Engineering Enzymes for Environmental Sustainability.

The development and implementation of sustainable catalytic technologies is key to delivering our net-zero targets. Here we review how engineered enzymes, with a focus on those developed using directed evolution, can be deployed to improve the sustainability of numerous processes and help to conserve our environment. Efficient and robust biocatalysts have been engineered to capture carbon dioxide (CO2 ) and have been embedded into new efficient metabolic CO2 fixation pathways. Enzymes have been refined for bioremediation, enhancing their ability to degrade toxic and harmful pollutants. Biocatalytic recycling is gaining momentum, with engineered cutinases and PETases developed for the depolymerization of the abundant plastic, polyethylene terephthalate (PET). Finally, biocatalytic approaches for accessing petroleum-based feedstocks and chemicals are expanding, using optimized enzymes to convert plant biomass into biofuels or other high value products. Through these examples, we hope to illustrate how enzyme engineering and biocatalysis can contribute to the development of cleaner and more efficient chemical industry.

Scalp-Mounted Electrical Impedance Tomography of Cerebral Hemodynamics.

An Electrical Impedance Tomography (EIT) system has been developed for dynamic three-dimensional imaging of changes in conductivity distribution in the human head, using scalp-mounted electrodes. We attribute these images to changes in cerebral perfusion. At 100 frames per second (fps), voltage measurement is achieved with full-scale signal-to-noise ratio of 105 dB and common-mode rejection ratio > 90 dB. A novel nonlinear method is presented for 3-D imaging of the difference in conductivity distribution in the head, relative to a reference time. The method achieves much reduced modelling error. It successfully localizes conductivity inclusions in experimental and simulation tests, where previous methods fail. For > 50 human volunteers, the rheoencephalography (REG) waveform is observed in EIT voltage measurements for every volunteer, with peak-to-peak amplitudes up to approx. 50 µVrms. Images are presented of the change in conductivity distribution during the REG/cardiac cycle, at 50 fps, showing maximum local conductivity change of approx. 1% in grey/white matter. A total of 17 tests were performed during short (typically 5s) carotid artery occlusions on 5 volunteers, monitored by Transcranial Doppler ultrasound. From EIT measurements averaged over complete REG/cardiac cycles, 13 occlusion tests showed consistently decreased conductivity of cerebral regions on the occluded side, and increased conductivity on the opposite side. The maximum local conductivity change during occlusion was approx. 20%. The simplicity of the carotid artery intervention provides a striking validation of the scalp-mounted measurement system in imaging cerebral hemodynamics, and the REG images indicate its unique combination of sensitivity and temporal resolution.

Characterising the arthroplasty in spondyloarthropathy in a large cohort of eighty-seven patients with alkaptonuria.

Arthroplasty in the spondyloarthropathy (SPOND) of alkaptonuria (AKU) in incompletely characterised. The aim was to improve the understanding of arthroplasty in AKU through a study of patients attending the National Alkaptonuria Centre (NAC). Eighty-seven patients attended the NAC between 2007 and 2020. Seven only attended once. Fifty-seven attended more than once and received nitisinone 2 mg daily. Twenty-three attended at least twice without receiving nitisinone. Assessments including questionnaire analysis eliciting details of arthroplasty and other surgical treatments for SPOND, 18 FPETCT and CT densitometry at the neck of hip and lumbar spine, as well as photographs of the eyes and ears were acquired from patients attending the National Alkaptonuria Centre (NAC) at baseline when 2 mg nitisinone was commenced, and yearly thereafter. Photographs were scored to derive ochronosis scores. Blood and urine samples were collected for chemical analyses. The prevalence of arthroplasty was 36.8%, similar in males and females, occurring especially in the knees, hips and shoulders. Multiple arthroplasties were found in 29 patients (33.3%) in this cohort. Incident arthroplasty was 6.5% in the nitisinone group and 7.1% in the no-nitisinone group. Incident arthroplasty was 11.3% in the group with baseline arthroplasty and 3.51% in the group without. A strong association of arthroplasty with SPOND (R = 0.5; P << .0001) and ochronosis (R = 0.54; P < .0001) was seen. Nitisinone had no significant effect on incident arthroplasty. Arthroplasty due to ochronosis and SPOND is common in AKU. Nitisinone decreased ochronosis but had no effect on arthroplasty in this cohort.

