Is old stuff back? A fatal case of ethyl chloride sniffing

Background: Ethyl chloride (EC) or chloroethane is a colourless halogenated hydrocarbon gas regularly employed as a topical anaesthetic spray for pain-related injuries and muscle spasm in athletes. However, EC became also popular as a street drug in the 1980s. Brief inhalations of EC vapour can result in dizziness, euphoria, confusion, incoordination, hallucinosis, impairment of short-term memory and narcosis. Inhalation of higher doses, usually employed to \u201cget high\u201d, may be related to severe depression of the central nervous system. Indeed, toxicity and deaths have been reported so far. Case presentation: A 40-year-old man was found unresponsive after EC inhalation. EC determination was performed by dynamic headspace gas chromatography coupled to mass spectrometry. EC was detected in the peripheral blood (0.156 g/L), central blood concentration (0.203 g/L) and the lung and brain (19 and 25 mg/kg). EC in the vitreous humour showed a sensitively lower respect to blood (0.018 vs 0.203 g/L). Conclusions: Considering the results of toxicological analyses of investigations on the death scene besides the absence of any signs of trauma, death was attributed to inhalation of ethyl chloride

Forensic applications of micro-computed tomography: a systematic review

Purpose: The aim of this systematic review was to provide a comprehensive overview of micro-CT current applications in forensic pathology, anthropology, odontology, and neonatology. Methods: A bibliographic research on the electronic databases Pubmed and Scopus was conducted in the time frame 01/01/2001–31/12/2021 without any language restrictions and applying the following free-text search strategy: “(micro-computed tomography OR micro-CT) AND (forensic OR legal)”. The following inclusion criteria were used: (A) English language; (B) Application of micro-CT to biological and/or non-biological materials to address at least one forensic issue (e.g., age estimation, identification of post-mortem interval). The papers selected by three independent investigators have been then classified according to the investigated materials. Results: The bibliographic search provided 651 records, duplicates excluded. After screening for title and/or abstracts, according to criteria A and B, 157 full-text papers were evaluated for eligibility. Ninety-three papers, mostly (64) published between 2017 and 2021, were included; considering that two papers investigated several materials, an overall amount of 99 classifiable items was counted when referring to the materials investigated. It emerged that bones and cartilages (54.55%), followed by teeth (13.13%), were the most frequently analyzed materials. Moreover, micro-CT allowed the collection of structural, qualitative and/or quantitative information also for soft tissues, fetuses, insects, and foreign materials. Conclusion: Forensic applications of micro-CT progressively increased in the last 5 years with very promising results. According to this evidence, we might expect in the near future a shift of its use from research purposes to clinical forensic cases

Metabolomics and lipid profile analysis of Coccomyxa melkonianii SCCA 048

With an unsupervised GC–MS metabolomics approach, polar metabolite changes of the microalgae Coccomyxa melkonianii SCCA 048 grown under standard conditions for seven weeks were studied. C. melkonianii was sampled at the Rio Irvi River, in the mining site of Montevecchio-Ingurtosu (Sardinia, Italy), which is severely contaminated by heavy metals and shows high concentrations of sulfates. The partial-least-square (PLS) analysis of the GC–MS data indicated that growth of C. melkonianii was characterized by an increase of the levels of threonic acid, myo-inositol, malic acid, and fumaric acid. Furthermore, at the sixth week of exponential phase the lipid fingerprint of C. melkonianii was studied by LC-QTOF-MS. C. melkonianii lipid extract characterized through an iterative MS/MS analysis showed the following percent levels: 61.34 ± 0.60% for triacylglycerols (TAG); 11.55 ± 0.09% for diacylglyceryltrimethyl homoserines (DGTS), 11.34 ± 0.10% for sulfoquinovosyldiacylglycerols (SQDG) and, 5.29 ± 0.04% for lysodiacylglyceryltrimethyl homoserines (LDGTS). Noteworthy, we were able to annotate different fatty acid ester of hydroxyl fatty acid, such as FAHFA (18:1_20:3), FAHFA (18:2_20:4), FAHFA (18:0_20:2), and FAHFA (18:1_18:0), with relevant biological activity. These approaches can be useful to study the biochemistry of this extremophile algae in the view of its potential exploitation in the phycoremediation of polluted mining areas

Valproic acid determination by liquid chromatography coupled to mass spectrometry (LC–MS/MS) in whole blood for forensic purposes

