Energy Resolved Mass Spectrometry for Interoperable Non-resonant Collisional Spectra in Metabolomics

In untargeted metabolomics, the unambiguous identification of metabolites remains a major challenge. This requires high-quality spectral libraries for reliable metabolite identification, which is essential for translating metabolomics data into meaningful biological information. Several attempts have been made to generate reproducible product ion spectra (PIS) under a low collision energy (ELab) regime and nonresonant collisional conditions but have not fully succeeded. We examined the ERMS (energy-resolved mass spectrometry) breakdown curves of two lipo-amino acids and showed the possibility to highlight "singular points", called descriptors hereafter (linked to respective ELab depending on the instrument), for each of the monomodal product ion profiles. Using several instruments based on different technologies, the PIS recorded at these specific ELab sites shows remarkable similarities. The descriptors appeared as being independent of the fragmentation mechanisms and can be used to overcome the main instrumental effects that limit the interoperability of spectral libraries. This proof-of-concept study, performed on two particular lipo-amino acids, demonstrates the high potential of ERMS-derived information to determine the instrument-specific ELab at which PIS recorded in nonresonant conditions become highly similar and instrument-independent, thus comparable across platforms. This innovative but straightforward approach could help remove some of the obstacles to metabolite identification in nontargeted metabolomics, putting an end to a challenging chimera.

Spatialized Metabolomic Annotation Combining MALDI Imaging and Molecular Networks

MALDI mass spectrometry imaging has gained major interest in the field of chemical imaging. This technique makes it possible to locate tens to hundreds of ionic signals on the sample surface without any a priori. One of the current challenges is still the limited ability to annotate signals in order to convert m/z values into probable chemical structures. At the same time, data obtained by LC-MS/MS have benefited from the development of numerous chemoinformatics tools, in particular molecular networks, for their efficient annotation. For the first time, we present here the combination of MALDI-FT-ICR imaging with molecular networks from MALDI-MS/MS data directly acquired on plant tissue sections. Annotation improvements are demonstrated, paving the way for new annotation pipelines for MALDI imaging.

Development, design and experience of the UK Military's return to diving pathway following SARS-CoV-2 infection

After the emergence of the SARS-CoV-2 virus in early 2020, it quickly became clear that symptomatic or asymptomatic infection had the potential to negatively impact on an individual's fitness to dive through effects on the respiratory, cardiovascular or neurological systems. The significance of these effects in the military diving environment was initially unclear due to an absence of data concerning incidence, chronology or severity. In order to safely return divers to the water and maintain operational capability, the UK Military developed a pathway for SARS-CoV-2 positive divers that stratified risk of sequelae and extent of required clinical investigation, while minimising reliance on viral testing and hospital-based investigations. We present this process, provide rationale and support for its design and detail the number of SARS-CoV-2 positive divers who have been returned to full diving fitness following infection of varying degrees of severity.

Large-Scale Interlaboratory DI-FT-ICR MS Comparability Study Employing Various Systems

Ultrahigh resolution mass spectrometry (UHR-MS) coupled with direct infusion (DI) electrospray ionization offers a fast solution for accurate untargeted profiling. Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometers have been shown to produce a wealth of insights into complex chemical systems because they enable unambiguous molecular formula assignment even if the vast majority of signals is of unknown identity. Interlaboratory comparisons are required to apply this type of instrumentation in quality control (for food industry or pharmaceuticals), large-scale environmental studies, or clinical diagnostics. Extended comparisons employing different FT-ICR MS instruments with qualitative direct infusion analysis are scarce since the majority of detected compounds cannot be quantified. The extent to which observations can be reproduced by different laboratories remains unknown. We set up a preliminary study which encompassed a set of 17 laboratories around the globe, diverse in instrumental characteristics and applications, to analyze the same sets of extracts from commercially available standard human blood plasma and Standard Reference Material (SRM) for blood plasma (SRM1950), which were delivered at different dilutions or spiked with different concentrations of pesticides. The aim of this study was to assess the extent to which the outputs of differently tuned FT-ICR mass spectrometers, with different technical specifications, are comparable for setting the frames of a future DI-FT-ICR MS ring trial. We concluded that a cluster of five laboratories, with diverse instrumental characteristics, showed comparable and representative performance across all experiments, setting a reference to be used in a future ring trial on blood plasma.

Return to flying duties of German military pilots after recovery from COVID-19

BACKGROUND

Pilots are working in a unique and exacting environment with hypobaric hypoxia and acceleration forces. In military flying, missions are often challenging with possible combat scenarios and in remote areas with impaired infrastructure.

