An investigation into the effect of surfactants on iron oxide powder suspension formulations for fingermark development

Iron oxide powder suspension (FePS) is a fingermark development technique that can be used on adhesive and non-porous surfaces, the efficacy of which is known to be influenced by the surfactant used in the formulation. Despite previous work optimising surfactants for use in FePS, there is limited understanding of the interactions between surfactants, powders and fingermark residue which aid the successful development of fingermarks. To better understand the effect of surfactant on development quality produced by FePS, this research assessed a wide range of surfactants of different ionic natures and evaluated their ability to develop fingermarks based on the quality of ridge detail, contrast and background development produced. It was found that surfactants play a critical role in the selective deposition of powder on fingermark residue, as formulations made with only water (no surfactant) produced heavy background deposition. The efficacy of each surfactant depended on the quality parameter considered, and the addition of some surfactants hindered fingermark development. Effective surfactants such as T20, KP and TX100 prevented background development and produced well contrasted developed marks. Poor contrast was produced by LN, SP80/T80 and T80 due to indiscriminate powder deposition either across the entire sample or preventing any powder to deposit on the surface, demonstrating the role surfactants play in allowing powder deposition in this technique. The effectiveness of a surfactant in PS was not directly dependent on its ionic nature, and most surfactants were more effective when diluted from stock concentrations. This research has provided a robust base for future work improving fundamental understanding of FePS, which will greatly aid the efficacy of future optimisation efforts.

A snapshot of injecting drug consumption from the analysis of used syringes within the Medically Supervised Injecting Centre in Sydney, Australia

INTRODUCTION

The administration of illicit drugs by injection is associated with considerable harm, including an increased risk of overdose. The chemical analysis of used syringes can enhance knowledge on injecting drug consumption beyond traditional data sources (self-report surveys). This additional information may be useful during significant global events like the COVID-19 pandemic. This study aimed to examine a snapshot of the drugs injected at the Medically Supervised Injecting Centre (MSIC) in Sydney, Australia, in 2019-2020.

METHODS

Used syringes were collected from MSIC across three periods throughout 2019 and 2020 (February 2019, March-April 2020 and June-September 2020). Drug residues were extracted from used syringes using methanol before detection by gas chromatography-mass spectrometry and ultra-performance liquid chromatography-tandem mass spectrometry. The chemical analysis results were compared to self-report data obtained from MSIC clients.

RESULTS

Heroin (46-53%), methamphetamine (24-34%) and pharmaceutical opioids (15-27%) were the most common drug residues detected. The chemically detected drugs had declining coherence with the drugs self-reported by MSIC clients across the time periods examined.

DISCUSSION AND CONCLUSIONS

There was no significant change in the drugs injected (heroin, methamphetamine and pharmaceutical opioids) across the three periods collected throughout varying COVID-19 lockdown restrictions. Changes in the frequency of other drugs injected and discrepancies between chemical analysis and self-report were potentially related to regulatory changes, degradation or misinformed sales. Routine chemical analysis of used syringes has provided an alternative information source to promote awareness of current drug trends and aid harm reduction.

Organic impurity profiling of 3,4-methylenedioxyamphetamine (MDA) synthesised from helional

The organic impurity profile of 3,4-methylenedioxyamphetamine (MDA) synthesised from helional via the "twodogs" method was examined to identify route-specific and condition-specific impurities. The synthesis used a condensation reaction, followed by a Beckmann rearrangement, then Hofmann rearrangement, and then conversion to a hydrochloride salt. Two chlorinating agents were investigated for the Hofmann rearrangement reaction, trichloroisocyanuric acid (TCCA) and sodium hypochlorite. Three route-specific impurities were identified in MDA using TCCA, and two of these impurities were condition-specific such that the impurities that formed were dependent on the alcohol used as solvent. Three additional impurities were identified as non-route-specific as they have previously been identified in MDA synthesised from 3,4-methylenedioxycinnamic acid or piperonal. These non-route-specific impurities were also identified in MDA synthesised using sodium hypochlorite. No impurities were detected in MDA hydrochloride. This study identified route- and condition-specific organic impurities in MDA synthesised via the "twodogs" synthetic route using helional as starting material. The results in this study provide further understanding into the illicit synthesis of MDA and highlight the expanding nature of precursors used for illicit drug manufacture. It provides valuable information to decision makers to enact legislative measures and restrict precursors of concern.