Single Use Instruments for Implanting a Contemporary Total Knee Arthroplasty System Are Accurate, Efficient, and Safe.

BACKGROUND: Single use instruments (SUI) is a potential mechanism to improve efficiency and reduce cost in total knee arthroplasty (TKA). New technology requires patient safety and surgical accuracy. A multi-center study of SUI vs reusable mechanical instrumentation (RUI) for a TKA system compared implant placement accuracy and operating room (OR) efficiency. METHODS: Four surgeons implanted 88 primary TKAs, N = 44 RUI and N = 44 SUI. Accuracy was measured radiographically at 3 months. The primary endpoint was non-inferiority of absolute value of mechanical axis alignment. Radiographic endpoints, OR times, and adverse events were also evaluated. RESULTS: Seventy-five subjects completed the study (41 SUI/34 RUI). The primary endpoint non-inferiority of SUI vs RUI was met, with no significant difference between SUI and RUI in most radiographic parameters (distal femoral varus-valgus, proximal tibial varus-valgus, tibial slope, or subjects within 3° of target); there was a slight difference in femoral component flexion angle (P = .015). SUI and RUI mean (SD) OR set-up times were 18.8 (10.03) and 26.7 (6.93) (P <.001), and surgical times (first incision to last stitch) were 64.6 (16.95) and 60.5 (19.01) (P = .295), respectively. Differences in OR clean-down and anesthesia were not significant. There were no revisions, and there was no significant difference in the number of reported adverse events. CONCLUSION: SUI resulted in similar accuracy of implant placement to RUI with decreased OR set-up time and no increase in adverse events. These results support the safety and efficacy of SUI for performing TKA. Further analysis of potential economic and technical advantages is warranted.

Closed Incisional Negative Pressure Wound Therapy Sponge Width and Tension Off-Loading: A Laboratory Model.

Closed incisional negative pressure wound therapy (ciNPWT) has become commonplace in surgery. One mechanism ciNPWT may prevent incision site complications is by off-loading tension. This study aimed to find what width sponge using ciNPWT provides the most tension off-loading.A model was designed to test tension off-loading of a wound using ciNPWT. An incision was made in an anatomy model and closed with single stitch at the central axis. Force was applied tangentially using a force gauge at a steady rate until the wound dehisced at a peak force indicated by the 5-0 suture breaking. This was repeated 10 times for the following 4 trials: no ciNPWT and ciNPWT sponges cut a 3-, 6-, and 9-cm widths with 125 mm Hg of negative pressure.The mean peak force to dehisce the wound without ciNPWT was the lowest, 28.7 N. The mean force for the ciNPWT trials was 43.0, 38.7, and 36.4 N for V.A.C. sponges of 3, 6, and 9 cm in width, respectively. There was a statically significant difference among all the trials using one-way analysis of variance with Tukey posttest analysis with a P value of less than 0.0001.Closed incisional negative pressure wound therapy was shown to increase peak force required to dehisce an incision of up to 49.7% compared with closure without. There is an inverse relationship with sponge width and tension off-loading. The smaller the sponge, the more tension is off-loaded across the incision. Closed incisional negative pressure wound therapy with a 3-cm-wide sponge required the greatest peak force for dehiscence.

The Medium-Term Survival Analysis of an All-Polyethylene Tibia in a Single-Series Cohort of Over 1000 Knees.