METHODS

We analysed all German military pilots and pilot candidates with confirmed SARS-CoV-2 infection, who have all been evaluated prior to their return to flying duties between April 2020 and January 2022 by the German Air Force Centre of Aerospace Medicine. Symptoms, comorbidities, scope of investigations, examination results, vaccination status and aeromedical disposition are described.

RESULTS

90 pilots (82 active pilots and 8 pilot candidates) with a median age of 35 years (IQR 15 years) were included. 78 pilots (87%) reported symptoms, with median duration of 6 days. Symptoms included influenza-like symptoms (70.0%), headache (45.6%), impaired physical fitness (37.8%), anosmia/ageusia (36.7%), fever (27.8%), exertional dyspnoea (8.9%), memory and concentration disorders (4.4%), diarrhoea (3.3%) and dyspnoea at rest (2.2%). Only one pilot (1.1%) was hospitalised, two (2.2%) required outpatient treatment. All pilots were allowed to return to unrestricted flying duties after the assessment, with eight (8.9%) reporting ongoing mild symptoms.

CONCLUSION

Due to their demanding working environment, pilots, and other high-hazard employees, should undergo medical evaluation prior to return to their duties to exclude ongoing symptoms and the development of post-acute COVID-19 or post-COVID-19 syndrome. The scope of examinations may depend on the severity of the disease, comorbidities, the vaccination status, the predominant SARS-CoV-2 variant and the type of aircraft flown.

Fourier transform ion cyclotron resonance mass spectrometry at the true cyclotron frequency

Ion cyclotron resonance (ICR) cells provide stability and coherence of ion oscillations in crossed electric and magnetic fields over extended periods of time. Using the Fourier transform enables precise measurements of ion oscillation frequencies. These precisely measured frequencies are converted into highly accurate mass-to-charge ratios of the analyte ions by calibration procedures. In terms of resolution and mass accuracy, Fourier transform ICR mass spectrometry (FT-ICR MS) offers the highest performance of any MS technology. This is reflected in its wide range of applications. However, in the most challenging MS application, for example, imaging, enhancements in the mass accuracy of fluctuating ion fluxes are required to continue advancing the field. One approach is to shift the ion signal power into the peak corresponding to the true cyclotron frequency instead of the reduced cyclotron frequency peak. The benefits of measuring the true cyclotron frequency include increased tolerance to electric fields within the ICR cell, which enhances frequency measurement precision. As a result, many attempts to implement this mode of FT-ICR MS operation have occurred. Examples of true cyclotron frequency measurements include detection of magnetron inter-harmonics of the reduced cyclotron frequency (i.e., the sidebands), trapping field-free (i.e., screened) ICR cells, and hyperbolic ICR cells with quadrupolar ion detection. More recently, ICR cells with spatially distributed ion clouds have demonstrated attractive performance characteristics for true cyclotron frequency ion detection. Here, we review the corresponding developments in FT-ICR MS over the past 40 years.

Sclareol and linalyl acetate are produced by glandular trichomes through the MEP pathway

Sclareol, an antifungal specialized metabolite produced by clary sage, Salvia sclarea, is the starting plant natural molecule used for the hemisynthesis of the perfume ingredient ambroxide. Sclareol is mainly produced in clary sage flower calyces; however, the cellular localization of the sclareol biosynthesis remains unknown. To elucidate the site of sclareol biosynthesis, we analyzed its spatial distribution in the clary sage calyx epidermis using laser desorption/ionization mass spectrometry imaging (LDI-FTICR-MSI) and investigated the expression profile of sclareol biosynthesis genes in isolated glandular trichomes (GTs). We showed that sclareol specifically accumulates in GTs' gland cells in which sclareol biosynthesis genes are strongly expressed. We next isolated a glabrous beardless mutant and demonstrate that more than 90% of the sclareol is produced by the large capitate GTs. Feeding experiments, using 1-¹³C-glucose, and specific enzyme inhibitors further revealed that the methylerythritol-phosphate (MEP) biosynthetic pathway is the main source of isopentenyl diphosphate (IPP) precursor used for the biosynthesis of sclareol. Our findings demonstrate that sclareol is an MEP-derived diterpene produced by large capitate GTs in clary sage emphasing the role of GTs as biofactories dedicated to the production of specialized metabolites.

The temporal analysis of elite breaststroke swimming during competition

Breaststroke is the only competitive stroke characterised by propulsive discontinuity. It is consequently paramount that swimmers optimally coordinate limb movements in order to maintain the highest average velocity possible. The present study aimed to investigate the temporal patterns of elite breaststroke swimmers. 50 m long-course competition footage of (1) 20 male 100 m races, (2) 24 female 100 m races, (3) 15 male 200 m races, and (4) 27 female 200 m races from 2018 to 2020 were digitised and analysed. Six points within each stroke cycle were identified and used to calculate 15 temporal parameters. Analyses revealed multiple temporal pattern differences between groups based on sex and race distance. It is recommended that coaches individualise swimmers' breaststroke temporal patterns based on individual needs, strengths, and morphological characteristics.