Fingermark quality assessment, a transversal study of subjective quality scales

Fingermark detection research aims to improve the quantity and quality of fingermarks detected through the development of novel techniques. Subsequently, there is a need to evaluate these methods to determine the quality of the developed mark. Since the 1980's there has been a significant number of publications, which utilise a variety of different quality assessment methods. The introduction of common practice methods from the International Fingerprint Research Group (IFRG) aimed to implement a more standardised approach. Although these schemes are recommended as common practice, they are only guidelines. Consequentially, there is currently no universally accepted method to evaluate the enhancement techniques implemented in research. Therefore, this study aimed to collate and analyse the published protocols being used within fingermark detection research in order to better understand their application and how research is currently analysing and interpreting fingermark quality. This study comprised of manual and automatic searches of over 2000 published papers within the fingermark detection area. After thorough analysis of the articles, 396 published papers were found to have used a scale within the years spanning 1998-2022. The number of publications that report the use of a scale to assess quality for fingermark detection research has considerably increased over the last decade. However, whilst the number of publications utilising scales has increased, it is not proportional to the number of papers using the IFRG scales. The choice of scale is often institution specific and even more specific to their location. There are also numerous different adaptations of the IFRG recommended scales, as well as novel scales, which do not associate with the IFRG recommended versions being introduced the more research continues to grow. One such reason for this is investigated here, as different quality parameters are utilised within each individual scale. There is underrepresentation of these quality parameters within some of the IFRG scales, in particular the Centre for Applied Science and Technology (CAST) scale. This correlates to the considerable number of tailored approaches as authors are forced to add these parameters within the descriptions. Until there is an introduction of clear guidelines surrounding all areas of fingermark quality, from definition to parameters chosen within phases, the research area will continue to face such issues. This article recommends areas of potential study, whilst also recommending procedures that may be employed to alleviate some of the issues seen with fingermark quality evaluation.

Comparison of carbon and iron oxide based powder suspension formulations

Powder suspensions (PS) are a fingermark development technique made up of a mixture of an insoluble powder and surfactant solution. In the UK, carbon-based PS is used operationally on adhesive surfaces while iron oxide-based PS is used on flexible plastics. In NSW, Australia, only carbon-based suspensions are used due to a lack of research using iron oxide PS in an Australian context. In this research, a range of iron oxide powders and surfactant types were tested to optimise two iron oxide formulations. General observations found that thinner suspensions improved the ease of use in this technique while slightly improving the quality of developed fingermarks. The first optimised formulation involved a magnetic iron-oxide from Fisher Scientific mixed with a dilute Triton X-100 surfactant, and the other an iron-oxide nanopowder from Sigma Aldrich mixed with a 4% Tween 20 solution. The two formulations were then compared with a pre-mixed carbon-based PS, Wet Powder. This comparison showed that the effectiveness of each formulation is heavily dependent on substrate type. Both formulations had issues with heavy background staining on different kinds of surfaces. However, Wet Powder was shown to be the most consistently effective fingermark detection technique overall, especially on adhesive tapes. Despite this, iron-oxide PS were still a highly effective fingermark development technique, notably on plastic surfaces.

Comparison of NIR powders to conventional fingerprint powders

Fingerprint powders remain one of the most common detection techniques used at the crime scene. However, powder efficiency and contrast can be hindered when applied to highly patterned backgrounds. This problem can be overcome using powders that are luminescent in the near-infrared (NIR) region of the electromagnetic spectrum. Despite being commercially available, those powders have been the focus of only a small number of studies, limited to a few substrates or donors. Their performance and advantages over common techniques are still to be thoroughly investigated. This study aims at assessing the performances of two NIR powder (fpNATURAL 1® and Universal Powder an in-house developed powder) against two conventional powders, a black and a luminescent powder (Sirchie Black, GREENcharge™) under various optical conditions (white light, visible luminescence and NIR luminescence). The powders were compared on four substrates using fingermarks of four different ages from five donors. A total 900 fingermarks were collected for each pairwise comparison. NIR imaging provided good background suppression and a high contrast, however it was shown that conventional powders remained the most effective powdering methods on the substrates tested as sufficient contrast could be achieved under white light or in luminescent mode in the visible region. The results showed that Universal Powder performed similarly to conventional powders, but poor performances were obtained on most substrates with fpNATURAL 1®. Based on the results obtained, it is recommended to use NIR powders only on substrates or conditions where traditional powders are known to perform poorly.