BACKGROUND: Total knee arthroplasty is a successful elective orthopedic procedure with an increasing number being undertaken. Original knee arthroplasties used an all-polyethylene tibia; however, with concerns over tibial loosening, the trend moved toward the metal-backed variety. Modern designs providing more conformity and changes in manufacturing of the polyethylene make it an equivalent but cheaper option. METHODS: We analyzed the medium-term outcome in 1092 patients with an all-polyethylene tibial component in their total knee arthroplasty. RESULTS: Twenty-six patients had further surgery on their knee for a variety of reasons. Assessing reoperation for any reason, the 7-year survival rate was 96.96% with an overall infection rate of 0.37%. Seven-year survival analysis using aseptic loosening as a criteria was 99.28%. Both the Short Form 12 physical score and Western Ontario and McMaster Universities Osteoarthritis Index score significantly improved and was sustained at 7 years. Body mass did not correlate to either outcomes or complications. CONCLUSION: An all-polyethylene tibia in a total knee arthroplasty has good outcome data and high patient satisfaction with good survivorship in the medium term, coupled with potential cost-saving benefits.

Combining Electromagnetic Spectroscopy and Ground-Penetrating Radar for the Detection of Anti-Personnel Landmines.

Dual mode detectors combining metal detection and ground-penetrating radar are increasingly being used during humanitarian demining operations because of their ability to discriminate metal clutter. There are many reports in the academic literature studying metal detector and ground-penetrating radar systems individually. However, the combination of these techniques has received much less attention. This paper describes the development of a novel dual modality landmine detector, which integrates spectroscopic metal detection with ground-penetrating radar. This paper presents a feature-level sensor fusion strategy based on three features extracted from the two sensors. This paper shows how the data from the two components can be fused together to enrich the feedback to the operator. The algorithms presented in this paper are targeted at automating the location of buried, visibly obscured objects; however, the system described is also capable of collecting information which could also be used for the potential classification of such items.

An integrated semiconductor device enabling non-optical genome sequencing.

The seminal importance of DNA sequencing to the life sciences, biotechnology and medicine has driven the search for more scalable and lower-cost solutions. Here we describe a DNA sequencing technology in which scalable, low-cost semiconductor manufacturing techniques are used to make an integrated circuit able to directly perform non-optical DNA sequencing of genomes. Sequence data are obtained by directly sensing the ions produced by template-directed DNA polymerase synthesis using all-natural nucleotides on this massively parallel semiconductor-sensing device or ion chip. The ion chip contains ion-sensitive, field-effect transistor-based sensors in perfect register with 1.2 million wells, which provide confinement and allow parallel, simultaneous detection of independent sequencing reactions. Use of the most widely used technology for constructing integrated circuits, the complementary metal-oxide semiconductor (CMOS) process, allows for low-cost, large-scale production and scaling of the device to higher densities and larger array sizes. We show the performance of the system by sequencing three bacterial genomes, its robustness and scalability by producing ion chips with up to 10 times as many sensors and sequencing a human genome.

Influence of Fishmeal-Free Diets on Microbial Communities in Atlantic Salmon (Salmo salar) Recirculation Aquaculture Systems.

