Publications by authors named "David Mckenzie"

Within a resource-limited healthcare system, an emphasis on financial accountability is imperative. Over the past decade at our institution, there have been many operational changes employed to improve patient care during oncologic head and neck resections with free flap (HNFF) reconstruction. The objective of this study is to assess whether these changes are associated with cost savings.

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  • Researchers demonstrate that quantum interference can improve coherent electron transmission in perovskite tandem solar cells by using ultrathin layers of indium tin oxide (ITO).
  • They create a model utilizing a finite difference time domain approach to solve the time-dependent Schrödinger equation, incorporating an imaginary component to account for losses from incoherent scattering.
  • Their findings align with observed efficiency trends based on ITO thickness, indicating a possible optimized design for better solar cell performance.
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  • Metabolic dysfunction-associated steatotic liver disease (MASLD) is common in obese individuals, and this study examines how body mass index (BMI) affects health outcomes in these patients.
  • A cohort of 32,900 MASLD patients, tracked over an average of 5.5 years, was categorized into six BMI groups to assess risks associated with liver issues and cancer.
  • Findings revealed a J-shaped relationship between BMI and health risks, indicating that patients with very low (<25 kg/m²) or high (≥50 kg/m²) BMI had significantly higher risks for liver decompensation, obesity-related cancers, and all-cause mortality compared to those with a BMI of 25-<30 kg/m².
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Water temperature governs physiological functions such as growth, energy allocation, and sex determination in ectothermic species. The European sea bass (Dicentrarchus labrax) is a major species in European aquaculture, exhibiting early dimorphic growth favoring females. The species has a polygenic sex determination system that interacts with water temperature to determine an individual's sex, with two periods during development that are sensitive to temperature.

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Pioneering road markings for motorcyclists, designed as Perceptual Rider Information for Maximising Expertise and Enjoyment (PRIMEs) were installed on approach to demanding bends at 22 trial sites and two comparison sites across the West Highlands of Scotland. The markings provided a series of 'gateways' to encourage safer riding. With 32,213 motorcyclists observed, the following statistically significant results were observed: speed reductions at 10 trial sites; positive changes in lateral position at the final PRIME gateway marking at 15 trial sites and positive changes in lateral position at the apex of the bend at 13 trial sites; reductions in braking at nine trial sites; increases use of PRIME road markings across 18 of the 22 trial sites.

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The present work describes a preclinical trial (, and ) protocol to assess the biomechanical performance and osteogenic capability of 3D-printed polymeric scaffolds implants used to repair partial defects in a sheep mandible. The protocol spans multiple steps of the medical device development pipeline, including initial concept design of the scaffold implant, digital twin finite element modeling, manufacturing of the device prototype, device implantation, and laboratory mechanical testing. First, a patient-specific one-body scaffold implant used for reconstructing a critical-sized defect along the lower border of the sheep mandible ramus was designed using on computed-tomographic (CT) imagery and computer-aided design software.

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Even with the best infection control protocols in place, the risk of a hospital-acquired infection of the surface of an implanted device remains significant. A bacterial biofilm can form and has the potential to escape the host immune system and develop resistance to conventional antibiotics, ultimately causing the implant to fail, seriously impacting patient well-being. Here, we demonstrate a 4 log reduction in the infection rate by the common pathogen of 3D-printed polyaryl ether ketone (PAEK) polymeric surfaces by covalently binding the antimicrobial peptide Mel4 to the surface using plasma immersion ion implantation (PIII) treatment.

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The use of physical plasma to treat cancer is an emerging field, and interest in its applications in oncology is increasing rapidly. Physical plasma can be used directly by aiming the plasma jet onto cells or tissue, or indirectly, where a plasma-treated solution is applied. A key scientific question is the mechanism by which physical plasma achieves selective killing of cancer over normal cells.

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Considerable research is being undertaken to develop novel biomaterials-based approaches for surgical reconstruction of bone defects. This extends to three-dimensional (3D) printed materials that provide stable, structural, and functional support . However, few preclinical models can simulate human biological conditions for clinically relevant testing.

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Head and neck cancer (HNC) treatment often consists of major surgery followed by adjuvant therapy, which can result in treatment-related side effects, decreased physical function, and diminished quality of life. Perioperative nutrition interventions and early mobilization improve recovery after HNC treatment. However, there are few studies on prehabilitation that include exercise within the HNC surgical care pathway.

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Diamond's unique properties on the nanoscale make it one of the most important materials for use in biosensors and quantum computing and for components that can withstand the harsh environments of space. We synthesize oriented, faceted diamond particles by flash laser heating of glassy carbon at 16 GPa and 2300 K. Detailed transmission electron microscopy shows them to consist of a mosaic of diamond nanocrystals frequently joined at twin boundaries forming microtwins.

