Quantification of 3-dimensional structure and properties of flocculated natural suspended sediment

Natural sediment flocs are fragile and highly heterogeneous aggregates of biogenic and minerogenic material typically with high porosity and low density. In aquatic environments dominated by fine, cohesive or mixed sediments they can dominate suspended sediment flux. Consequently, monitoring and modelling the behaviour, transport and distribution of flocs is very important for many aquatic industries, maintenance of waterways and conservation and management of aquatic waterbodies. Mathematical models that predict the behaviour of flocs rely on the accurate assessments of the size, shape, density, porosity and fractal dimension of flocs. These inherently 3-dimensional (3D) characteristics are typically derived from 2-dimensional (2D) data, largely due to the challenges associated with sampling, capturing, imaging and quantifying these fragile aggregates. We have developed new volumetric microscopy techniques which can quantify 3D internal and external structures and characteristics of sediment flocs. Here, these techniques were applied to quantify the 3D size (volume), shape and fractal dimension of natural and artificial sediment flocs and compare them to standard 2D approaches. Our study demonstrates that 2D approaches are under-estimating shape complexity and over-estimating the size and mass settling flux of flocs by up to two orders of magnitude, and the discrepancy between 2D and 3D is most marked for natural, organic rich macroflocs. Our study has significant implications for estimations of sediment flux at local to global scales within in aquatic environments. These new data and approaches offer the potential to improve the current parameterisation of sediment transport models and to improve the accuracy of current field-monitoring techniques.

A surgical protocol for sinogenic brain abscess: the Oxford experience and a review of the literature

BACKGROUND

Rhinosinusitis-induced brain abscesses are rare but can result in devastating long-term sequalae and mortality; they require a high index of suspicion with early imaging to start early empiric parenteral antibiotic treatment covering aerobes and anaerobes.

METHODOLOGY

Our study was a retrospective analysis on 32 patients who were treated at Oxford University Hospitals for rhinosinusitis-induced brain abscess between February 2013 and June 2020.

RESULTS

Mean age of presentation was 45.83 for adults and 11.14 for children. Subdural collection was the most frequent abscess but 25% of patients had multiple sites of collection; the majority were in the frontal lobe. The most commonly identified pathogens were Streptococcus milleri group and Staphylococcus aureus; 93.75% of the patients were treated with combined Ceftriaxone and Metronidazole for an average of 8 weeks.

CONCLUSIONS

In our series most patients received also a prompt and aggressive surgical treatment with combined neurosurgical and ENT procedures in the majority; this was especially important in case of subdural empyema, Streptococcus milleri infection and direct intracranial spread of infection. More than half of the patients were treated with a single surgical procedure. Despite aggressive treatment, one third of patients experienced long-term neurological sequelae; there were no deaths.

Persistence and removal of trace organic compounds in centralized and decentralized wastewater treatment systems

The persistence of trace organic chemicals in treated effluent derived from both centralized wastewater treatment plants (WWTPs) and decentralized wastewater treatment systems (DEWATS) is of concern due to their potential impacts on human and ecosystem health. Here, we utilize non-targeted analysis (NTA) with comprehensive two-dimensional gas chromatography coupled with time of flight mass spectrometry (GC × GC/TOF-MS) to conduct an evaluation of the common persistent and removed compounds found in two centralized WWTPs in the USA and South Africa and one DEWATS in South Africa. Overall, removal efficiencies of chemicals were similar between the treatment plants when they were compared according to the number of chemical features detected in the influents and effluents of each treatment plant. However, the DEWATS treatment train, which has longer solids retention and hydraulic residence times than both of the centralized WWTPs and utilizes primarily anaerobic treatment processes, was able to remove 13 additional compounds and showed a greater decrease in normalized peak areas compared to the centralized WWTPs. Of the 111 common compounds tentatively identified in all three influents, 11 compounds were persistent in all replicates, including 5 compounds not previously reported in effluents of WWTPs or water reuse systems. There were no significant differences among the physico-chemical properties of persistent and removed compounds, but significant differences were observed among some of the molecular descriptors. These results have important implications for the treatment of trace organic chemicals in centralized and decentralized WWTPs and the monitoring of new compounds in WWTP effluent.

