The use of scanning electron microscopy and energy dispersive X-ray spectroscopy in a case of occupational death.

Scanning electron microscopy is a technique that provides high-resolution images at the micro- and nano-scale. The combination of scanning electron microscopy and energy dispersive X-ray spectroscopy analysis is developing fast for application in forensic science. In this work, we report a case of work-related traumatic death of a 50-year-old man. The autopsy showed cranial fractures with cerebral haemorrhage. It was more difficult to understand the accident dynamics because the body had been shifted from the accident site to mask what had really taken place. Scanning electron microscopy/energy dispersive X-ray spectroscopy was used to identify the material of the impacting tool and to establish the possible legal responsibility of the employer. In this study, we demonstrate that scanning electron microscopy/energy dispersive X-ray spectroscopy is a useful forensic tool for the analysis of biological samples. Further, for studying the lacerations on the corpse from doubtful blunt tools, scanning electron microscopy/energy dispersive X-ray spectroscopy can assist in demonstrating that the scene has been falsified, as it was in this case.

Plasmonic photothermal heating of gold nanostars in a real-size container: multiscale modelling and experimental study.

The ability of noble metal nanoparticles (NPs) to convert light into heat has triggered a lot of scientific interest due to the numerous potential applications, including, e.g. photothermal therapy or laser-based nanopatterning. In order for such applications to be practically implemented, the heating behaviour of NPs embedded in their surrounding medium has to be thoroughly understood, and theoretical models capable of predicting this behaviour must be developed. Here we propose a multiscale approach for modelling the photothermal response of a large ensemble of nanoparticles contained within a cm-scale, real-size container. Electromagnetic field, ray tracing and heat transfer simulations are combined in order to model the response of nanostars and nanospheres suspensions contained within a common Eppendorf tube. To validate the model, gold nanostars are then synthesised and characterized by electron microscopy and optical spectroscopy. Laser-induced heating experiments are conducted by irradiating colloid-filled Eppendorf tubes with a 785 nm continuous wave laser and monitoring by a thermographic camera. The experimental results confirm that the proposed model has potential for predicting and analysing the heating efficiency and temperature dynamics upon laser irradiation of plasmonic nanoparticle suspensions in real-scale containers, at cm3 volumes.

Virtopsy versus autopsy in unusual case of asphyxia: case report.

We report the case of a 70-year-old woman found dead in her apartment in the South of Italy in February 2011. The detailed data showed that the victim was affected by familiar-type paranoid schizophrenia. This finding was confirmed by the discovery of antipsychotic and tricyclic antidepressant drugs in the house and the deposition of her psychiatric therapist. Before the autopsy, a multislice computed tomography (MSCT) scanning of the thoracic and facial maxillo-cervical area was performed that has allowed anatomical identification and diagnosis of a mechanical obstruction as the cause of death. The autopsy has showed the presence of materials obstructing the trachea totally. Histological and toxicological investigations were carried out on the victim. The toxicological investigation has shown the presence of metabolites of tricyclic antidepressants and antipsychotics in the blood and urine. The histology showed the presence of foreign-origin materials (starch fibres) inside the pulmonary alveolus. The cause of death was asphyxia due to obstruction by food-origin material. In this case the radiological data have been compared with the autopsy and toxicological and histological data. The comparison of results has shown that MSCT scanning may aid in identification of occlusion and then in determination of the cause of death. In conclusion, MSCT scanning can be proposed in the cases of suspected asphyxia, as the screening procedure of first instance to produce preliminary information useful to rapidly develop the successive autopsy performance.