UNLABELLED: Reliance on fishmeal as a primary protein source is among the chief economic and environmental concerns in aquaculture today. Fishmeal-based feeds often require harvest from wild fish stocks, placing pressure on natural ecosystems and causing price instability. Alternative diet formulations without the use of fishmeal provide a potential solution to this challenge. Although the impact of alternative diets on fish performance, intestinal inflammation, palatability, and gut microbiota has been a topic of recent interest, less is known about how alternative feeds impact the aquaculture environment as a whole. The recent focus on recirculating aquaculture systems (RAS) and the closed-containment approach to raising food fish highlights the need to maintain stable environmental and microbiological conditions within a farm environment. Microbial stability in RAS biofilters is particularly important, given its role in nutrient processing and water quality in these closed systems. If and how the impacts of alternative feeds on microbial communities in fish translate into changes to the biofilters are not known. We tested the influence of a fishmeal-free diet on the microbial communities in RAS water, biofilters, and salmon microbiomes using high-throughput 16S rRNA gene V6 hypervariable region amplicon sequencing. We grew Atlantic salmon (Salmo salar) to market size in six replicate RAS tanks, three with traditional fishmeal diets and three with alternative-protein, fishmeal-free diets. We sampled intestines and gills from market-ready adult fish, water, and biofilter medium in each corresponding RAS unit. Our results provide data on how fish diet influences the RAS environment and corroborate previous findings that diet has a clear influence on the microbiome structure of the salmon intestine, particularly within the order Lactobacillales (lactic acid bacteria). We conclude that the strong stability of taxa likely involved in water quality processing regardless of diet (e.g., Nitrospira) may further alleviate concerns regarding the use of alternative feeds in RAS operations. IMPORTANCE: The growth of the aquaculture industry has outpaced terrestrial livestock production and wild-capture fisheries for over 2 decades, currently producing nearly 50% of all seafood consumed globally. As wild-capture fisheries continue to decline, aquaculture's role in food production will grow, and it will produce an estimated 62% of all seafood consumed in 2020. A significant environmental concern of the industry is the reliance on fishmeal as a primary feed ingredient, as its production still requires harvest from wild fisheries. Our study adds to the growing body of literature on the feasibility of alternative, fishmeal-free diets. Specifically, we asked how fishmeal-free diets influence microbial communities in recirculating salmon farms. Unlike previous studies, we extended our investigation beyond the microbiome of the fish itself and asked how alterative diets influence microbial communities in water and critical biofilter habitats. We found no evidence for adverse effects of alternative diets on any microbial habitat within the farm.

Automaticity in fast lexical decision sequential effects: much like telling left from right.

Successive lexical decisions have shown sequential effects where faster word responses and slower nonword responses follow the same versus different prior response. To date, explanations of these effects have been based on processes specific to discriminating words from nonwords. However, a more parsimonious explanation is possible, based on generic choice processes that apply even to left/right discriminations. Under conditions that promote automaticity, this explanation distinctly predicts equal facilitation by response repetition for words and nonwords. This hypothesis was here tested in an experiment involving 82 participants completing 850-trial blocks of lexical decision with a 100 ms response-stimulus interval-a much faster rate of choice succession than previously used-and including a factor of word/nonword discriminability so as to further test the applicability of choice-specific processes. Distinct from earlier findings, sequential effects were found to be identical in sign and substance for words and nonwords. This reliably occurred as facilitation by repetition across the decile distribution of response-times, across high and low levels of word/nonword discriminability, within each block of the run, and in interaction with higher-order sequential effects involving up to four prior trials. The main effect of facilitation by repetition at the second-order was particularly strong, being equal in effect-size to the interactive effect of the word/nonword factor and word/nonword discriminability (η (2) = 0.61). Hence, generic choice processes appeared to be sufficient to produce lexical decision sequential effects, independently of choice-specific processes. The findings particularly suggested a primary role for automatic response-facilitation, with accuracy-monitoring and expectancy contributing to higher-order effects. The further role of choice-specific processes in these and other findings, and the utility of lexical decision in studying generic choice processes, are discussed.

The bronchiectasis severity index. An international derivation and validation study.

RATIONALE: There are no risk stratification tools for morbidity and mortality in bronchiectasis. Identifying patients at risk of exacerbations, hospital admissions, and mortality is vital for future research. OBJECTIVES: This study describes the derivation and validation of the Bronchiectasis Severity Index (BSI). METHODS: Derivation of the BSI used data from a prospective cohort study (Edinburgh, UK, 2008-2012) enrolling 608 patients. Cox proportional hazard regression was used to identify independent predictors of mortality and hospitalization over 4-year follow-up. The score was validated in independent cohorts from Dundee, UK (n = 218); Leuven, Belgium (n = 253); Monza, Italy (n = 105); and Newcastle, UK (n = 126). MEASUREMENTS AND MAIN RESULTS: Independent predictors of future hospitalization were prior hospital admissions, Medical Research Council dyspnea score greater than or equal to 4, FEV1 < 30% predicted, Pseudomonas aeruginosa colonization, colonization with other pathogenic organisms, and three or more lobes involved on high-resolution computed tomography. Independent predictors of mortality were older age, low FEV1, lower body mass index, prior hospitalization, and three or more exacerbations in the year before the study. The derived BSI predicted mortality and hospitalization: area under the receiver operator characteristic curve (AUC) 0.80 (95% confidence interval, 0.74-0.86) for mortality and AUC 0.88 (95% confidence interval, 0.84-0.91) for hospitalization, respectively. There was a clear difference in exacerbation frequency and quality of life using the St. George's Respiratory Questionnaire between patients classified as low, intermediate, and high risk by the score (P < 0.0001 for all comparisons). In the validation cohorts, the AUC for mortality ranged from 0.81 to 0.84 and for hospitalization from 0.80 to 0.88. CONCLUSIONS: The BSI is a useful clinical predictive tool that identifies patients at risk of future mortality, hospitalization, and exacerbations across healthcare systems.

