Publications by authors named "Hart N"

Background: Skeletal muscle wasting and weakness are significant complications of critical illness, associated with degree of illness severity and periods of reduced mobility during mechanical ventilation. They contribute to the profound physical and functional deficits observed in survivors. These impairments may persist for many years following discharge from the intensive care unit (ICU) and can markedly influence health-related quality of life.

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Objectives: The International Cancer Benchmarking Partnership (ICBP) is a collaboration between 6 countries and 12 jurisdictions with similar primary care-led health services. This study investigates primary care physician (PCP) behaviour and systems that may contribute to the timeliness of investigating for cancer and subsequently, international survival differences.

Design: A validated survey administered to PCPs via the internet set out in two parts: direct questions on primary care structure and practice relating to cancer diagnosis, and clinical vignettes, assessing management of scenarios relating to the diagnosis of lung, colorectal or ovarian cancer.

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The dominant hypothesis for the evolutionary origin of snakes from 'lizards' (non-snake squamates) is that stem snakes acquired many snake features while passing through a profound burrowing (fossorial) phase. To investigate this, we examined the visual pigments and their encoding opsin genes in a range of squamate reptiles, focusing on fossorial lizards and snakes. We sequenced opsin transcripts isolated from retinal cDNA and used microspectrophotometry to measure directly the spectral absorbance of the photoreceptor visual pigments in a subset of samples.

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The world in color presents a dazzling dimension of phenotypic variation. Biological interest in this variation has burgeoned, due to both increased means for quantifying spectral information and heightened appreciation for how animals view the world differently than humans. Effective study of color traits is challenged by how to best quantify visual perception in nonhuman species.

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We experimentally studied the dependence of high harmonic generation in argon and molecular hydrogen on pressure changes in a gas jet that cause variations of the phase matching conditions and absorption. The study was performed at a peak laser intensity of ∼1.5 × 10(14) W/cm(2).

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Introduction: Obesity is an escalating issue, with an accompanying increase in referrals of patients with obesity-related respiratory failure. Currently, these patients are electively admitted to hospital for initiation of non-invasive ventilation (NIV), but it is unknown whether outpatient initiation is as effective as inpatient set-up. We hypothesise that outpatient set-up using an autotitrating NIV device will be more cost-effective than a nurse-led inpatient titration and set-up.

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Introduction: Acute skeletal muscle wasting is a major contributor to post critical illness physical impairment. However, the bone response remains uncharacterized. We prospectively investigated the early changes in bone mineral density (BMD) and fracture risk in critical illness.

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Objectives: A rapid and early loss of skeletal muscle mass underlies the physical disability common amongst survivors of critical illness. However, skeletal muscle function depends not only on its quantity but its quality, which may be adversely affected. We set out to characterise the changes in macroscopic muscle echogenicity and fascial characteristics that occur early in critical illness, and to relate these to microscopic histologically defined myofibre necrosis and fascial pathology.

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Red/near-infrared light therapy (R/NIR-LT), delivered by laser or light emitting diode (LED), improves functional and morphological outcomes in a range of central nervous system injuries in vivo, possibly by reducing oxidative stress. However, effects of R/NIR-LT on oxidative stress have been shown to vary depending on wavelength or intensity of irradiation. Studies comparing treatment parameters are lacking, due to absence of commercially available devices that deliver multiple wavelengths or intensities, suitable for high through-put in vitro optimization studies.

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Deep-sea fishes possess several adaptations to facilitate vision where light detection is pushed to its limit. Lanternfishes (Myctophidae), one of the world's most abundant groups of mesopelagic fishes, possess a novel and unique visual specialisation, a sexually dimorphic photostable yellow pigmentation, constituting the first record of a visual sexual dimorphism in any non-primate vertebrate. The topographic distribution of the yellow pigmentation across the retina is species specific, varying in location, shape and size.

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Change of direction (COD) and agility require the integration of multiple components to produce a faster performance. However, the mechanisms contributing to a faster performance without the confounding factor of athlete expertise or gender is currently unknown. Therefore, the purpose of this study was to assess body composition, strength, and kinetic profile required for a faster COD and agility performance across multiple directional changes.

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Purpose: The aim of this study was to investigate feasibility of exercise-based rehabilitation delivered after hospital discharge in patients with intensive care unit-acquired weakness (ICU-AW).

Materials And Methods: Twenty adult patients, mechanically ventilated for more than 48 hours, with ICU-AW diagnosis at ICU discharge were included in a pilot feasibility randomized controlled trial receiving a 16-session exercise-based rehabilitation program. Twenty-one patients without ICU-AW participated in a nested observational cohort study.