Time to definitive care within major trauma networks in England

BACKGROUND

Significant mortality improvements have been reported following the implementation of English trauma networks. Timely transfer of seriously injured patients to definitive care is a key indicator of trauma network performance. This study evaluated timelines from emergency service (EMS) activation to definitive care between 2013 and 2016.

METHODS

An observational study was conducted on data collected from the UK national clinical audit of major trauma care of patients with an Injury Severity Score above 15. Outcomes included time from EMS activation to: arrival at a trauma unit (TU) or major trauma centre (MTC); to CT; to urgent surgery; and to death.

RESULTS

Secondary transfer was associated with increased time to urgent surgery (median 7·23 (i.q.r. 5·48-9·28) h versus 4·37 (3·00-6·57) h for direct transfer to MTC; P < 0·001) and an increased crude mortality rate (19·6 (95 per cent c.i. 16·9 to 22·3) versus 15·7 (14·7 to 16·7) per cent respectively). CT and urgent surgery were performed more quickly in MTCs than in TUs (2·00 (i.q.r. 1·55-2·73) versus 3·15 (2·17-4·63) h and 4·37 (3·00-6·57) versus 5·37 (3·50-7·65) h respectively; P < 0·001). Transfer time and time to CT increased between 2013 and 2016 (P < 0·001). Transfer time, time to CT, and time to urgent surgery varied significantly between regional networks (P < 0·001).

CONCLUSION

Secondary transfer was associated with significantly delayed imaging, delayed surgery, and increased mortality. Key interventions were performed more quickly in MTCs than in TUs.

1 vs 3 days laparoscopic suturing courses: is it feasible to design a valid training curriculum?

BACKGROUND

Laparoscopic skills are unlikely to be achieved exclusively in the operating theatre, so simulation training has become mandatory to acquire specific psychomotor skills to be merged in a more complex procedure.

OBJECTIVE

To compare 3-day vs. 1-day laparoscopic suturing courses and to better address participants' needs according to their level of experience.

METHODS

Observational cohort study conducted between January 2017 and December 2018 including 107 participants amongst which 61 attended a 3-day and 46 the 1-day suturing course.

RESULTS

Data analysis showed no significant difference in the pre-test suturing scores between the two groups. On each course, when comparing the pre- and post-tests results, the participants reached a statistically significant improvement in both precision and knotting score (p< 0.01). However, when comparing the two types of courses, the data showed a better performance in the post-session test for those attending the 3-day course (p<0.05), as well as a higher mean score improvement (4.7 vs. 2.8; p<0.05) and time needed to complete exercises (-270s vs. -150s; p<0.05). Furthermore, grouping the participants according to their experience, the experts achieved a significantly better improvement attending the 3-day course, when compared to the beginners.

CONCLUSIONS

Both 3 and 1-day course are successful in improving laparoscopic suturing skills regardless of the participant's experience. However experienced participants benefit more from a longer course while the 1-day one should be dedicated to pre-surgical competences acquisition.

Application of Next Generation Sequencing for Diagnostic Testing of Tree Fruit Viruses and Viroids

Conventional detection of viruses and virus-like diseases of plants is accomplished using a combination of molecular, serological, and biological indexing. These are the primary tools used by plant virologists to monitor and ensure trees are free of known viral pathogens. The biological indexing assay, or bioassay, is considered to be the "gold standard" as it is the only method of the three that can detect new, uncharacterized, or poorly characterized viral disease agents. Unfortunately, this method is also the most labor intensive and can take up to three years to complete. Next generation sequencing (NGS) is a technology with rapidly expanding possibilities including potential applications for the detection of plant viruses. In this study, comparisons are made between tree fruit testing by conventional and NGS methods, to demonstrate the efficacy of NGS. A comparison of 178 infected trees, many infected with several viral pathogens, demonstrated that conventional and NGS were equally capable of detecting known viruses and viroids. Comparable results were obtained for 170 of 178 of the specimens. Of the remaining eight specimens, some discrepancies were observed between viruses detected by the two methods, representing less than 5% of the specimens. NGS was further demonstrated to be equal or superior for the detection of new or poorly characterized viruses when compared with a conventional bioassay. These results validated both the effectiveness of conventional virus testing methods and the use of NGS as an additional or alternative method for plant virus detection.

