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The principal site for gaseous exchange within the lung is the alveolar space, which is bathed in alipid‐protein blend called pulmonary surfactant. This material is the initial contacting site for orallyinhaled products and environmental toxins. Using the lung biosimulator, this study investigatesthe influence of cannabis smoke on the activity of the lung surfactant replacement product,Curosurf. Initially, 50‐mg cannabis material was pyrolysed and the smoke collected. Cannabissmoke profiling was conducted via gas chromatography–mass spectroscopy, with a mean con-centration of 1% Δ9‐tetrahydrocannabinol determined. The smoke aliquots were transferred tothe lung biosimulator and expansion—contraction cycles were then initiated to mimic tidalbreathing. Baseline data confirmed that Curosurf works effectively under physiologically relevantconditions. Exposure to cannabis smoke from 2 independent batches reduced the Langmuir max-imum surface pressure values by approximately 20% and increased the compressibility term;interbatch variation was detected. Cannabis smoke impaired the ability of Curosurf to lowerthe surface tension term. This was ascribed to the penetration of the planar, hydrophobic druginto the two‐dimensional film, and destructive interaction with polar functionalities. The neteffect would be increased work of breathing for the individual.

Deviation in pulmonary surfactant structure–function activity can impair airway patency and lead to respiratory disorders. This novel study aims to evaluate the influence cigarette/e-cigarette vapour has on model surfactant films located within a simulated pulmonary environment using a lung biosimulator. Chromatographic analysis confirmed that nicotine levels were consistent with the sampling regimen employed. On exposure to smoke vapour, Langmuir isotherms exhibited condensed character and a significant reduction in maximum surface pressure was noted in all cases. Langmuir isocycles, reflective of the human breathing cycle, demonstrated condensed character on smoke vapour delivery. A reduction in the maximum surface pressure was clear only in the case of cigarette vapour application. The components of cigarette vapour can cause oxidative damage to pulmonary surfactant and impair recycling. Neutral nicotine molecules can weaken the structure of the monolayer and cause destabilisation. A protective effect was evident in the case of repeated surfactant compression – relaxation cycles (i.e. the ability to reduce the surface tension term was impaired less), demonstrating a likely innate biological defensive mechanism of the lung. E-cigarette vapour appeared to have a reduced impact on surfactant performance, which may hold value in harm reduction over the longer term

Partial specific volume is an important molecular parameter in the measurement of molecular masses by analytical ultracentrifugation and X-ray diffraction studies. Humic substances (aquatic fulvic and humic acids and peat humic acid) were isolated from a natural source (Whitray Fell, UK). The partial specific volumes ( ) have been studied by two independent methods, an analytical ultracentrifugation technique based on simultaneous sedimentation equilibrium measurements in water and deuterium oxide and by high precision digital densimetry. Measurements were made in a range of conditions from 0.01 M to 0.5 M salt concentration and in the humic substance concentration range 0.01 to 2 mg ml−1. Partial specific volumes in the range 0.43 to 0.63 cm3 g−1 were found depending on the samples and conditions. No evidence was found for a dependence of ( ) on humic concentration within the ranges studied. Both methods of measurements gave results in reasonable accord. The ultracentrifugation method was more precise for the aquatic fulvic acid than for the more polydisperse humic acids. For the fulvic sample the reproducibility of the ultracentrifugation method was ± 4.31%, comparable to the average reproducibility of the densimetry method which was ± 4.07% over a range of 12 different systems.

A human cranium was recovered from the River Witham, Lincoln, UK, at Stamp End Lock during a police operation in 2002. Although extensive trauma was noted, the skull was not of forensic interest since radiocarbon dating revealed that the individual had lived during the Roman occupation of Lincoln, almost 2,000 years ago. The skull had unusual black “metallic” staining on the occlusal surfaces of the teeth. As this kind of staining is relatively uncommon, it was investigated to determine the possible cause. An individual tooth was subjected to two elemental analyses: inductively coupled plasma-atomic emission spectroscopy (ICP-AES) and scanning electron microscopy-energy dispersive X-ray analysis (SEM-EDX). A small sample of modern teeth was also analysed for comparison to determine “normal” ranges of certain elements. Analysis of the ancient tooth shows very high levels of manganese (275 µg/g) and iron (1540 µg/g) compared to modern teeth values (1.90 µg/g Mn and 40.81 µg/g Fe). These results were consistent with the black staining arising from iron and manganese infiltrating bone and dental tissue from the depositional environment, and not a consequence of diet, pathological process or cultural practices.

Arson is a serious crime that affects society through cost, property damage, and loss of life. It is important that the methods and technologies applied by fire investigators in detection of evidence and subsequent analyses have a high degree of reliability, sensitivity, and be subject to rigorous quality control and assurance. There have been considerable advances in the field of arson investigation since the 1950s. Classification of ignitable liquids has been updated to include many new categories due to developments in the petroleum industry. Techniques such as steam or vacuum distillation and gas chromatography (GC) with flame ionization detection that may have been considered acceptable—even a benchmark—40 years ago, are nowadays generally disfavored, to the extent that their implementation may almost be considered as ignorance in the field. The advent of readily available mass spectrometric techniques has revolutionized the field of fire debris analysis, increasing the degree of sensitivity and discrimination possible considerably. Multi-dimensional GC—particularly GC × GC—while not yet widely applied, is rapidly gaining recognition as an important technique. This comprehensive review focuses on techniques and practices used in fire investigation, from scene investigation to analysis.