A randomised clinical trial of ultrasound guided cannulation of difficult fistulae for dialysis access

Background: Arteriovenous fistulae (AVF) are preferred for dialysis access but require accurate cannulation for effective dialysis. Evidence supports improvements in cannulation and complication rates using ultrasound guidance (USG) in cannulating other sites. This mixed methods, randomised controlled trial aimed to assess effects of USG during AVF cannulation.Methods: Participants with difficult to cannulate AVF had each cannulation event randomised to USG or standard technique (no USG). The primary outcome was the incidence and number of additional needle passes. Secondary outcomes included: the incidence and number of additional skin punctures; time to achieve two needle cannulation; pain associated with cannulation; local complications. Qualitative outcomes were assessed using patient and staff questionnaires.Results: 32 participants had 346 cannulation events randomised (170 to USG and 176 to standard cannulation). USG resulted in a significant reduction in additional needle passes (72 vs 99 p=0.007) and additional skin punctures (10 vs 25 p=0.016.) but prolonged time to cannulation (p>0.001). There was no difference in pain score (p=0.705) or complications between groups. Questionnaires demonstrated that USG cannulation is acceptable to patients and staff. Conclusion: USG cannulation of AVF is more accurate and no more painful than non-image guided cannulation, but prolonged time to cannulation. Some of the excess time involved may be due to the trial being performed early in cannulating staff’s learning curve with the USG technique. Further work to elucidate which patients gain most benefit from USG cannulation and the effect of USG on cannulation complications and AVF patency is warranted

Mapping the effect of antimicrobial resistance in poultry production in Senegal: an integrated system dynamics and network analysis approach

The impact of antimicrobial resistance (AMR) extends beyond the farm-level to other stakeholders warranting the need for a collaborative approach to combat AMR while optimising production objectives and safeguarding human health. This study maps out the effect of AMR originating from poultry production in Senegal and highlights the entry points for interventions from stakeholders’ perspectives. A causal loop diagram (CLD) was developed following a group model building procedure with 20 stakeholders and integrated with network analysis by translating the CLD into an unweighted directed network. Results indicate that with an eigenvector centrality of 1, 0.85, and 0.74, the production cost, on-farm profit, and on-farm productivity, respectively are the most ranked influential variables driving the complexity of AMR in the poultry production system. Two reinforcing feedback loops highlight the dual benefits of improving on-farm productivity and increasing on-farm profit. However, one balancing feedback loop that revolves around the causal link between producers’ investment in qualified human resource personnel to ensure good farm management practices underline the financial implication of producers’ investment decisions. The findings provide precursory groundings for the development of a quantitative SD model, the formulation of intervention scenarios and ex-ante impact assessment of the cost-effectiveness of the interventions

Exploring SDA sensor architectures for the surveillance of geosynchronous spacecraft

Significant changes have taken place in the space domain over the past decade, with a growing number of emerging space-faring nations and commercial actors gaining access to the operational environment. The consequential diversification of space activities has brought about a need for a reassessment of space domain awareness (SDA) capabilities. Numerous states are developing their operational capability to undertake space-based activities, with potentially widespread ramifications for the safety of spacecraft. Rendezvous and proximity operations are becoming more prevalent in the geosynchronous (GSO) region for mission lifetime extension, active removal of debris, and satellite inspection, in all cases giving rise to novel challenges for SDA systems. What's more, there remains a largely uncharacterised population of small debris in the vicinity of the GSO region, uncovered by bespoke surveys with large aperture telescopes, and posing a significant risk to active satellites. In 2022, the UK Space Agency commissioned a study into the requirements and opportunities for SDA in the UK, carried out by CGI with support from the Global Network On Sustainability In Space (GNOSIS) and UKspace. The study highlighted research and development of sovereign sensors as one of its key recommendations, both to improve the UK's sensing capability and to contribute to closing gaps in global SDA capability. To this end, we explore the key requirements for future SDA sensor architectures, with a focus on ground-based electro-optical systems for the surveillance of spacecraft in the GSO region. Archival two-line element sets are used to simulate catalogued resident space objects (RSOs) passing through a grid of surveillance regions, tasked with monitoring the neighbourhoods of high-value assets in the vicinity of the geostationary belt, while the derived population from ESA's Meteoroid and Space Debris Terrestrial Environment Reference (MASTER) model is used as a basis for simulating the GSO debris field. We assess the observability of transiting RSOs from the vantage point of La Palma, Canary Islands, taking a variety of observational constraints into account, including the Earth's shadow, lunation, and the galactic plane. We examine the performance of the simulated surveillance regions in the context of comprehensive, yet cost-effective SDA provision. Estimated costs are weighed against important metrics for essential SDA tasks (e.g., catalogue maintenance , change detection, and conjunction analysis), such as the total traffic observed per night, the cadence of the observations, and the temporal coverage of registered RSOs. The results of the simulation are used to inform a discussion of key sensor architecture requirements for effective SDA of GSO assets, taking into consideration a combination of sensor characteristics (e.g., sensitivity, resolution, and wavelength band) and other factors (e.g., geographical placement, site quality, and observational strategy) influencing SDA capabilities. We provide a commentary on the advantages and limitations of the different architectures considered and conclude with a list of recommendations for the designs of future SDA systems for the protection of GSO spacecraft