Morphological Measurements of the Proximal Interphalangeal Joint

The morphology of the proximal interphalangeal joint was determined using a photographic technique. The head of the proximal phalanx, viewed end on, has a complex trapezoid appearance characteristic for each named digit. The asymmetric condyles diverge from one another and are separated by an intercondylar groove that increases in depth from the dorsal to the palmar surface. Saggital sections of the head of the proximal phalanx are not circular, but, sections taken in the plane of maximum dimensions of the condyle are circular with a radius of curvature of approximately one half of the height of the condyles.

The articular surface of the base of the middle phalanx is not circular in outline in either the saggital or coronal plane. In coronal sections the articular surface is biconcave convex with a prominent median ridge separating the two adjacent concave articular surfaces.

The implications of this varied morphology on implant design are discussed.

Emerging therapies for the treatment of relapsed or refractory follicular lymphoma

With no treatment standard having been established for relapsed and refractory follicular lymphoma, a number of therapeutic approaches are used in Canada. In patients who relapse early or who eventually become resistant to subsequent treatment, prognosis is poor, and new approaches are needed. A number of novel therapies are being examined in this setting, including monoclonal antibodies, immunoconjugates, immunomodulatory agents, and signal transduction inhibitors. With the body of evidence for those emerging therapies accumulating and the standard upfront treatment changing from rituximab and chop (cyclophosphamide-doxorubicin-vincristine-prednisone) or rituximab and cvp (cyclophosphamide-vincristine-prednisone) to bendamustine and rituximab, treatment decisions in the relapsed and refractory setting have become more complex. The choice of subsequent treatment must consider type of upfront treatment; duration of remission; and patient-related factors such as age, comorbidities, and treatment preferences. This paper summarizes the evidence for novel therapies and proposes recommendations for subsequent treatment options by remission duration after induction and maintenance.

Traumatic brain injury in England and Wales: prospective audit of epidemiology, complications and standardised mortality

OBJECTIVES

To provide a comprehensive assessment of the management of traumatic brain injury (TBI) relating to epidemiology, complications and standardised mortality across specialist units.

DESIGN

The Trauma Audit and Research Network collects data prospectively on patients suffering trauma across England and Wales. We analysed all data collected on patients with TBI between April 2014 and June 2015.

SETTING

Data were collected on patients presenting to emergency departments across 187 hospitals including 26 with specialist neurosurgical services, incorporating factors previously identified in the Ps14 multivariate logistic regression (Ps14ⁿ) model multivariate TBI outcome prediction model. The frequency and timing of secondary transfer to neurosurgical centres was assessed.

RESULTS

We identified 15 820 patients with TBI presenting to neurosurgical centres directly (6258), transferred from a district hospital to a neurosurgical centre (3682) and remaining in a district general hospital (5880). The commonest mechanisms of injury were falls in the elderly and road traffic collisions in the young, which were more likely to present in coma. In severe TBI (Glasgow Coma Score (GCS) ≤8), the median time from admission to imaging with CT scan is 0.5 hours. Median time to craniotomy from admission is 2.6 hours and median time to intracranial pressure monitoring is 3 hours. The most frequently documented complication of severe TBI is bronchopneumonia in 5% of patients. Risk-adjusted W scores derived from the Ps14ⁿ model indicate that no neurosurgical unit fell outside the 3 SD limits on a funnel plot.

CONCLUSIONS

We provide the first comprehensive report of the management of TBI in England and Wales, including data from all neurosurgical units. These data provide transparency and suggests equity of access to high-quality TBI management provided in England and Wales.