Empathy and integrative thinking: Talmudic paradigms for the essentials of a medical interview.

Intentional empathy and integrative thinking are essential elements of a medical interview. Yet the repetitive, sometimes monotonous, nature of medical practice can compromise their achievement. Emotional and intellectual fatigue may lead to clouded observation with diagnostic errors resulting. In spite of a long extant pedagogy of teaching interviewing techniques and creative mnemonics, hurdles remain and significant miscues continue. The challenge is one of surmounting these obstacles and of finding 'new' ways to perform 'old' tasks. It is to do what we already know to do but somehow do not. In the essay which follows, two Talmudic legends are identified and discussed as paradigms for empathy and integrative thinking. They are offered as 'literary mnemonics' for potential use in physician-patient encounters. The legends are linked to the insights of contemporary scholars including Jerome Groopman, Danielle Ofri, Roger Martin and others who have considered concepts of cognition, emotion, empathy, 'opposable mind' and integrative thinking in medical and non-medical settings.

Nonoperative Treatment of Dupuytren's Contracture: The Use of Ultrasound Imaging to Assess Efficacy.

Objective: We have used ultrasound imaging technology to objectively demonstrate changes in the degree and quality of diseased fascia in patients with Dupuytren's disease treated nonoperatively with therapeutic splinting and tissue mobilization. Materials and Methods: Measurement of active proximal interphalangeal and metacarpophalangeal joint extension along with ultrasound elastography imaging of the fascia was performed prior to, and 6 months after, the initiation of therapy. Results: Improvement in active joint extension over the course of therapy was associated with a consistent decrease in the radiologic dimensions of the diseased fascia in combination with qualitative changes in its composition. Conclusion: The use of a simple orthosis and soft tissue mobilization techniques have a quantifiable effect on the degree of deformity and the quantity and quality of contracted fascia in Dupuytren's disease, and would appear to have a role in the management of mild to moderate presentations of the disease when enzymatic or surgical interventions may not be practical.

Tibial polyethylene post fractures at ten-years in a bicruciate stabilised (BCS) total knee arthroplasty design.

INTRODUCTION: This short paper reports a potential emerging mode of failure in three patients with a bicruciate stabilised (BCS) total knee arthroplasty. METHODS: Three patients presented to our institution with late instability ten years after undergoing total knee arthroplasty (Journey BCS) and were asymptomatic up to this point. Retrieval analysis was performed by an external body commissioned by the NHS and all three cases were reported to the UK Medicines and Healthcare Products Regulatory Agency (MHRA). RESULTS: Two patients were revised through simple exchange with a polyethylene tibial insert. One patient underwent a full revision of femoral and tibial components. Intra-operative findings revealed that the polyethylene post had fractured in an identical manner in all three cases. Retrieval analysis demonstrated posterior impingement and wear of the polyethylene post resulting in fatigue failure. CONCLUSIONS: This short paper highlights a potential emerging mode of failure with Journey BCS that requires wider dissemination to raise awareness among surgeons and calls for long-term follow up of those patients who received this specific implant. Early revision with polyethylene exchange is a successful treatment in patients when femoral and tibial components are well-positioned and well-fixed.