PANC Study (Pancreatitis: A National Cohort Study): national cohort study examining the first 30 days from presentation of acute pancreatitis in the UK

Abstract Background Acute pancreatitis is a common, yet complex, emergency surgical presentation. Multiple guidelines exist and management can vary significantly. The aim of this first UK, multicentre, prospective cohort study was to assess the variation in management of acute pancreatitis to guide resource planning and optimize treatment. Methods All patients aged greater than or equal to 18 years presenting with acute pancreatitis, as per the Atlanta criteria, from March to April 2021 were eligible for inclusion and followed up for 30 days. Anonymized data were uploaded to a secure electronic database in line with local governance approvals. Results A total of 113 hospitals contributed data on 2580 patients, with an equal sex distribution and a mean age of 57 years. The aetiology was gallstones in 50.6 per cent, with idiopathic the next most common (22.4 per cent). In addition to the 7.6 per cent with a diagnosis of chronic pancreatitis, 20.1 per cent of patients had a previous episode of acute pancreatitis. One in 20 patients were classed as having severe pancreatitis, as per the Atlanta criteria. The overall mortality rate was 2.3 per cent at 30 days, but rose to one in three in the severe group. Predictors of death included male sex, increased age, and frailty; previous acute pancreatitis and gallstones as aetiologies were protective. Smoking status and body mass index did not affect death. Conclusion Most patients presenting with acute pancreatitis have a mild, self-limiting disease. Rates of patients with idiopathic pancreatitis are high. Recurrent attacks of pancreatitis are common, but are likely to have reduced risk of death on subsequent admissions. </jats:sec

Process evaluation of column flotation at Ergo

A dissertation submitted to the Faculty of Engineering, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Master of Science in Engineering. Johannesburg, 1990.The static Rand gold price has put pressure on the South African gold mines to improve efficiency. Superior metallurgical performance and lower costs attributed to column flotation prompted the construction of a pilot plant (238 millimetres by 10 metres) at ERGO, an Anglo American tailings retreatment plant [Abbreviated Abstract. Open document to view full version]MT201

Augmented Reality in Vascular and Endovascular Surgery: Scoping Review

BackgroundTechnological advances have transformed vascular intervention in recent decades. In particular, improvements in imaging and data processing have allowed for the development of increasingly complex endovascular and hybrid interventions. Augmented reality (AR) is a subject of growing interest in surgery, with the potential to improve clinicians’ understanding of 3D anatomy and aid in the processing of real-time information. This study hopes to elucidate the potential impact of AR technology in the rapidly evolving fields of vascular and endovascular surgery. ObjectiveThe aim of this review is to summarize the fundamental concepts of AR technologies and conduct a scoping review of the impact of AR and mixed reality in vascular and endovascular surgery. MethodsA systematic search of MEDLINE, Scopus, and Embase was performed in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. All studies written in English from inception until January 8, 2021, were included in the search. Combinations of the following keywords were used in the systematic search string: (“augmented reality” OR “hololens” OR “image overlay” OR “daqri” OR “magic leap” OR “immersive reality” OR “extended reality” OR “mixed reality” OR “head mounted display”) AND (“vascular surgery” OR “endovascular”). Studies were selected through a blinded process between 2 investigators (JE and AS) and assessed using data quality tools. ResultsAR technologies have had a number of applications in vascular and endovascular surgery. Most studies (22/32, 69%) used 3D imaging of computed tomography angiogram–derived images of vascular anatomy to augment clinicians’ anatomical understanding during procedures. A wide range of AR technologies were used, with heads up fusion imaging and AR head-mounted displays being the most commonly applied clinically. AR applications included guiding open, robotic, and endovascular surgery while minimizing dissection, improving procedural times, and reducing radiation and contrast exposure. ConclusionsAR has shown promising developments in the field of vascular and endovascular surgery, with potential benefits to surgeons and patients alike. These include reductions in patient risk and operating times as well as in contrast and radiation exposure for radiological interventions. Further technological advances are required to overcome current limitations, including processing capacity and vascular deformation by instrumentation