Evaluating the effect of barrel length on pellet distribution patterns of sawn-off shotguns

In recent years, sawn-off shotguns have been regularly encountered in firearm-related incidents. Shotgun represents a community threat due to their ability to be shortened in order to improve their concealability. In practice, forensic scientists and investigators may be asked to determine if a shotgun used in a particular event might have been shortened based on the pellet distribution. To investigate the effect of altering the barrel length on pellet distribution, five 12-gauge shotguns were progressively shortened. Each shotgun was assessed at six barrel lengths and a single discharge of No. 4 shot shotshell ammunition was fired at a fixed fabric target. The shotguns were positioned at six different distances from target and experiments conducted in triplicate. The fabric targets containing pellet pattern underwent data analysis to calculate the pellet distribution area. At short distances from target (≤ 1.0 m), the pellet penetration was observed as a single entry point as the pellets did not have a sufficient flight time to spread from each other. For distances of 2.5 m, 5 m and 10 m, pellet penetration patterns were observed and a quantitative analysis was performed on the samples containing pellet distribution patterns. At each of these distances, it was detected that there was a noticeable increase in pellet distribution area between the unaltered shotgun and altered barrel lengths for all shotguns. The distance from the target as well as the presence of a choke in the shotgun's barrel was found to have a greater impact on the pellet distribution than the barrel length.

Impact of one-step luminescent cyanoacrylate treatment on subsequent DNA analysis

Fingermarks can be exploited for both their ridge detail and touch DNA. One-step luminescent cyanoacrylate (CA) fuming techniques used for fingermark enhancement, such as PolyCyano UV (Foster+Freeman Ltd) and Lumicyano™ (Crime Science Technology), claim to be compatible with DNA analysis as they reduce the need for post-staining to increase contrast of the developed fingermark. The aim of this study was to determine the impact that these one-step luminescent cyanoacrylates have on DNA analysis and how they compare to conventional CA techniques. Four donors each deposited five sets of natural fingermarks, to which a known amount of washed saliva cells was dispensed onto half of each set of fingermarks. Each set was treated with either a conventional CA technique or a one-step luminescent CA technique prior to collection and processing of DNA, with one set left as a non-fumed control. It was found that DNA was still recoverable and detectable following each of the treatments. Lumicyano™ had a similar impact on DNA profiles as conventional CA fuming and with post-stain, however, the degradation effect of PolyCyano UV on DNA was greater than the conventional treatments. For quantities of DNA such as that from touch DNA, the use of PolyCyano UV to enhance fingermarks may impact subsequent DNA analysis by causing allele drop out at larger fragment sizes.

Dataset of coded handwriting features for use in statistical modelling

The data presented here is related to the article titled, “Using handwriting to infer a writer's country of origin for forensic intelligence purposes” (Agius et al., 2017) [1]. This article reports original writer, spatial and construction characteristic data for thirty-seven English Australian1 writers and thirty-seven Vietnamese writers. All of these characteristics were coded and recorded in Microsoft Excel 2013 (version 15.31). The construction characteristics coded were only extracted from seven characters, which were: ‘g’, ‘h’, ‘th’, ‘M’, ‘0’, ‘7’ and ‘9’. The coded format of the writer, spatial and construction characteristics is made available in this Data in Brief in order to allow others to perform statistical analyses and modelling to investigate whether there is a relationship between the handwriting features and the nationality of the writer, and whether the two nationalities can be differentiated. Furthermore, to employ mathematical techniques that are capable of characterising the extracted features from each participant.