Pain Management for Periacetabular Osteotomy: A Systematic Review.

Background: Early post-operative pain control is essential to facilitate rapid recovery after orthopaedic surgery. Despite periacetabular osteotomy (PAO) being the gold standard treatment of prearthritic hip dysplasia, there is limited evidence assessing efficacy of early post-operative pain management strategies. Recent literature has focused on non-opioid supplemental treatments such as nerve blocks or local wound infiltration. The purpose of this systematic review was to assess efficacy of these interventions to reduce pain, facilitate mobilization, reduce length of stay after PAO surgery. Methods: A systematic review was created under the guidance of PRISMA from databases that included PubMed, OVID Medline, Embase, SCOPUS, Cochrane Central Register of Clinical Trials, and clinicaltrials.gov from their creation dates to 12/21/23. These studies were screen based on predetermined inclusion and exclusion criteria. Results: A total of six studies were included in this analysis from independent institutions. Three investigated nerve blocks (fascia iliaca, pericapsular, transversus abdominis), one investigated local wound infiltration with ropivacaine, one investigated high-dose dexamethasone, and the last investigated removal of the epidural catheter on postoperative (POD) 1 compared to POD 2. There were heterogeneous outcomes that were measured from these studies. In general, nerve blocks decreased opioid use, pain, and length of hospital stay. The local wound infiltration decreased pain on POD 3 and 4. Removing the epidural catheter on POD1 compared to POD 2 decreased pain and length of stay. High-dose dexamethasone use decreased opioid use on POD 1, otherwise, there was no difference in pain. Conclusion: In summary, supplemental pain management strategies peri-operatively for PAO surgery can decrease pain, opioid use, and length of hospital stay, though there are few studies assessing these interventions. Limiting opioid use after surgery reduces known negative consequences of the medication and facilitates rapid recovery. Clinical trials are needed that assess efficacy of supplemental pain management strategies after PAO surgery. Level of Evidence: II.

The Evolution of Hand Injuries at a State's Only Level I Trauma Center: A Look From the 1980s Through the Global Pandemic.

BACKGROUND: The purpose of this study is to evaluate any changes to hand trauma in the past three decades and through the COVID-19 pandemic. We hypothesized that improved consumer safety regulations, changes in access to care, and the impact of a global pandemic, among other variables, have significantly influenced the mechanisms and treatment of hand injuries between the 1980s, 2010s (pre-COVID-19), and 2020s (post-COVID-19). METHODS: A retrospective single-center review was performed at the only level I trauma center in Mississippi, identifying all hand trauma consultations between 2012-2019 and 2020-2021, compared to aggregated data from 1989. RESULTS: Car accidents, gunshots, saw injuries, door injuries, and falls increased in 2012-2019 and 2020-2021 compared to 1989, whereas knife injuries, glass injuries, industrial injuries, and burns decreased. Crush injuries, de-gloving injuries, and lacerations with irregular edges were increased in recent cohorts, corresponding with increased amputations and tissue loss. Skin and subcutaneous injuries decreased in modern cohorts, corresponding with a decreased ability for primary skin repair and the need for more flaps. Additionally, while hospitalizations have increased, patients have improved follow-up. CONCLUSIONS: The nature of hand trauma has changed significantly over the past three decades. Increased numbers of cars and greater access to firearms might have led to increased rates of high-energy trauma, whereas burn and industrial injuries have decreased, potentially secondary to improved safety efforts. Despite increased overall hand trauma, time to treatment and follow-up have improved. Through this study, we can be more cognizant of the evolution of hand trauma in the modern era. This can allow improved access to care and further refine management to optimize functionality for hand injuries.

Assessment of the comparative agreement between chest radiographs and CT scans in intensive care units.

