail MCDF and RMBPT calculation of ionic binding energies, which are needed for the determination of atomic masses from highly charged ion measurements. We also show new results concerning Land&shchcy; factor in 3-electron ions. Finally we describe how relativistic calculations can help understand the physics of heavy ion production ion sources.

Santos, J. P., G. C. Rodrigues, J. P. Marques, F. Parente, J. P. Desclaux, and P. Indelicato. "Relativistic correlation correction to the binding energies of the ground configuration of beryllium-like, neon-like, magnesium-like and argon-like ions." The European Physical Journal D 37 (2006): 201-207. AbstractWebsite
Total electronic correlation corrections to the binding energies of the isoelectronic series of beryllium, neon, magnesium and argon, are calculated in the framework of relativistic multiconfiguration Dirac-Fock method. Convergence of the correlation energies is studied as the active set of orbitals is increased. The Breit interaction is treated fully self-consistently. The final results can be used in the accurately determination of atomic masses from highly charged ions data obtained in Penning-trap experiments.
Santos, J. P., G. C. Rodrigues, J. P. Marques, F. Parente, J. P. Desclaux, and P. Indelicato. "Relativistic correlation correction to the binding energies of the ground configuration of beryllium-like, neon-like, magnesium-like and argon-like ions." The European Physical Journal D 37 (2006): 201-207. AbstractWebsite

Total electronic correlation corrections to the binding energies of the isoelectronic series of beryllium, neon, magnesium and argon, are calculated in the framework of relativistic multiconfiguration Dirac-Fock method. Convergence of the correlation energies is studied as the active set of orbitals is increased. The Breit interaction is treated fully self-consistently. The final results can be used in the accurately determination of atomic masses from highly charged ions data obtained in Penning-trap experiments.

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Rahangdale, H. V., D. Mitra, P. K. Das, S. De, M. Guerra, J. P. Santos, and S. Saha. "Spectroscopic investigations of L-shell ionization in heavy elements by electron impact." Journal of Quantitative Spectroscopy and Radiative Transfer 174 (2016): 79-87. AbstractWebsite

Journal of Quantitative Spectroscopy and Radiative Transfer, 174 + (2016) 79-87. doi:10.1016/j.jqsrt.2016.01.026

Ito, Y., T. Tochio, M. Yamashita, S. Fukushima, A. M. Vlaicu, J. P. Marques, J. M. Sampaio, M. Guerra, J. P. Santos, Ł. Syrocki, K. Słabkowska, E. WÈ©der, M. Polasik, J. Rzadkiewicz, P. Indelicato, Y. Ménesguen, M.-Ch. Lépy, and F. Parente. "Structure of K$\upalpha$1,2- and K$\upbeta$1,3-emission x-ray spectra for Se, Y, and Zr." Physical Review A 102 (2020). AbstractWebsite
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Guimarães, D., M. L. Carvalho, V. Geraldes, I. Rocha, and J. P. Santos. "Study of lead accumulation in bones of Wistar rats by X-ray fluorescence analysis: aging effect." Metallomics In Press (2011): DOI: 10.1039/c1mt00149c. AbstractWebsite

The accumulation of lead in several bones of Wistar rats with time was determined and comparedQ3 for the different types of bones. Two groups were studied: a control group (n = 20), not exposedto lead and a contaminated group (n = 30), exposed to lead from birth, first indirectly throughmother’s milk, and then directly through a diet containing lead acetate in drinking water (0.2%).Rats age ranged from 1 to 11 months, with approximately 1 month intervals and each of thecollections had 3 contaminated rats and 2 control rats. Iliac, femur, tibia–fibula and skull havebeen analysed by energy dispersive X-ray fluorescence technique (EDXRF). Samples offormaldehyde used to preserve the bone tissues were also analysed by Electrothermal AtomicAbsorption (ETAAS), showing that there was no significant loss of lead from the tissue to thepreservative. The bones mean lead concentration of exposed rats range from 100 to 300 mg g 1while control rats never exceeded 10 mg g 1. Mean bone lead concentrations were compared andthe concentrations were higher in iliac, femur and tibia–fibula and after that skull. However, ofall the concentrations in the different collections, only those in the skull were statisticallyQ4 significantly different (p o 0.05) from the other types of bones. Analysis of a radar chart alsoallowed us to say that these differences tend to diminish with age. The Spearman correlation testapplied to mean lead concentrations showed strong and very strong positive correlations betweenall different types of bones. This test also showed that mean lead concentrations in bones arenegatively correlated with the age of the animals. This correlation is strong in iliac and femur andvery strong in tibia–fibula and skull. It was also shown that the decrease of lead accumulationwith age is made by three plateaus of accumulation,