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Article Synopsis
  • The study aims to assess the effectiveness of using ultrasound to measure skeletal muscle architecture in critically ill adults, particularly in ICU settings.
  • Researchers searched through seven electronic databases and personal libraries to find relevant quantitative studies published in English, focusing on those that met specific criteria.
  • The findings show that ultrasound is reliable for tracking muscle changes in critically ill patients but tends to underestimate results compared to more invasive methods like muscle biopsy.
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Single-gene and whole-genome duplications are important evolutionary mechanisms that contribute to biological diversification by launching new genetic raw material. For example, the evolution of animal vision is tightly linked to the expansion of the opsin gene family encoding light-absorbing visual pigments. In teleost fishes, the most species-rich vertebrate group, opsins are particularly diverse and key to the successful colonization of habitats ranging from the bioluminescence-biased but basically dark deep sea to clear mountain streams.

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Rationale: Profound muscle weakness during and after critical illness is termed intensive care unit-acquired weakness (ICUAW).

Objectives: To develop diagnostic recommendations for ICUAW.

Methods: A multidisciplinary expert committee generated diagnostic questions.

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Background: Timely initiation of weaning from mechanical ventilation (MV) is important. Non-validated screening criteria may delay weaning if too prescriptive. This study observed physician-led utilisation of pressure support ventilation (PSV), referenced to four reported conventional screening criteria hypothesising that these criteria would have delayed the weaning progress.

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Background: Chronic respiratory failure complicating sleep-disordered breathing in obese patients has important adverse clinical implications in terms of morbidity, mortality and healthcare utilisation. Screening strategies are essential to identify obese patients with chronic respiratory failure.

Method: Prospective data were collected from patients with obesity-related sleep-disordered breathing admitted for respiratory assessment at a UK national sleep and ventilation centre.

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The avian retina possesses one of the most diverse complements of photoreceptor types among vertebrates but little is known about their spatial distribution. Here we used retinal wholemounts and stereological methods to present the first complete maps of the topographic distribution of rods and cones in four species of Australian passerines with diverse trophic specializations. All species studied have one central and one temporal rod-free zone.

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Red/near-infrared irradiation therapy (R/NIR-IT) delivered by laser or light-emitting diode (LED) has improved functional outcomes in a range of CNS injuries. However, translation of R/NIR-IT to the clinic for treatment of neurotrauma has been hampered by lack of comparative information regarding the degree of penetration of the delivered irradiation to the injury site and the optimal treatment parameters for different CNS injuries. We compared the treatment efficacy of R/NIR-IT at 670 nm and 830 nm, provided by narrow-band LED arrays adjusted to produce equal irradiance, in four in vivo rat models of CNS injury: partial optic nerve transection, light-induced retinal degeneration, traumatic brain injury (TBI) and spinal cord injury (SCI).

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The mesopelagic zone is a visual scene continuum in which organisms have developed various strategies to optimize photon capture. Here, we used light microscopy, stereology-assisted retinal topographic mapping, spectrophotometry and microspectrophotometry to investigate the visual ecology of deep-sea bioluminescent sharks [four etmopterid species (Etmopterus lucifer, E. splendidus, E.

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Bats comprise 20% of all mammalian species and display a number of characteristics, including true flight, echolocation, and a heightened ability to resist viral load that uniquely position this group for comparative genomic studies. Here we searched for evidence of genomic variation consistent with sensory rewiring through bat evolution. We focused on two species with divergent sensory preferences.

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Background: Obesity hypoventilation syndrome (OHS) conventionally includes awake hypercapnia, but an isolated raised bicarbonate, even in the absence of awake hypercapnia, may represent evidence of "early" OHS. We investigated whether such individuals exhibit certain features characteristic of established OHS.

Methods: Obese subjects (BMI > 30 kg/m(2)) were identified from a variety of sources and divided into those with (1) normal blood gas measurements and normal acid-base balance, (2) an isolated raised base excess (BE) (≥ 2 mmol/L), and (3) awake hypercapnia (> 6 kPa; ie, established OHS).

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A gap in the medical undergraduate curriculum on safe moving and handling of patients was identified, and a project to enhance moving and handling education for undergraduates in various healthcare disciplines was undertaken. A team of nurses, doctors, physiotherapists and e-learning professionals developed a cross-discipline e-learning resource, piloted with medical and nursing students at Queen's University Belfast. One outcome of the project was the development of a deeper recognition of the common curriculum across healthcare disciplines.

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