Valproic acid (VPA) is a well-known drug prescribed as anti-epileptic. It has a narrow therapeutic range and shows great individual differences in pharmacodynamics and pharmacokinetics. Consequently, the therapeutical drug monitoring (TDM) in patient's plasma is of crucial importance. Liquid chromatography coupled to mass spectrometry (LC–MS/MS) has gained importance in TDM applications for its features of sensitivity, selectivity and rapidity. However, in case of VPA, the LC–MS/MS selectivity could be hampered by the lack of a sufficient number of multiple reaction monitoring (MRM) transitions describing the molecule. In fact, the product ion scan of deprotonated molecules of VPA does not produce any ion and thus most LC–MS/MS methods are based on the detection of the unique MRM transition m/z 143➔143. In this way, the advantages of selectivity in LC–MS cannot be effectively exploited. In the present method, stable analyte adducts were exploited for the determination of VPA in blood. An Acquity HSS C18 column and mobile phases consisting of 5-mM ammonium formate and acetonitrile both added 0.1% formic acid were used. Source worked in negative acquisition mode and parameters were optimized to increase the adduct (m/z 189) and dimer (m/z 287) stability, and their fragmentation were used to increase the selectivity of MRM detection. The method has been validated according to the toxicological forensic guidelines and successfully applied to 10 real blood samples. Finally, the present method showed suitable for the rapid LC–MS/MS detection of VPA in whole blood, demonstrating the possibility to increase specificity by exploiting stable in-source adducts. This should be considered of utmost importance in the case of forensic applications

Digital Signal Processing procedures of Ultrasonic and 3-D Terrestrial Laser Scanner data in the diagnostics of monumental structures

A new non-destructive methodology based on the experimental application of integrated use of 3-D terrestrial laser scanning (3-D TLS) and ultrasonic techniques in the range (54-82 kHz) in evaluating the quality of stone building materials in monumental structures has provided satisfactory results. In this paper our target is to evaluate the state of conservation of the previously described materials by correlating the ultrasonic measurement results with the reflectivity of the reflected 3-D laser scanner beam pulse transmitted to the target of an investigated surface. Ultrasonic methods are very effective in detecting the elastic characteristics of stone materials and thus their mechanical behaviour even though data interpretation is very complex as elastic wave velocity depends on moisture, heterogeneity, porosity and other physical properties. The study of the propagation of the longitudinal ultrasonic pulses is improved from the digital signal processing which allows to obtain information from the wavetrains. Therefore accurate ultrasonic analyses based not only on longitudinal pulse velocity analysis but also on frequency spectra and cross-spectra analyses allowed to improve the results of the diagnostics in assessing and monitoring the status of the investigated materials. In a 3D Terrestrial Laser Scanner the travelling time of coherent light laser pulse is converted into the distance between the instrument and the investigated object. The result of a laser scanning survey is a very dense cloud of points whose positions are known in a reference frame located in an arbitrary point inside the instrument. For each point of the surveyed target surface, the X, Y, Z coordinates and the reflectivity value are acquired and recorded, providing the area coverage necessary for the 3-D reconstruction and characterisation of the surveyed structure. In general an interesting correlation between the spectral changes observed in the analysis of ultrasonic signals acquired in different sectors (damaged and intact) of the investigated monumental structure and those observed in the analysis of the 3-D TLS reflectivity data acquired in the same sectors was found. The changes in spectral frequency composition of the ultrasonic and 3-D TLS data seem to be related to changes in stone material properties, but the relationship between frequency composition and rock-properties is not early as definitive. Taking these results into account further digital processing procedures and analyses on the ultrasonic and 3-D TLS data and their comparison with petrophysical aspects are now scheduled

Application of acoustic techniques in the evaluation of heterogeneous building materials

In this paper, we present the results of an application of in situ non-destructive acoustic techniques to analyse the state of preservation of a colonnade of an ancient church in the Central Sardinia (Italy). In particular, low frequency ultrasonic tests and seismic longitudinal wave transmission tomography (SLWTT) techniques were applied on the columns of the church in order to provide information on their state of preservation and to detect possible defects, such as zones of weakness, damages and cracks in its inner parts that cannot be visually examined. In order to improve the velocity input model for the SLWTT, a new experimental procedure based on the calculation of the cross-correlation function was proposed and usefully applied. An estimate of the accuracy of the longitudinal wave velocity measurements by SLWTT methods was carried out by application of a standard error analysis based on the law of propagation of uncertainty. Based on the results obtained with the ultrasonic and seismic investigations, we located microcores that confirmed information from the above non invasive investigations

Homicide or suicide? A probabilistic approach for the evaluation of the manner of death in sharp force fatalities

The role of forensic science can be defined as providing relevant opinions to assist investigators and courts of law in answering questions. The Likelihood Ratio (LR) provides a quantitative and logical approach to communicating the strength of expert evidence. We reviewed existing forensic literature on sharp force fatalities, focusing on studies reporting the manner of death and the frequency of some characteristics that are traditionally assessed. Four studies were included, resulting in a database of 173 suicides and 354 homicides. The LR of each of the characteristic under both hypotheses (suicide and homicide) was obtained. Subsequently, the LR was computed in six fatalities with known manner of death, three suicides and three homicides, by multiplying the corresponding LR of each individual characteristic. LR ranged from 115 to 140,250 in suicidal cases and from 9 to 2728 in homicidal cases. Compared to other fields of forensic science where LR is used extensively, the values obtained in our cases of sharp force fatalities is low. However, in forensic pathology there is evidence that is outside the expert's opinion, and it is for the trier of fact, such as the judge or jury, to draw conclusions. Nevertheless, the LR serves as a tool for interpreting and weighing evidence while maintaining the distinct roles of the trier of fact and the expert. To comprehensively apply the LR in the field of sharp force deaths, it will be necessary to standardize the methodology of investigation and data collection in descriptive studies