Using handwriting to infer a writer's country of origin for forensic intelligence purposes

Forensic science has traditionally focused the majority of its resources and objectives towards addressing Court-related questions. However, this view restricts the contribution of forensic science to one process and results in a loss of information as the investigative and intelligence roles are largely neglected. A forensic science discipline suffering from this imbalance is handwriting examination, which may be characterised as a time consuming and subjective process that is mostly carried out towards the end of the investigation for the purpose of judicial proceedings. Individual and habitual characteristics are the major handwriting features exploited, however alternate information concerning the author's native language could potentially be used as a key element in an intelligence framework. This research focussed on the detection of characteristics that differentiate Vietnamese and English Australian writers based on their English handwriting. The study began with the extraction of handwriting characteristics from the writing of people from the two populations. The data was analysed using a logistic regression model and a classification and regression tree (CRT). Each recognised four class characteristics that were capable of distinguishing between the two nationalities. The logistic regression and CRT models were both capable of correctly predicting 93% of cases. Their predictive capabilities were then tested and supported using blind exemplars in order to mirror casework settings. It appeared that when using their respective class characteristics, the two models were capable of differentiating English Australians from Vietnamese in the data set. This proof of concept research demonstrated the plausibility of exploiting this additional information from a handwriting trace and taking advantage of it in an intelligence-led framework.

The use of handwriting examinations beyond the traditional court purpose

Traditionally, forensic science has predominantly focused its resources and objectives on addressing court related questions. However, this view restricts the contribution of forensic science to one function and results in lost opportunities as investigative and intelligence roles are often overlooked. A change of perspective and expansion of the contributions of forensic science is required to take advantage of the benefits of abductive and inductive thought processes throughout the investigative and intelligence functions. One forensic discipline that has the potential to broaden its traditional focus is handwriting examination. Typically used in investigations that are focused on both criminal and civil cases, the examination procedure and outcome are time consuming and subjective, requiring a detailed study of the features of the handwriting in question. Traditionally, the major handwriting features exploited are characteristics that are often considered individual (or at least highly polymorphic) and habitual. However, handwriting can be considered as an information vector in an intelligence framework. One such example is the recognition of key elements related to the author's native language. This paper discusses the traditional method generally used around the world and proposes a theoretical approach to expand the application of handwriting examination towards gaining additional information for intelligence purposes. This concept will be designed and tested in a future research project.

Dispersion of positron emitting radioactive gases in a complex urban building array: a comparison of dose modelling approaches

A radiological assessment was carried out on the release of positron-emitting radioactive gases from a roof-level stack at a central London site. Different modelling approaches were performed to investigate the range of radiation doses to representative persons. Contributions from plume inhalation, gamma shine and immersion to effective dose were taken into account. Dry and wet surface deposition on the roof, and exposure from contamination on the skin of roof-workers, added only a mean 4.7% to effective dose and were neglected. A 1:200 scale model, consisting of the stack and surrounding buildings, was tested in a wind tunnel to simulate pollutant dispersion in the near-field region i.e. rooftop. Concentration field measurements in the wind tunnel were converted into effective dose, including for roof-workers installing glass cladding to the stack building. Changes in the building shape, from addition of the cladding layer, were investigated in terms of the near-field flow pattern and significant differences found between the two cases. Pollutant concentrations were also modelled using Air Dispersion Modelling System (ADMS) and the results used to calculate the effective dose using the same meteorological data set and source release terms. Sector averaged wind tunnel dose estimates were greater than the ADMS figure by approximately a factor of two to three. Different stack release heights were investigated in the wind tunnel and ADMS simulations in order to determine the best height for the replacement flue stack for the building. Other techniques were investigated: building wake models, modified Gaussian plume methods and uniform dilution into a hemispherical volume to show the wide variation in predicted dose possible with different approaches. Large differences found between simpler analytic approaches indicated that more robust radiological assessments, based on more complex modelling approaches, were required to achieve satisfactory estimates of radiation dose to representative groups in adjacent buildings and on the building rooftop.

The use of a failed flap as a biological dressing

A patient with a narrowly excised squamous cell carcinoma on the scalp underwent a wider excision that involved burring of the underlying calvarium. The defect was reconstructed with a superficial temporal artery pedicled flap, which unfortunately failed. The patient had multiple co-morbidities, limiting reconstructive options. The failed flap was therefore maintained as a 'biological dressing' for several weeks. During this time, the patient was reviewed regularly in the dressing clinic and did not develop a wound infection. Six weeks later, he was taken back to theatre and the flap was debrided under local anaesthesia. Beneath the flap, there was sufficient healthy granulation tissue over the site of previous bony debridement to permit split skin grafting. We advocate this technique as a useful method for managing difficult wounds in complex patients with multiple co-morbidities where other reconstructive techniques are limited.