Chemical Processes Involving 18-Crown-6-Ether in Activated Noncovalent Complexes with Protonated Peptides

These last decades, it has been widely assumed that 18-crown-6-ether (CE) plays a spectator role during the chemical processes occurring in isolated host-guest complexes between peptides or proteins and CE after activation in mass spectrometers. Our present experimental and theoretical results challenge this hypothesis by showing that CE can abstract a proton or a protonated molecule from protonated peptides after activation by collisions in argon or electron capture/transfer. Furthermore, thanks to comparison between experimental and calculated values of collision cross-sections, we demonstrate that CE can change binding site after electron transfer. We also propose detailed mechanisms for these processes.

Does industry funding differ between men and women in electrophysiology and devices research?

Funding Acknowledgements

Type of funding sources: None.

Background

A significant gender bias has been identified in cardiology. Industry funding may be important developing electrophysiology (EP) and devices research. Such funding leads to potential conflicts of interest (COI) which must be disclosed on research presentations. There is limited evidence whether the gender bias in cardiology extends to industry funding of research.

Purpose

To assess whether COI disclosures in EP and devices presentations at the ESC Annual Congress differ between men and women.

Methods

Recorded presentations from the Arrhythmia & Devices section of ESC Annual Congresses 2016-2020 were assessed. Presentations were excluded if the original presentation contained no slides, it was a panel discussion, it was a non-scientific presentation, or part of the presentation was missing. Presentations with multiple speakers were also excluded. Chi-squared and Mann-Whitney U tests were used to assess differences between groups for dichotomous and continuous data respectively.

Results

Of 1,153 presentations assessed, 999 were suitable for inclusion. Women made up 22% (n = 221) of presenters. There was no difference in whether COI declaration slides were missing between women (5.9%, n = 13) and men (7.6%, n = 56), p = 0.38. In those with COI disclosure slides (n = 927), women declared significantly lower median number of COIs (0, IQR 0-3) compared with men (2, IQR 0-8), p < 0.0001. In contrast, women spent a greater time-per-word on their COI disclosure slides (250ms, IQR 125-375ms) compared with men (200ms, IQR 118-333ms), p < 0.0001.

Conclusions

Women made up a minority of presenters in EP/devices talks at the ESC annual congress. Women were less likely to have COIs which may suggest that they are less likely to receive industry funding. Despite this, women spent a greater amount of time-per-word on their COI slides. The lower number of declared COIs in women highlights another potential area of gender bias in cardiology that needs further investigation so that it can be addressed.

SPIX: A new software package to reveal chemical reactions at trace amounts in very complex mixtures from high‐resolution mass spectra dataset

Rationale

High‐resolution mass spectrometry based non‐targeted screening has a huge potential for applications in environmental sciences, engineering and regulation. However, it produces large datasets for which full appropriate processing is a real challenge; the development of processing software is the last building‐block to enable large‐scale use of this approach.

Methods

A new software application, SPIX, has been developed to extract relevant information from high‐resolution mass spectral datasets. Dealing with intrinsic sample variability and reducing operator subjectivity, it opens up opportunities and promising prospects in many areas of analytical chemistry. SPIX is freely available at: http://spix.webpopix.org.

Results

Two features of the software are presented in the field of environmental analysis. An example illustrates how SPIX reveals photodegradation reactions in wastewater by fitting kinetic models to significant changes in ion abundance over time. A second example shows the ability of SPIX to detect photoproducts at trace amounts in river water, through comparison of datasets from samples taken before and after irradiation.

Conclusions

SPIX has shown its ability to reveal relevant modifications between two series of large datasets, allowing, for instance, the study of the consequences of a given event on a complex substrate. Most of all – and it is to our knowledge the only software currently available allowing this – it can reveal and monitor any kind of reaction in all types of mixture.

Defence Medical Rehabilitation Centre (DMRC) COVID-19 Recovery Service

Coronavirus disease 2019 (COVID-19) causes significant mortality and morbidity, with an unknown impact in the medium to long term. Evidence from previous coronavirus epidemics indicates that there is likely to be a substantial burden of disease, potentially even in those with a mild acute illness. The clinical and occupational effects of COVID-19 are likely to impact on the operational effectiveness of the Armed Forces. Collaboration between Defence Primary Healthcare, Defence Secondary Healthcare, Defence Rehabilitation and Defence Occupational Medicine resulted in the Defence Medical Rehabilitation Centre COVID-19 Recovery Service (DCRS). This integrated clinical and occupational pathway uses cardiopulmonary assessment as a cornerstone to identify, diagnose and manage post-COVID-19 pathology.