PTEN Phosphatase-Independent Maintenance of Glandular Morphology in a Predictive Colorectal Cancer Model System

Organotypic models may provide mechanistic insight into colorectal cancer (CRC) morphology. Three-dimensional (3D) colorectal gland formation is regulated by phosphatase and tensin homologue deleted on chromosome 10 (PTEN) coupling of cell division cycle 42 (cdc42) to atypical protein kinase C (aPKC). This study investigated PTEN phosphatase-dependent and phosphatase-independent morphogenic functions in 3D models and assessed translational relevance in human studies. Isogenic PTEN-expressing or PTEN-deficient 3D colorectal cultures were used. In translational studies, apical aPKC activity readout was assessed against apical membrane (AM) orientation and gland morphology in 3D models and human CRC. We found that catalytically active or inactive PTEN constructs containing an intact C2 domain enhanced cdc42 activity, whereas mutants of the C2 domain calcium binding region 3 membrane-binding loop (M-CBR3) were ineffective. The isolated PTEN C2 domain (C2) accumulated in membrane fractions, but C2 M-CBR3 remained in cytosol. Transfection of C2 but not C2 M-CBR3 rescued defective AM orientation and 3D morphogenesis of PTEN-deficient Caco-2 cultures. The signal intensity of apical phospho-aPKC correlated with that of Na+/H+ exchanger regulatory factor-1 (NHERF-1) in the 3D model. Apical NHERF-1 intensity thus provided readout of apical aPKC activity and associated with glandular morphology in the model system and human colon. Low apical NHERF-1 intensity in CRC associated with disruption of glandular architecture, high cancer grade, and metastatic dissemination. We conclude that the membrane-binding function of the catalytically inert PTEN C2 domain influences cdc42/aPKC-dependent AM dynamics and gland formation in a highly relevant 3D CRC morphogenesis model system

The effect of an aerobic exercise bout 24 h prior to each doxorubicin treatment for breast cancer on markers of cardiotoxicity and treatment symptoms: A RCT

Purpose: In rodents, a single exercise bout performed 24 h prior to a single doxorubicin treatment provides cardio-protection. This study investigated whether performing this intervention prior to every doxorubicin treatment for breast cancer reduced subclinical cardiotoxicity and treatment symptoms. Methods: Twenty-four women with early stage breast cancer were randomly assigned to perform a 30-min, vigorous-intensity treadmill bout 24 h prior to each of four doxorubicin-containing chemotherapy treatments or to usual care. Established echocardiographic and circulating biomarkers of subclinical cardiotoxicity, as well as blood pressure and body weight were measured before the first and 7–14 days after the last treatment. The Rotterdam symptom checklist was used to assess patient-reported symptoms. Results: The exercise and usual care groups did not differ in the doxorubicin-related change in longitudinal strain, twist, or cardiac troponin. However, the four total exercise bouts prevented changes in hemodynamics (increased cardiac output, resting heart rate, decreased systemic vascular resistance, p < 0.01) and reduced body weight gain, prevalence of depressed mood, sore muscles, and low back pain after the last treatment (p < 0.05) relative to the usual care group. No adverse events occurred. Conclusions: An exercise bout performed 24 h prior to every doxorubicin treatment did not have an effect on markers of subclinical cardiotoxicity, but had a positive systemic effect on hemodynamics, musculoskeletal symptoms, mood, and body weight in women with breast cancer. A single exercise bout prior to chemotherapy treatments may be a simple clinical modality to reduce symptoms and weight gain among women with breast cancer