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About

About

I was born in Lisbon, Portugal, in 1983 and graduated from Faculdade de Ciências e Tecnologia Universidade Nova de Lisboa (FCT-UNL) in Physics Engineering in 2006. My undergraduate research consisted in developing and assembly of a specialized X-ray fluorescence spectrometer. This work lead to a Master in Physics Engineering (FCT-UNL, 2007) and a PhD in Atomic Physics (FCT-UNL, 2011) entitled: “Measurement of lead concentration in biological tissues by atomic spectroscopy techniques”.

In 2012, I moved to Albany (New York, USA) as a Postdoc in Analytical Chemistry, to work at the Trace Elements group, Wadsworth Center New York State Department of Health. In the same year I transitioned to a Research Scientist position and became supervisor of the X-ray lab. Here I participated in multiple projects concerning biomonitoring and environmental analysis of trace elements in several matrices (food, cosmetics, medicines, consumer products, human tissues and body fluids) using analytical techniques based on atomic spectrometry, including synchrotron radiation at the Cornell University. I also spent 2 years as a Research Assistant Professor at the University at Albany, State University of New York – School of Public Health, Department of Environmental Health Sciences.

In 2016 I decided to shift my research focus from atomic to nuclear radiation.  I moved to Porto, Portugal, and I am currently working at INESC-TEC developing fiber optic sensors to detect the presence of Radon, a radioactive element, in marine environments.

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Details

Details

  • Name

    Diana Filipa Guimarães
  • Cluster

    Computer Science
  • Role

    Researcher
  • Since

    07th November 2016
001
Publications

2016

Quantitative determinations and imaging in different structures of buried human bones from the XVIII-XIXth centuries by energy dispersive X-ray fluorescence - Postmortem evaluation

Authors
Guimaraes, D; Dias, AA; Carvalho, M; Carvalho, ML; Santos, JP; Henriques, FR; Curate, F; Pessanha, S;

Publication
TALANTA

Abstract
In this work, a non-commercial triaxial geometry energy dispersive X-ray Fluorescence (EDXRF) setup and a benchtop mu-XRF system were used to identify postmortem contamination in buried bones. For two of the individuals, unusually high concentrations of Cu and Pb, but also Zn (in one individual) were observed. The pigments of the burial shroud coverings have been identified as the source of contamination. Accurate and precise quantitative results were obtained by nondestructive process using fundamental parameters method taking into account the matrix absorption effects. A total of 30 bones from 13 individuals, buried between the mid-XVlllth to early XIXth centuries, were analyzed to study the elemental composition and elemental distribution. The bones were collected from a church in Almada (Portugal), called Ermida do Espirito Santo, located near the Tagus River and at the sea neighbourhood. The triaxial geometry setup was used to quantify Ca, Fe, Cu, Zn, Br, Sr and Pb of powder pressed bone pellets (n=9 for each bone). Cluster analysis was performed considering the elemental concentrations for the different bones. There was a clear association between some bones regarding Fe, Cu, Zn, Br and Pb content but not a categorization between cortical and trabecular bones. The elemental distribution of Cu, Zn and Pb were assessed by the benchtop p.-analysis, the M4 Tornado, based on a polycapillary system which provides multi-elemental 2D maps. The results showed that contamination was mostly on the surface of the bone confirming that it was related to the burial shroud covering the individuals.

2015

Radioisotope-based XRF instrumentation for determination of lead in paint: an assessment of the current accuracy and reliability of portable analyzers used in New York State

Authors
Guimarães, D; Cleaver, TM; Martin, SF; Parsons, PJ;

Publication
Anal. Methods

Abstract

2015

Evaluation of portable XRF instrumentation for assessing potential environmental exposure to toxic elements

Authors
McIntosh, KG; Guimarães, D; Cusack, MJ; Vershinin, A; Chen, Z; Yang, K; Parsons, PJ;

Publication
International Journal of Environmental Analytical Chemistry

Abstract

2014

Analytical evidence of heterogeneous lead accumulation in the hypothalamic defence area and nucleus tractus solitarius

Authors
Guimaraes, D; Santos, JP; Carvalho, ML; Diniz, MS; House, B; Miller, VM;

Publication
NEUROTOXICOLOGY

Abstract
Lead is a potent toxicant associated with adverse cardiovascular effects and hypertension in children. Yet, few studies have determined if autonomic dysfunction associated with lead exposure involves brain regions which regulate autonomic responses. Central autonomic nuclei such as the nucleus tractus solitarius (NTS) and hypothalamic defence area (HDA) may be particularly sensitive to lead infiltration because they are adjacent to ventricles and areas with semi-permeable blood-brain-barriers. To understand if autonomic nuclei are sensitive to lead accumulation Wistar rats were exposed to lead from the gestational period and lead levels were quantified in brain regions that regulate arterial pressure: the NTS and the HDA. Energy dispersive X-ray fluorescence (EDXRF) was used to quantify total brain lead levels and revealed no differences between exposed and control tissues; measured values were close to the detection limit (2 mu g/g). Electrothermal atomic absorption spectrometry (ETAAS) was also used, which has a greater sensitivity, to quantify lead. There was similar to 2.1 mu g/g lead in the NTS and similar to 3.1 mu g/g lead in the HDA of exposed rats, and no lead in the control rats. There were greater lead levels in the HDA (similar to 50%) as compared with the NTS. Pathology studies revealed more prominent lead granules in the HDA as compared with the NTS. Increased microglia and astrocyte activation was also noted in the NTS of lead exposed rats as compared with the HDA. Regional differences in neuro-inflammatory responses likely contribute to heterogeneous lead accumulation, with enhanced clearance of lead in the NTS. Future studies will resolve the mechanisms underpinning tissue-specific lead accumulation.