UV-visible photodegradation of naproxen in water - Structural elucidation of photoproducts and potential toxicity

The UV-visible photodegradation of Naproxen (6-methoxy-α-methyl-2-naphthaleneacetic acid, CAS: 22204-53-1), one of the most used and detected non-steroidal anti-inflammatory drugs (NSAIDs) in the world, and its ecotoxicological consequences were investigated in an aqueous medium. The photo-transformation products were analyzed and the structures of photoproducts were elucidated using gas chromatography coupled with tandem mass spectrometry (GC-MS/MS) and high-performance liquid chromatography coupled with ultrahigh-resolution Fourier transform ion cyclotron resonance mass spectrometry (LC-FTICR-MS). Seven photoproducts were detected and characterized, photo-transformation mechanisms have been postulated to rationalize their formation under irradiation. In silico Q.S.A.R. (Quantitative Structure-Activity Relationship) toxicity predictions were performed with the Toxicity Estimation Software Tool (T.E.S.T.) and in vitro assays were carried out on Vibrio fischeri bacteria. Some of the obtained photoproducts exhibit higher potential toxicity than Naproxen itself but the whole toxicity of the irradiated solution is not of major concern.

Narrow Aperture Detection Electrodes ICR Cell with Quadrupolar Ion Detection for FT-ICR MS at the Cyclotron Frequency

Ion signal detection at the true (unperturbed) cyclotron frequency instead of the conventional reduced cyclotron frequency has remained a formidable challenge since the inception of Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). Recently, routine FT-ICR MS at the true cyclotron frequency has become a reality with the implementation of ICR cells with narrow aperture detection electrodes (NADEL). Here, we describe the development and implementation of the next generation of these cells, namely, a 2xNADEL ICR cell, which comprises four flat detect and four ∼45° cylindrical excite electrodes, enabling independent ion excitation and quadrupolar ion detection. The performance of the 2xNADEL ICR cell was evaluated on two commercial FT-ICR MS platforms, 10 T LTQ FT from Thermo Scientific and 9.4 T SolariX XR from Bruker Daltonics. The cells provided accurate mass measurements in the analyses of singly and multiply charged peptides (root-mean-square, RMS, mass error Δm/m of 90 ppb), proteins (Δm/m = 200 ppb), and petroleum fractions (Δm/m < 200 ppb). Due to the reduced influence of measured frequency on the space charge and external (trapping) electric fields, the 2xNADEL ICR cells exhibited stable performance in a wide range of trapping potentials (1-20 V). Similarly, in a 13 h rat brain MALDI imaging experiment, the RMS mass error did not exceed 600 ppb even for low signal-to-noise ratio analyte peaks. Notably, the same set of calibration constants was applicable to Fourier spectra in all pixels, reducing the need for recalibration at the individual pixel level. Overall, these results support further experimental development and fundamentals investigation of this promising technology.

Laboratory scale UV-visible degradation of acetamiprid in aqueous marketed mixtures - Structural elucidation of photoproducts and toxicological consequences

Acetamiprid is a neonicotinoid pesticide, which is extensively used on agricultural crops, but has a high toxic effect on beneficial insects and the human body. It is exposed to sunlight irradiation on crops but also in surface waters where it is found at a high level due to its resistance to common water treatments. The aim of the present work was to study the UV-visible photodegradation of acetamiprid, alone and in two marketed mixtures (Polysect Ultra SL® and Roseclear Ultra®). Ten photoproducts were characterized using LC-HR-MS/MS analysis. Photodegradation pathways were proposed based on the chemical structures of photoproducts and kinetic measurements; a matrix effect has been evidenced for commercial mixtures. Most photoproducts exhibit potential developmental toxicity twice higher than that of the parent compound. Regarding potential mutagenicity, all photoproducts are less toxic than acetamiprid. Estimated oral rat LD50 values show that the potential toxicities of photoproducts are similar or lower than that of acetamiprid. In vitro tests on Vibrio fischeri bacteria showed that the ecotoxicities of marketed mixtures are significantly higher than that of acetamiprid in aqueous solution; they slightly increase after UV-light exposure.

Photodegradation of benzisothiazolinone: Identification and biological activity of degradation products

The photodegradation of benzisothiazolinone was studied in water under UV-Vis irradiation and led to fourteen photoproducts. Chemical structures of these compounds were elucidated using GC-MS, LCMS/MS, and FT-ICR-MS experiments. Based on the chemical structures determined and their appearance order, a photo induced-degradation mechanism of benzisothiazolinone has been proposed, which combines isomerization, oxidation, hydroxylation, hydrolysis, and elimination processes. In silico tests on mutagenicity, Fathead minnow LC50 and oral rat LD50 were carried out to estimate the toxicity of the photoproducts. Compared with experimental data, the calculated oral rat LD50 values were found to be the most relevant and thus used for toxicity estimation. The photoproducts including a phenolic or a sulfino group or both functions were found potentially more toxic than benzisothiazolinone.