Thirteen Patients with MAT1A Mutations Detected Through Newborn Screening: 13 Years' Experience

BACKGROUND

Methionine adenosyltransferase I/III (MATI/III) deficiency is the most common genetic cause of persistent isolated hypermethioninemia. Patients and Methods : This is a retrospective data analysis of 62 newborns with elevated methionine detected by newborn screening between January 2000 and June 2013. The clinical, biochemical, and molecular findings of a subset of these children with MAT1A mutations associated with MATI/III deficiency are presented.

RESULTS

Of the 62 newborns with elevated methionine, 12 were identified as having classical homocystinuria; 37 were false-positives; and 13 were found to have isolated persistent hypermethioninemia in the absence of biochemical markers of homocystinuria, abnormal liver function studies, or other causes of elevated methionine. These 13 individuals underwent genetic testing for changes in the MAT1A gene, associated with MATI/III deficiency. Three of 13 were found to have the common autosomal dominant R264H mutation, one was found to be a compound heterozygote for two novel pathogenic mutations, and three were found to be heterozygotes for previously reported mutations shown to cause autosomal recessive MATI/III deficiency when present in homozygous or a compound heterozygous configuration. The remaining six patients had variants of unknown clinical significance or novel mutations. For the majority of individuals, methionine persisted above the normal range but trended downward over time. None of these 13 individuals was started on a low-methionine diet, and all have age-appropriate growth and development.

CONCLUSION

These cases show that individuals with even single changes in the MAT1A gene may have elevations in methionine identified by newborn screening, which may persist for months after birth without any clinical consequences.

Styryl dye coated metal oxide powders for the detection of latent fingermarks on non-porous surfaces

Conventional fingermark powders rely on contrast induced by absorption/reflection (e.g. black powder) or luminescence in the visible region (e.g. Blitz Green(®)). In most cases, these powders provide sufficient contrast; however, in some circumstances surface characteristics can interfere with the visualisation of powdered fingermarks. Visualisation in the near infra-red (NIR) region, however, has been shown to eliminate interferences commonly encountered in the visible region. In this study, a mixture of rhodamine 6G and the NIR laser dye styryl 11 (STaR 11) was coated onto an aluminium oxide nanopowder and then mixed with silver magnetic powder to develop and visualise fingermarks in the NIR. When compared to Blitz Green(®), it was determined that the STaR 11 magnetic powder was better suited for marks deposited on textured surfaces and for older marks, whereas Blitz Green(®) performed better on smooth glossy surfaces. The ability of the STaR 11 mixed dye formulation to be visualised in both the visible and NIR regions also provides a significant advantage over conventional luminescent fingermark powders.

Formation of Separated versus Contact Ion Triplets in Magnesium Thiolates. Synthesis and Characterization of [Mg(15-crown-5)(SCPh(3))(2)] and [Mg(15-crown-5)(THF)(2)][S-2,4,6-tBu(3)C(6)H(2))](2)

The synthesis and structural characterization of two magnesium thiolate complexes are described. Both compounds were prepared by analogous reactions routes, namely, alkane elimination and transamination, but using differently sized ligands. Utilization of the smaller HSCPh(3), resulted in the formation of [Mg(15-crown-5)(SCPh(3))(2)], 1, displaying a seven-coordinate magnesium center with two magnesium-sulfur bonds. Employment of the sterically more encumbered HS-2,4,6-tBu(3)C(6)H(2) yielded a separated cation and anions as displayed in [Mg(15-crown-5)(THF)(2)][S-2,4,6-tBu(3)C(6)H(2)](2), 2. Compound 2 exhibits a seven-coordinate cation, completing its coordination environment with five metal-crown-ether interactions in addition to two tetrahydrofuran (THF) contacts. The compounds were characterized by IR and NMR spectroscopy in addition to X-ray crystallography. Crystal data with Mo Kalpha (lambda = 0.710 73 Å) are as follows: 1, C(48)H(50)MgO(5)S(2), a = 8.4785(4) Å, b = 9.3595(5) Å, c = 13.8306(6) Å, alpha = 87.332(1) degrees, beta = 85.929(1) degrees, gamma = 68.733(1) degrees, Z = 1, triclinic; 2, C(54)H(94)MgO(7)S(2), a = 13.6755(2) Å, b = 12.8045(6) Å, c = 32.7127(12) Å, beta = 97.87(1) degrees, Z = 4, monoclinic.