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Autologous bone replacement remains the preferred treatment for segmental defects of the mandible; however, it cannot replicate complex facial geometry and causes donor site morbidity. Bone tissue engineering has the potential to overcome these limitations. Various commercially available calcium phosphate-based bone substitutes (Novabone, BioOss, and Zengro) are commonly used in dentistry for small bone defects around teeth and implants.

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Polydimethyl glutarimide (PMGI) layers with sub-micron thicknesses have been modified in a 2.5 kV Ar plasma immersion ion implantation (PIII) process to introduce free radical covalent binding sites. The surface roughness of the PMGI increased after the PIII treatment but no through-layer defects were observed.

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A decline in size is increasingly recognised as a major response by ectothermic species to global warming. Mechanisms underlying this phenomenon are poorly understood but could include changes in energy balance of consumers, driven by declines in prey size coupled with increased energy demands due to warming. The sardine Sardina pilchardus is a prime example of animal shrinking, European populations of this planktivorous fish are undergoing profound decreases in body condition and adult size.

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The uncertainty of climate change is a significant challenge prompting Australian farmers to create different thinking and different management systems that ensure sustained farm business viability and continuity, particularly in extreme environments. The purpose of this study was to explore the conditions and adaptive processes for managing farm resilience and cyclic adaptation pathways, in response to climate change. A positive deviance sample of farmers was interviewed, and data was collected from a cohort of twenty-two climate change innovators across Eastern Australia.

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Background: Antibody mediated rejection (ABMR) of kidney transplants has been shown to occur in the absence of a known donor specific antibody to human leucocyte antigen (HLA). Antibodies to the human neutrophil antigen (HNA) system have been detected in kidney transplant recipients and linked to ABMR in the absence of an HLA donor specific antibody (DSA), but there remains limited literature regarding this.

Methods: Case series analysis was carried out examining three cases of HNA-3a antibody positive flow cytometry cross match (FC-XM) from two transplant centres in Scotland.

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Orthopedic-device-related infections are notorious for causing physical and psychological trauma to patients suffering from them. Traditional methods of treating these infections have relied heavily on antibiotics and are becoming ineffectual due to the rise of antibiotic-resistant bacteria. Mimics of antimicrobial peptides have emerged as exciting alternatives due to their favorable antibacterial properties and lack of propensity for generating resistant bacteria.

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Importance: Head and neck oncological resection and reconstruction is a complex process that requires multidisciplinary collaboration and prolonged operative time. Numerous factors are associated with operative time, including a surgeon's experience, team familiarity, and the use of new technologies. It is paramount to evaluate the contribution of these factors and modalities on operative time to facilitate broad adoption of the most effective modalities and reduce complications associated with prolonged operative time.

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Many school systems across the globe turned to online education during the COVID-19 pandemic. This context differs significantly from the prepandemic situation in which massive open online courses attracted large numbers of voluntary learners who struggled with completion. Students who are provided online courses by their high schools also have their behavior determined by actions of their teachers and school system.

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Eight juvenile European seabass were exposed to two thermal ramping protocols with different levels of aerobic activity and tolerance endpoint: the critical thermal maximum for swimming (CTSmax) while exercising aerobically until fatigue and the critical thermal maximum (CTmax) under static conditions until loss of equilibrium (LOE). In the CTSmax protocol, warming caused a profound increase in the rate of oxygen uptake (ṀO2), culminating in a gait transition from steady aerobic towards unsteady anaerobic swimming, then fatigue at 30.3±0.

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  • Researchers studied a type of pancreatic tumor called sclerosing variant of pancreatic neuroendocrine tumor (spNET), which has less cells and more fibrous tissue compared to a typical type (tpNET).
  • Out of 25 spNET samples, only 13 were good for diagnosis, making it hard to identify, especially since they are often already spreading when found.
  • Early diagnosis is really important because these small tumors can spread to nearby lymph nodes and the liver, making them more dangerous.
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Critical thermal maxima methodology (CTM) has been used to infer acute upper thermal tolerance in fishes since the 1950s, yet its ecological relevance remains debated. In this study, the authors synthesize evidence to identify methodological concerns and common misconceptions that have limited the interpretation of critical thermal maximum (CT ; value for an individual fish during one trial) in ecological and evolutionary studies of fishes. They identified limitations of, and opportunities for, using CT as a metric in experiments, focusing on rates of thermal ramping, acclimation regimes, thermal safety margins, methodological endpoints, links to performance traits and repeatability.

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Aquatic ecosystems can exhibit seasonal variation in resource availability and animals have evolved to cope with the associated caloric restriction. During winter in the NW Mediterranean Sea, the European sardine Sardina pilchardus naturally experiences caloric restriction owing to a decrease in the diversity and quantity of plankton. However, ongoing global warming has had deleterious effects on plankton communities such that food shortages may occur throughout the year, especially under warm conditions in the summer.

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