CT in planning transcatheter aortic valve implantation procedures and risk assessment

For surgical aortic valve replacement, the Society of Thoracic Surgeons score (STSS) is the reference standard for the prediction of operative risk. In transcatheter aortic valve implantation (TAVI) though, where the procedure itself is minimally invasive, the traditional risk assessment is supplemented by CTA. Through a consistent approach to the acquisition of high-quality images and the standardised reporting of annular measurements and adverse root and vascular features, patients at risk of complications can be identified. In turn, this may allow for a personalised procedural approach and treatment strategies devised to potentially reduce or mitigate this risk. This article provides a systematic and standardised approach to pre-procedural work-up with computed tomography angiography (CTA) and explores the current state of evidence and future areas of development in this rapidly developing field.

P3384Left atrial appendage pseudo-thrombus as an independent risk factor for ischaemic stroke in patients with non-valvular atrial fibrillation

Background

Left atrial appendage (LAA) pseudo-thrombus is a well recognised phenomenon in patients with atrial fibrillation (AF) undergoing cardiovascular CT (CCT). The clinical significance of LAA pseudothrombus on CCT, in those with non-valvular AF (NVAF) is unknown.

Objectives

To determine the association of LAA pseudo-thrombus in those with NVAF and ischaemic stroke.

Methods

216 consecutive patients with NVAF, referred for CCT (with both standard and 60-second delayed acquisitions) were assessed for the LAA pseudo-thrombus, LA and LAA dimensions and morphology, cardiovascular risk factors, treatment, and ischaemic stroke risk

Results

Mean age (±SD) was 65.0±10.6 years (range 32–89) and 70.8% were male. LAA pseudo-thrombus was present in 59/216 (27%) patients. Ischaemic stroke is more frequent with increasing age (OR 1.10 (95% confidence intervals (CI) 1.06, 1.16), p<0.0001), vascular disease (3.21 (1.18, 8.75) p=0.023), pseudo-thrombus on CCT (4.18 (1.97, 8.88) p<0.0001), cauliflour LAA morphology (4.93 (1.06, 22.09) p=0.042), and increased LAA ostial area: LAA tortuosity (4.64 (1.57, 13.71) p=0.006).

Age (1.09 (1.03, 1.15) p<0.0001), vascular disease (4.07 (1.19, 13.98) p=0.026), cauliflour LAA morphology (15.01 (2,93, 76.81) p=0.001) and pseudothrombus on CCT (3.62 (1.38, 9.50), p=0.009) were independently associated with ischaemic stroke. Pseudothrombus remained an independent risk factor even after CHA2DS2-VASc was included (3.21 (1.22, 8.41), p=0.018).

Conclusion

Pseudothrombus on CCT is a common finding in patients with NVAF and has a strong positive association with ischaemic stroke. Inclusion of pseudothrombus on CCT in risk assessment is additive to CHA2DS2-VASc in prediction of ischaemic stroke risk in patients with NVAF.

P3654Location of the coronary origins in transposition patients following anatomical repair: Implications for invasive coronary angiography and intervention

Background

Surgical repair of transposition of the great arteries (TGA) is most commonly via the arterial switch operation (ASO). This involves translocation of the aorta and pulmonary trunk, typically with anastomosis of the branch pulmonary arteries anteriorly (LeCompte manoeuvre) and re-implantation of the coronary arteries onto the posterior neo-aorta. As such, the position of the coronary ostia may differ from their expected locations.

Purpose

To use ECG-gated CT angiography to describe the anatomic position of coronary ostia in post-switch TGA patients guiding potential catheter interventions in this population.

Methods

All post ASO patients who underwent CT imaging between 2008–2018 were identified. Patients with complex anatomy such as double outlet right ventricle were excluded. The positions of the coronary ostia were measured in degrees from vertical on a double-oblique reconstruction in the aortic valve plane. Ostium positions were compared to those of patients with no congenital heart disease via Watson's two-sample test of homogeneity for circular data. Angular dispersion was compared between groups via the Wallraff test. P<0.05 indicated statistical significance.

Results

Of 206 adult patients with TGA and ASO followed in our adult congenital heart disease centre, 38 (18.4%) had CT imaging available for analysis during the study period (mean age 24±6.8, 75% male).

