EM - IUEM - Tecnologias Laboratoriais em Ciências Forenses
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- Análise não destrutiva de tintas de instrumentos de escrita manual : uma contribuição para a investigação forense de documentosPublication . Eusébio, Daniela Sofia Antunes; Bernardo, Maria Alexandra; Vieira, MárciaEnquadramento: A exigência da preservação de prova em tribunal continua a constituir um desafio à investigação laboratorial, em particular na análise forense de documentos, onde a resposta à discriminação dos utensílios de escrita e datação de documentos é recorrente nos quesitos solicitados. Objetivo: Pretendeu-se desenvolver uma ferramenta pericial, com base em técnicas não destrutivas, que permita a caracterização e discriminação de tintas de canetas comerciais, bem como a identificação de parâmetros de envelhecimento e eventual datação destas tintas. Materiais e Métodos: Foi efetuada uma pesquisa bibliográfica sistematizada para identificar técnicas não destrutivas que permitam a discriminação e datação de tintas e adquiridos corantes e instrumentos de escrita manual comerciais. Procedeu-se ao depósito dos corantes e das tintas em papel corrente e de filtro. Foram igualmente realizadas soluções em metanol e 2-fenoxietanol. As amostras obtidas foram caracterizadas por VSC, colorimetria e espectroscopias UV-Vis, Raman e FORS. Os dados foram tratados com recurso a excel, softwares spectragryph e KNIME Analytics Platform. Resultados e Discussão: Das 51 canetas exploradas por VSC, foram selecionadas 26 de diferentes tipos e modelos, que permitiram a construção de um modelo preditivo com base nos dados da colorimetria apresentando um poder discriminatório entre os 94,545% e 95,385%. Deste subconjunto, apenas 11 (5 azuis e 6 verdes) apresentaram sinal Raman e foram sujeitas a análise por UV-Vis e FORS. As espectroscopias UV-Vis e Raman sugerem a presença do corante solvente azul 38 em 9 das canetas das 11 canetas estudadas, a presença de ftalocianina de cobre (II) em duas delas e residualmente de outros corantes. Com base nos espectros obtidos por FORS e Raman foi igualmente construído um modelo preditivo com um poder discriminatório de 81,818% para FORS e de 72,727% para Raman. Foi ainda possível reconhecer parâmetros de envelhecimento para a tinta de 2 canetas azuis. Conclusão: Este estudo permitiu a construção de uma potencial ferramenta de discriminação de tintas de canetas com recurso a técnicas não destrutivas e a identificação de parâmetros de envelhecimento que poderão no futuro permitir a datação de tintas.
- Dating of writing inks based on the study of volatile compounds / Datação forense de escrita manual através da análise de componentes voláteis de tintasPublication . Leal, Teresa Fernandes Argente; Bernardo, Maria Alexandra; Ferreira, CarlaBackground: One of the major challenges in forensic document analysis is estimating the age of an ink deposition on a manually written document. Objective: The present work aims to develop and optimize a methodology based on the evaporation of volatile compounds over time that can be used to solve real forensic case studies. Materials and methods: Nine pens (5 viscous inks + 4 liquid inks), purchased in commercial areas, were preliminarily analysed, and ink deposition began in September 2016. Initial volatile solvent screening was performed by GC/MS and GC-FID. Samples of the 5 viscous pen inks were further analysed by GC/MS. 20 microdiscs were subjected to n-hexane extraction in the presence of an internal standard (ethyl benzoate) using ultrasound and thermo-agitation, and finally derivatized with 95MSTFA: 5TMCS (TMS). The method was optimized for 2-phenoxyethanol (PE). Subsequently, the aging curve was studied for the black crystal BIC® pen (nr 2). Data were treated with Microsoft Excel® and later analysed on GraphPad Prism 8. Results: The developed method presents, for the (PE-TMS area/IS area) values which were linear between 0.008 and 1.37 (y = 0.0278x-0.0119; R2 = 0.9995), a LOD of 0.026 and a LOQ of 0.104. Through pen nr.2, GC/MS analysis, it was possible to characterize the decay of PE-TMS over time, which reveals a two phase decay behaviour and stabilized after the 33th day, and allowed to detect the presence of PE-TMS until 3 years. Two unknown compounds were also present and allowed to identify three dating time frames for the same ink stroke: (i) between time 0 and ca 33 days; (ii) between time ca 34 and 109 days; (iii) more than ca 109 days. Conclusion: This methodology allowed to characterize the behaviour of PE solvent over time and to establish a relative dating in three time frames.
- Forensic handwriting characterization after rehabilitation intervention in people with Parkinson's disease : pilot studyPublication . Tatarescu, Vlad; Bernardo, Maria Alexandra; Santana, Catarina Godinho; Família, Carlos; Fernandes, CarinaGraphoscopic analysis of handwriting is influenced by various internal and external factors, and individuals with degenerative diseases like Parkinson's face challenges due to limitations in motor abilities, impacting Instrumental Activities of Daily Living (IADL) such as handwriting skills. The absence of encouraging outcomes from interventions in handwriting rehabilitation programs and graphoscopic assessment tools, persists as an ongoing challenge. This pilot study undertook an investigation into the forensi characterization of handwriting in people with Parkinson's Disease (PD). The main goal was to evaluate and compare the effect of 2 rehabilitation programs on handwriting, particularly, regarding 9 static and dynamic features, in individuals with PD. Additionally, this study contributed to the development of a comprehensive protocol, incorporating the most suitable and discriminatory clinical and graphoscopic assessment tools in the context of PD, and to formulate an occupational therapy rehabilitation program focused on enhancing the dexterity and fine motor skills of the upper limbs, crucial for improved performance in Instrumental Activities of Daily Living (IADLs). The pilot clinical trial involved two groups: an intervention group (IG) undergoing traditional physiotherapy and occupational therapy programs (TPRP + OTRP), and a control group (CG) undergoing traditional physiotherapy alone (TPRP). The objective was to characterize and compare handwriting before and after the rehabilitation programs. Participants underwent assessments at the study's commencement and after 12 weeks of intervention. Graphoscopic assessment utilized a Wacom One DTC133W0A tablet and NeuroScript's v6.1 MovAlyzeR software. Clinical assessments included the Jebsen Taylor Hand Function Test, Movement Disorder Society Unified Parkinson Disease Rate Scale, and the Parkinson Disease Questionnaire 8 tests. Results indicated a trend toward reduced symptoms like tremor and bradykinesia, alongside improvements in dynamic features such as average absolute velocity, horizontal size, and average pen pressure. While clinical assessment tools proved suitable, the graphoscopic evaluation fell short compared to existing studies. Nevertheless, the study offered valuable insights for developing a robust handwriting rehabilitation protocol for individuals with PD and an autonomous rehabilitation tool - the Handbook for Handwriting and Occupational Therapy Exercises (H2OTE).