The in vivo effects of milrinone on the airways of cystic fibrosis mice and human subjects

Previous studies have indicated that milrinone, a specific type III phosphodiesterase inhibitor, may be able to induce chloride secretion in cystic fibrosis (CF) tissues. We have now assessed the effect of this agent in vivo on the nasal epithelium of CF mutant mice and also in the nose and lungs of human subjects with CF. Wild-type mice showed a small hyperpolarization of the nasal potential difference (PD) in response to milrinone (100 microM, 1.6 +/- 0.6 mV, n = 8, P < 0.05). In contrast, CF mice carrying either the most common human mutation of the gene for the CF transmembrane regulator (CFTR), DeltaF508 (protein mislocalized), or the G551D mutation (protein normally localized) failed to demonstrate this response. Milrinone perfused alone had no significant effect on the baseline nasal PD of human subjects without CF (14.7 +/- 4.0 mV preperfusion; 15.3 +/- 4.6 mV postperfusion), but significantly (P < 0.05) augmented the hyperpolarization induced by a subsequently perfused low-chloride solution (with milrinone, 36.8 +/- 3.0 mV, n = 6; without milrinone, 18.1 +/- 2.2 mV, n = 19). In contrast, in human subjects with CF (n = 6), milrinone alone significantly (P < 0. 05) altered the nasal baseline PD (52.2 +/- 3.3 mV preperfusion; 57. 4 +/- 4.2 mV, postperfusion) but not the subsequent responses to the low-chloride solution (with milrinone, 1.1 +/- 2.2 mV, n = 4; without milrinone, 0.6 +/- 0.5 mV, n = 28) or to isoproterenol (100 microM). In a separate study in subjects (n = 6) with the DeltaF508 mutation, nasal coadministration of milrinone with isoproterenol produced no effect in the presence of amiloride and a low-chloride solution (-0.8 +/- 0.5 mV). This was also the case in the nasal epithelium of CF subjects (n = 4) carrying at least one G551D allele (-0.3 +/- 0.8 mV). Similarly, milrinone did not hyperpolarize the PD of either the tracheal (n = 6) or segmental (n = 6) airways of CF subjects (DeltaF508) when applied topically in vivo in the presence of amiloride, isoproterenol, or adenosine triphosphate (all 100 microM) in a low-chloride solution. These data do not support the use of milrinone to induce chloride secretion in CF airways in vivo.

Syntheses and Structure Determinations of Calcium Thiolates

The exploration of synthetic methodologies toward heavy alkaline-earth chalcogenolates resulted in the preparation and structural characterization of a family of calcium thiolates, including [Ca(SC(6)F(5))(2)(py)(4)], 1 (py = pyridine), the separated ion-triple [Ca(18-crown-6)(NH(3))(3))][SMes](2).2THF, 2 (Mes = 2,4,6-tBu(3)C(6)H(2)), and the contact triple [Ca(18-crown-6)(SMes)(2)].THF, 3. Compound 1 was prepared by treating [Ca(N(SiMe(3))(2))(2)](2) with 4 equiv of HSC(6)F(5) under addition of pyridine. The thiolates 2 and 3 were synthesized by treatment of calcium metal dissolved in dry, liquid NH(3) under addition of 2 equiv of HSMes and crown ether or, alternatively, by the reduction of MesSSMes with calcium metal in dry, liquid ammonia. We also report two reaction products isolated during attempted calcium thiolate syntheses: [CaBr(4)(THF)(2)(&mgr;(2)-Li)(2)(THF)(4)], 4, isolated as the product of a salt elimination reaction between CaBr(2) and 2 equiv of [Li(THF)(n)()S-2,4,6-(i)()Pr(3)C(6)H(2)](m)(). [(NH(4))(py)(SC(6)F(5))], 5, was obtained as the sole product in the reaction of metallic calcium with HSC(6)F(5) in liquid ammonia under addition of pyridine. All compounds were characterized by single-crystal X-ray crystallography in addition to IR and NMR spectroscopy.