The control group consisted of 15 patients investigated for chest pain (mean age 54±15.1, 73% male). In the control group, the right and left coronary ostia arose at a mean angle of −19 and +125 degrees from vertical (figure 1a). This was significantly different to the mean ASO coronary ostia clustered at mean angles of −70 and +29 degrees from vertical (Watson p<0.001) (figure 1b, with stenosis at the left coronary anastomosis).

There was no significant difference in spread of left ostia (Rho 0.9 vs 0.99, p=0.12), but right ostia were significantly more variable in ASO patients than controls (0.71 vs 0.96, p=0.003).

Figure 1

Conclusions

Coronary ostial positions in the neo-aorta of post-ASO patients differ significantly from those of normal controls, with considerable variability, especially in right coronary position. CT can demonstrate coronary ostia in 3D space and derive appropriate tube angles to guide catheterisation in post-operative congenital cardiac patients, optimise catheter selection, reduce catheterisation tome, radiation and contrast dose.

P2243CTCA alone demonstrates superior diagnostic accuracy, prognostic utility and is less expensive than CTCA combined with subsequent multi-modality functional imaging in patients with ischaemic symptoms

Background

The evaluation of suspected ischaemic symptoms incorporates multi-modality anatomical and functional imaging tests. The 2016 update to the UK's NICE guidelines recommends CT coronary angiogram (CTCA) first line in patients without known coronary artery disease. Additive multi-modality functional imaging may provide synergistic diagnostic and prognostic information.

Purpose

To investigate the diagnostic accuracy, prognostic utility and cost of CTCA combined with subsequent multi-modality functional testing versus (vs) CTCA alone.

Methods

772 consecutive patients were referred to a single UK tertiary centre with symptoms suggestive of ischaemia. 657 individuals (“CTCA group”) underwent CTCA alone, and 115 individuals (“Combined group”) underwent CTCA and then either perfusion cardiac MRI (n=25), stress echocardiogram (n=16), or myocardial perfusion scintigraphy (n=74). Patients underwent invasive angiography (n=79) +/− revascularisation at the discretion of the referring clinician. All readers and operators were aware of previous imaging findings. Revascularised patients (n=52) were excluded from long term follow-up. The remaining patients were followed-up for a mean of 38.1±17.4 months and the incidence of major adverse cardiovascular events (MACE) recorded. Costs were derived from the NICE guidelines.

Results

Baseline characteristics were similar between groups. The Combined group underwent significantly more invasive angiograms than the CTCA group (29.6% vs 6.8%, p=0.0001) with no significant difference in the rate of revascularisation (73% vs 67%, p=0.72). Mean time from CTCA to angiogram was significantly longer in the Combined group (81.2 vs 38.1 days, p=0.0001). Both sensitivity and specificity were lower in the Combined group than in the CTCA group (sensitivity: 70% vs 93%, specificity: 75% vs 100%). The rate of long term MACE was significantly higher in the Combined group (8.7% vs 2.6%, p=0.0026). Multivariate analysis of CTCA and functional imaging findings found that CTCA-derived four vessel aggregate stenosis score (0–12) was the strongest predictor of MACE for the whole cohort (OR 4.4, p<0.0001), and also for those with negative functional tests (OR 3.9, p<0.0001). Per patient, a combined strategy was more expensive than CTCA alone (£1551 vs £368, p=0.0001).

CTCA and functional data vs outcomes

Conclusions

Combining multi-modality functional testing with CTCA increased costs but did not improve diagnostic accuracy or long term outcomes. Further reductions in both MACE and unnecessary invasive angiography are desirable; CT-derived functional data such as FFRCT may be implicated.

Image reconstruction in cardiovascular CT: Part 2 - Iterative reconstruction; potential and pitfalls

The use of IR in CT previously has been prohibitively complicated and time consuming, however improvements in computer processing power now make it possible on almost all CT scanners. Due to its potential to allow scanning at lower doses, IR has received a lot of attention in the medical literature and has become a successful commercial product. Its use in cardiovascular CT has been driven in part due to concerns about radiation dose and image quality. This manuscript discusses the various vendor permutations of iterative reconstruction (IR) in detail and critically appraises the current clinical research available on the various IR techniques used in cardiovascular CT.

