Abdominal aortic junctional tourniquet (AAJT-S): a systematic review of utility in military practice.

INTRODUCTION: Haemorrhage is the leading cause of potentially survivable death on the battlefield. Despite overall improvement in battlefield mortality, there has been no improvement in survival following non-compressible torso haemorrhage (NCTH). The abdominal aortic junctional tourniquet-stabilised (AAJT-S) is a potential solution that may address this gap in improving combat mortality. This systematic review examines the evidence base for the safety and utility of the AAJT-S for prehospital haemorrhage control in the combat setting. METHODS: A systematic search of MEDLINE, Cumulated Index to Nursing and Allied Health Literature and Embase (inception to February 2022) was performed using exhaustive terms, in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guideline. The search was limited to English-language publications in peer-reviewed journals; grey literature was not included. Human, animal and experimental studies were included. Papers were reviewed by all authors to determine inclusion. Each study was assessed for level of evidence and bias. RESULTS: 14 studies met the inclusion criteria: 7 controlled swine studies (total n=166), 5 healthy human volunteer cases series (total n=251), 1 human case report and 1 mannikin study. The AAJT-S was demonstrated to be effective at cessation of blood flow when tolerated in healthy human and animal studies. It was easy to apply by minimally trained individuals. Complications were observed in animal studies, most frequently ischaemia-reperfusion injury, which was dependent on application duration. There were no randomised controlled trials, and the overall evidence base supporting the AAJT-S was low. CONCLUSIONS: There are limited data of safety and effectiveness of the AAJT-S. However, there is a requirement for a far-forward solution to improve NCTH outcomes, the AAJT-S is an attractive option and high-quality evidence is unlikely to be reported in the near future. Therefore, if this is implemented into clinical practice without a solid evidence base it will need a robust governance and surveillance process, similar to resuscitative endovascular balloon occlusion of the aorta, with regular audit of use.

High frequency UV-Vis sensors estimate error in riverine dissolved organic carbon load estimates from grab sampling.

High frequency ultraviolet - visible (UV-VIS) sensors offer a way of improving dissolved organic carbon (DOC) load estimates in rivers as they can be calibrated to DOC concentration. This is an improvement on periodic grab sampling, or the use of pumped sampling systems which store samples in-field before collection. We hypothesised that the move to high frequency measurements would increase the load estimate based on grab sampling due to systemic under-sampling of high flows. To test our hypotheses, we calibrated two sensors in contrasting catchments (Exe and Bow Brook, UK) against weekly grab sampled DOC measurements and then created an hourly time series of DOC for the two sites. Taking this measurement as a 'true' value of DOC load, we simulated 1,000 grab sampling campaigns at weekly, fortnightly and monthly frequency to understand the likely distribution of load and error estimates. We also performed an analysis of daily grab samples collected using a pumped storage sampling system with weekly collection. Our results show that: a) grab sampling systemically underestimates DOC loads and gives positively skewed distributions of results, b) this under-estimation and positive skew decreases with increasing sampling frequency, c) commonly used estimates of error in the load value are also systemically lowered by the oversampling of low, stable flows due to their dependence on the variance in the flow-weighted mean concentration, and d) that pumped storage systems may lead to under-estimation of DOC and over estimation of specific ultra-violet absorbance (SUVA), a proxy for aromaticity, due to biodegradation during storage.

A model of gross primary productivity based on satellite data suggests formerly afforested peatlands undergoing restoration regain full photosynthesis capacity after five to ten years.

Peatlands are an important terrestrial carbon store, but disturbance has resulted in the degradation of many peatland ecosystems and caused them to act as a net carbon source. Restoration work is being undertaken but monitoring the success of these schemes can be difficult and costly using traditional field-based methods. A landscape-scale alternative is to use satellite data to assess the condition of peatlands and to estimate gaseous carbon fluxes. In this study we used Moderate Resolution Imaging Spectroradiometer (MODIS) products to model Gross Primary Productivity (GPP) over peatland sites at various stages of restoration. We found that the MOD17A2H GPP product overestimates GPP modelled from data collected by eddy covariance towers situated at two ex-forestry sites undergoing restoration towards blanket bog at the Forsinard Flows RSPB reserve, Scotland, UK (one full year of data), and a near-natural Atlantic blanket bog site in Glencar, Ireland (ten-year data series). We calibrated a Temperature and Greenness (TG) model for the Forsinard sites and found it to be more accurate than the MODIS GPP product at local scale. We also found that inclusion of a wetness factor using the Normalised Difference Water Index (NDWI) improved inter-annual accuracy of the model. This TGWa (annual Temperature, Greenness and Wetness) model was then applied to six control sites comprising near-natural bog across the reserve, and to six sites on which restoration began between 1998 and 2006. GPP from 2005 to 2016 was estimated for each site using the model. The resulting modelled trends are positive at all six restored sites, increasing by approximately 5.5 g C/m2/yr every year since restoration began in the Forsinard Flows reserve. The results suggest that peatland sites undergoing restoration at Forsinard Flows reach the carbon assimilation potential of near-natural bog sites between 5 and 10 years after restoration was begun.

Sources of dissolved organic carbon (DOC) in a mixed land use catchment (Exe, UK).