PURPOSE: Chest radiographs in critically ill patients can be difficult to interpret due to technical and clinical factors. We sought to determine the agreement of chest radiographs and CT scans, and the inter-observer variation of chest radiograph interpretation, in intensive care units (ICUs). METHODS: Chest radiographs and corresponding thoracic computerised tomography (CT) scans (as reference standard) were collected from 45 ICU patients. All radiographs were analysed by 20 doctors (radiology consultants, radiology trainees, ICU consultants, ICU trainees) from 4 different centres, blinded to CT results. Specificity/sensitivity were determined for pleural effusion, lobar collapse and consolidation/atelectasis. Separately, Fleiss' kappa for multiple raters was used to determine inter-observer variation for chest radiographs. RESULTS: The median sensitivity and specificity of chest radiographs for detecting abnormalities seen on CTs scans were 43.2% and 85.9% respectively. Diagnostic sensitivity for pleural effusion was significantly higher among radiology consultants but no specialty/experience distinctions were observed for specificity. Median inter-observer kappa coefficient among assessors was 0.295 ("fair"). CONCLUSIONS: Chest radiographs commonly miss important radiological features in critically ill patients. Inter-observer agreement in chest radiograph interpretation is only "fair". Consultant radiologists are least likely to miss thoracic radiological abnormalities. The consequences of misdiagnosis by chest radiographs remain to be determined.

Aquacultured rainbow trout (Oncorhynchus mykiss) possess a large core intestinal microbiota that is resistant to variation in diet and rearing density.

As global aquaculture fish production continues to expand, an improved understanding of how environmental factors interact in fish health and production is needed. Significant advances have been made toward economical alternatives to costly fishmeal-based diets, such as grain-based formulations, and toward defining the effect of rearing density on fish health and production. Little research, however, has examined the effects of fishmeal- and grain-based diets in combination with alterations in rearing density. Moreover, it is unknown whether interactions between rearing density and diet impact the composition of the fish intestinal microbiota, which might in turn impact fish health and production. We fed aquacultured adult rainbow trout (Oncorhynchus mykiss) fishmeal- or grain-based diets, reared them under high- or low-density conditions for 10 months in a single aquaculture facility, and evaluated individual fish growth, production, fin indices, and intestinal microbiota composition using 16S rRNA gene sequencing. We found that the intestinal microbiotas were dominated by a shared core microbiota consisting of 52 bacterial lineages observed across all individuals, diets, and rearing densities. Variations in diet and rearing density resulted in only minor changes in intestinal microbiota composition despite significant effects of these variables on fish growth, performance, fillet quality, and welfare. Significant interactions between diet and rearing density were observed only in evaluations of fin indices and the relative abundance of the bacterial genus Staphylococcus. These results demonstrate that aquacultured rainbow trout can achieve remarkable consistency in intestinal microbiota composition and suggest the possibility of developing novel aquaculture strategies without overtly altering intestinal microbiota composition.

Fifteen-year survival analysis of an oxidised zirconium total knee arthroplasty.

BACKGROUND: Early studies have found Oxidised Zirconium (OxZr-Nb) total knee arthroplasties to have a low incidence of failure in young, high demand patients. Theoretically this is because they are low friction and hard wearing. However, there are a paucity of studies reporting on the outcome of these implants beyond ten years. The purpose of our study was to present an in-depth 15-year survival analysis of a cemented OxZr-Nb knee arthroplasty. METHODS: Data was collected prospectively and survival analysis undertaken with multiple strict end-points. Complication rates and patient reported outcomes were measured post-operatively. RESULTS: Six hundred and seventeen knee arthroplasties were analysed. Forty-nine patients required a reoperation for various reasons. Aseptic tibial loosening was the most common cause of failure (32.7%), occurring, on average, 2.8 years after the primary procedure. There was only one oxidised zirconium femoral failure recorded. Cumulative survivorship for reoperation for any reason was 91.52% at 15-years. On average, WOMAC (Western Ontario and McMaster University) score improved by 21.2 points at one-year post-surgery, which is beyond the considered minimum clinically important difference. CONCLUSION: This study presents a 15-year survival analysis of a cemented oxidised zirconium knee arthroplasty showing good survivorship over a range of analyses.