Infrared Spectra of Deprotonated Dicarboxylic Acids: IRMPD Spectroscopy and Empirical Valence‐Bond Modeling

Experimental infrared multiple-photon dissociation (IRMPD) spectra recorded for a series of deprotonated dicarboxylic acids, HO₂ (CH₂ )_n CO 2 - (n=2-4), are interpreted using a variety of computational methods. The broad bands centered near 1600 cm^-1 can be reproduced neither by static vibrational calculations based on quantum chemistry nor by a dynamical description of individual structures using the many-body polarizable AMOEBA force field, strongly suggesting that these molecules experience dynamical proton sharing between the two carboxylic ends. To confirm this assumption, AMOEBA was combined with a two-state empirical valence-bond (EVB) model to allow for proton transfer in classical molecular dynamics simulations. Upon suitable parametrization based on ab initio reference data, the EVB-AMOEBA model satisfactorily reproduces the experimental infrared spectra, and the finite temperature dynamics reveals a significant amount of proton sharing in such systems.

Spectroscopy and Photodissociation of the Perfluorooctanoate Anion

Perfluorocarbons, a class of fully fluorinated compounds, are highly persistent and toxic pollutants that are receiving increasing attention due to their widespread environmental distribution. In this study, attention was focused on one compound in particular, namely, perfluorooctanoic acid (PFOA). The first investigation of the UV/VUV photochemistry of the PFOA anion in the gas phase by action spectroscopy of selected ions is reported. Two main relaxation channels were identified: photodissociation and photodetachment. Absolute cross sections for the individual observed processes were measured. DFT calculations and natural transition orbital analysis were carried out to help in the interpretation of the experimental results.

Molecular Characterization of Cloud Water Samples Collected at the Puy de Dôme (France) by Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

Cloud droplets contain dynamic and complex pools of highly heterogeneous organic matter, resulting from the dissolution of both water-soluble organic carbon in atmospheric aerosol particles and gas-phase soluble species, and are constantly impacted by chemical, photochemical, and biological transformations. Cloud samples from two summer events, characterized by different air masses and physicochemical properties, were collected at the Puy de Dôme station in France, concentrated on a strata-X solid-phase extraction cartridge and directly infused using electrospray ionization in the negative mode coupled with ultrahigh-resolution mass spectrometry. A significantly higher number (n = 5258) of monoisotopic molecular formulas, assigned to CHO, CHNO, CHSO, and CHNSO, were identified in the cloud sample whose air mass had passed over the highly urbanized Paris region (J1) compared to the cloud sample whose air mass had passed over remote areas (n = 2896; J2). Van Krevelen diagrams revealed that lignins/CRAM-like, aliphatics/proteins-like, and lipids-like compounds were the most abundant classes in both samples. Comparison of our results with previously published data sets on atmospheric aqueous media indicated that the average O/C ratios reported in this work (0.37) are similar to those reported for fog water and for biogenic aerosols but are lower than the values measured for aerosols sampled in the atmosphere and for aerosols produced artificially in environmental chambers.

UV-vis degradation of α-tocopherol in a model system and in a cosmetic emulsion-Structural elucidation of photoproducts and toxicological consequences

The UV-vis photodegradation of α-tocopherol was investigated in a model system and in a cosmetic emulsion. Both gas chromatography coupled with tandem mass spectrometry (GC-MS/MS) and high performance liquid chromatography coupled with ultrahigh resolution Fourier transform ion cyclotron resonance mass spectrometry (LC-UHR-MS) were used for photoproducts structural identification. Nine photoproduct families were detected and identified based on their mass spectra and additional experiments with α-tocopherol-d₉; phototransformation mechanisms were postulated to rationalize their formation under irradiation. In silico QSAR (Quantitative Structure Activity Relationship) toxicity predictions were conducted with the Toxicity Estimation Software Tool (T.E.S.T.). Low oral rat LD50 values of 466.78mgkg^-1 and 467.9mgkg^-1 were predicted for some photoproducts, indicating a potential toxicity more than 10 times greater that of α-tocopherol (5742.54mgkg^-1). In vitro assays on Vibrio fischeri bacteria showed that the global ecotoxicity of the α-tocopherol solution significantly increases with irradiation time. One identified product should contribute to this ecotoxicity enhancement since in silico estimations for D. magna provide a LC50 value 4 times lower than that of the parent molecule.

Photodegradation of cyprodinil under UV-visible irradiation - chemical and toxicological approaches

RATIONALE

Cyprodinil is a fungicide active on grapes, strawberries, tomatoes, and many other fruits. Under UV-visible irradiation, it undergoes photodegradation through various processes to form transformation products (TPs) whose structures and potential toxicities are unknown. The structures of the TPs were elucidated by comparing the photodegradation of cyprodinil and cyprodinil-D5 . The potential toxicities of these compounds were compared with that of cyprodinil.

METHODS

Aqueous solutions of cyprodinil were irradiated in a reactor equipped with a mercury vapor lamp. Analyses were carried out using high-performance liquid chromatography coupled to a quadrupole time-of-flight (QTOF) mass spectrometer or to a SolarixXR 9.4 Tesla Fourier transform (FT) mass spectrometer. High-resolution mass measurements, MS/MS and isotopic labeling experiments allowed structural elucidation of the cyprodinil TPs. The toxicities were estimated by three tests in silico using the TEST software and in vitro bioassays using Vibrio fischeri bacteria. These bioassays were carried out on irradiated solution for several exposure times and non-irradiated solutions.