Many catchment management schemes in the UK have focussed on peatland restoration to improve ecosystem services such as carbon sequestration, water quality and biodiversity. The effect of these schemes on dissolved organic carbon (DOC) flux is critical in understanding peatland carbon budgets as well as the implications for drinking water treatment. In many catchments, however, peatland areas are not the only source of DOC, meaning that their significance at the full catchment scale is unclear. In this paper we have evaluated the importance of different land uses as sources of DOC by combining three datasets obtained from the Exe catchment, UK. The first dataset comprises a weekly monitoring record at three sites for six years, the second, a monthly monitoring record of 25 sites in the same catchment for one year, and the third, an assessment of DOC export from litter and soil carbon stocks. Our results suggest that DOC concentration significantly increased from the peaty headwaters to the mixed land-use areas (ANOVA F = 12.52, p < 0.001, df = 2), leading to higher flux estimates at the downstream sites. We present evidence for three possible explanations: firstly, that poor sampling of high flows may lead to underestimation of DOC flux, second, that there are significant sources of DOC besides the peatland headwaters, and finally, that biological- and photo-degradation decreases the influence of upstream DOC sources. Our results provide evidence both for the targeting of catchment management in peatland areas as well as the need to consider DOC from agricultural and forested areas of the catchment.

The impact of climate change on the treatability of dissolved organic matter (DOM) in upland water supplies: a UK perspective.

Climate change in the UK is expected to cause increases in temperatures, altered precipitation patterns and more frequent and extreme weather events. In this review we discuss climate effects on dissolved organic matter (DOM), how altered DOM and water physico-chemical properties will affect treatment processes and assess the utility of techniques used to remove DOM and monitor water quality. A critical analysis of the literature has been undertaken with a focus on catchment drivers of DOM character, removal of DOM via coagulation and the formation of disinfectant by-products (DBPs). We suggest that: (1) upland catchments recovering from acidification will continue to produce more DOM with a greater hydrophobic fraction as solubility controls decrease; (2) greater seasonality in DOM export is likely in future due to altered precipitation patterns; (3) changes in species diversity and water properties could encourage algal blooms; and (4) that land management and vegetative changes may have significant effects on DOM export and treatability but require further research. Increases in DBPs may occur where catchments have high influence from peatlands or where algal blooms become an issue. To increase resilience to variable DOM quantity and character we suggest that one or more of the following steps are undertaken at the treatment works: a) 'enhanced coagulation' optimised for DOM removal; b) switching from aluminium to ferric coagulants and/or incorporating coagulant aids; c) use of magnetic ion-exchange (MIEX) pre-coagulation; and d) activated carbon filtration post-coagulation. Fluorescence and UV absorbance techniques are highlighted as potential methods for low-cost, rapid on-line process optimisation to improve DOM removal and minimise DBPs.

The management of open globe eye injuries: a discussion of the classification, diagnosis and management of open globe eye injuries.

Eye injuries occurred in 10% of UK military major trauma cases in Iraq and Afghanistan between 2004 and 2008, with 33% of these eye injuries open globe in nature(1). This article will consider the diagnosis, classification and management of open globe injuries in the role 1/ pre-hospital environment.

The role of a Royal Navy General Duties Medical Officer in helicopter assault force operations: a reflective article.

Royal Navy General Duties Medical Officers (RN GDMOs) are employed in land operations in Afghanistan in much the same way as British Army GDMOs. In this article the author explores how time with a Royal Marine Commando unit and completion of Commando training in parallel to thorough medical training are beneficial for the roles a RN GDMO is expected to undertake in Helicopter Assault Force Operations.

Conserved negatively charged residues are not required for ATP action at P2X(1) receptors.

The role of conserved negatively charged aspartic (D) and glutamic (E) acid residues within the ectodomain of the human P2X(1) receptor were examined by alanine substitution mutagenesis. Effects on ATP potency and cell surface localisation were assessed in Xenopus oocytes using the two electrode voltage clamp technique and cell surface biotinylation. Of the eleven residues tested no major shifts in ATP potency were observed with EC(50) values for ATP ranging from 0.8 to 4.3 microM (compared to 1 microM ATP for wild-type P2X(1) receptors). Peak current amplitudes for mutants D86A and D264A where reduced by approximately 90% due to a corresponding reduction in both total protein and cell surface expression. These results demonstrate that individual conserved negatively charged amino acids are not essential for ATP recognition by the human P2X(1) receptor and coordinated binding of the positive charge on magnesium complexed ATP by negatively charged amino acids is not required.

Comparison of sensory mid-palm studies to other techniques in carpal tunnel syndrome.

This prospective study was done to assess a technique of comparing Median-Ulnar sensory latency differences across the wrist (Sensory Palm [M-U]) to diagnose carpal tunnel syndrome (CTS) and to compare the relative sensitivities of other previously reported techniques: Median-Radial sensory difference (Sensory Thumb [M-R]), Median-Ulnar mixed palm difference (Mix Palm [M-U]) and Median-Ulnar sensory digit difference (Sensory Digits [M-U]). 90 Hands met the electrodiagnostic (EDX) criteria for mild CTS. The Sensory Thumb (M-R) was abnormal in 90% of the hands followed in order by Mix Palm (M-U) 61%, Sensory Digits (M-U) 42% and Sensory Palm (M-U) 33%. All differences were statistically significant (p < .01). Sensory Palm (M-U) did not significantly add to the diagnosis of CTS. The Sensory Thumb (M-R) was relatively the most sensitive followed by Mix Palm (M-R) was relatively the most sensitive followed by Mix Palm (M-U), Sensory Digits (M-U) and Sensory Palm (M-U).

Power spectral EEG analysis and EEG variability in obsessive-compulsive disorder.

Spectral EEG characteristics of thirteen patients with severe Obsessive-Compulsive Disorder (OCD) were investigated topographically. The finding of predominantly left posterior frontal to mid-temporal theta-2 is discussed in light of previous EEG studies and recent neuroradiologic findings.