RESULTS

The structures of 19 photoproducts were characterized by LC/HRMS/MS after 4 h of irradiation of a cyprodinil aqueous solution. The use of cyprodinil-D5 allowed the TPs to be characterized with more confidence. Knowing the structure of the TPs allows the estimation of their potential toxicities by in silico tests. Most of the photoproducts are potentially more toxic than the parent compound, based on the oral rat LD50 values, and most of them might induce more developmental and mutagenic toxicities. In vitro assays on Vibrio fischeri bacteria showed that the global ecotoxicity of the cyprodinil solution significantly increases with irradiation time.

CONCLUSIONS

Structures of photoproducts were characterized after irradiation of a cyprodinil aqueous solution combining LC/HRMS, LC/HRMS/MS and the use of a labeled compound. Their formations imply several photodegradation reactions, namely direct bond cleavages, cyclization, isomerization and hydroxylation. Most of the TPs exhibit a toxicity significantly higher than that of the parent molecule. Copyright © 2016 John Wiley & Sons, Ltd.

Transferring patients with Ebola by land and air: the British military experience

The Ebola epidemic of 2014/2015 led to a multinational response to control the disease outbreak. Assurance for British aid workers included provision of a robust treatment pathway including repatriation back to the UK. This pathway involved the use of both land and air assets to ensure that patients were transferred quickly, and safely, to a high-level isolation unit in the UK. Following a road move in Sierra Leone, an air transportable isolator (ATI) was used to transport patients for the flight and onward transfer to the Royal Free Hospital. There are several unique factors related to managing a patient with Ebola virus disease during prolonged evacuation, including the provision of care inside an ATI. These points are considered here along with an outline of the evacuation pathway.

Managing palpitations in the military patient

'Palpitations' include a broad range of symptoms relating to the perception of abnormal activity of the heart. They may reflect an underlying arrhythmia or a hyperawareness of normal cardiac activity caused by stress or anxiety. The challenge to a clinician assessing patients with palpitations is to assess the likely cause of symptoms, to stratify the individual patient risk and to choose the correct management strategy delivered with appropriate urgency. The young military population, subject to increased exposure to environmental stress, is at an increased risk of palpitations. Due to the distracting nature of this symptom and the frequently sudden and unheralded onset, a common consequence is medical downgrading. This article will provide a guide to assessing the heterogeneous group presenting with palpitations and how to both establish the cause and identify the correct treatment for each patient in a timely manner.

Isomerization of fenbuconazole under UV-visible irradiation - chemical and toxicological approaches

RATIONALE

Fenbuconazole is a fungicide commonly used for the protection of vineyards, vegetables and grain crops. Under UV-visible irradiation, it undergoes isomerization through various cyclization processes. Isomeric structures were elucidated by liquid chromatography/high-resolution multiple-stage mass spectrometry (LC/HR-MS(n) ) coupling. The potential toxicities of these isomers were estimated by in silico tests.

METHODS

Aqueous solutions of fenbuconazole and grapes treated with this fungicide were irradiated in a self-made reactor equipped with a mercury vapor lamp. Analyses were carried out using high-performance liquid chromatography (HPLC) coupled with Fourier transform ion cyclotron resonance mass spectrometry (FT-ICRMS). High-resolution m/z measurements, multiple-stage mass spectrometry and isotopic labeling experiments allowed structural elucidation of the isomers of fenbuconazole. In silico toxicity estimations were carried out using the T.E.S.T.

RESULTS

Seven isomers of fenbuconazole were detected after irradiation of the fungicide in aqueous solution; the major ones were also detected in the flesh of treated grapes irradiated under laboratory conditions. Elucidation of their chemical structures owing to high resolution measurements and multi-stage collision induced dissociation experiments allowed confirmation of photo-transformation pathways mainly dominated by cyclization processes. Photo-induced isomers exhibited higher potential toxicities than fenbuconazole for Daphnia magna and fathead minnow species.

CONCLUSIONS

UV-visible irradiation of fenbuconazole in aqueous solution and on grapes leads to the formation of isomers, all of which being potentially much more toxic than the parent fungicide.

Combining gas phase electron capture and IRMPD action spectroscopy to probe the electronic structure of a metastable reduced organometallic complex containing a non-innocent ligand

Gas-phase reduction of a Zn(ii) complex followed by IR spectroscopy shows that the incoming electron is localized on the metal rather than on the ligand.