Imaging biomarkers of lung ventilation in interstitial lung disease from ¹²⁹Xe and oxygen enhanced ¹H MRI

Purpose: To compare imaging biomarkers from hyperpolarised 129Xe ventilation MRI and dynamic oxygen-enhanced MRI (OE-MRI) with standard pulmonary function tests (PFT) in interstitial lung disease (ILD) patients. To evaluate if biomarkers can separate ILD subtypes and detect early signs of disease resolution or progression. Study type: Prospective longitudinal. Population: Forty-one ILD (fourteen idiopathic pulmonary fibrosis (IPF), eleven hypersensitivity pneumonitis (HP), eleven drug-induced ILD (DI-ILD), five connective tissue disease related-ILD (CTD-ILD)) patients and ten healthy volunteers imaged at visit 1. Thirty-four ILD patients completed visit 2 (eleven IPF, eight HP, ten DIILD, five CTD-ILD) after 6 or 26 weeks. Field strength/sequence: MRI was performed at 1.5 T, including inversion recovery T1 mapping, dynamic MRI acquisition with varying oxygen levels, and hyperpolarised 129Xe ventilation MRI. Subjects underwent standard spirometry and gas transfer testing. Assessment: Five 1H MRI and two 129Xe MRI ventilation metrics were compared with spirometry and gas transfer measurements. Statistical test: To evaluate differences at visit 1 among subgroups: ANOVA or Kruskal-Wallis rank tests with correction for multiple comparisons. To assess the relationships between imaging biomarkers, PFT, age and gender, at visit 1 and for the change between visit 1 and 2: Pearson correlations and multilinear regression models. Results: The global PFT tests could not distinguish ILD subtypes. Percentage ventilated volumes were lower in ILD patients than in HVs when measured with 129Xe MRI (HV 97.4 ± 2.6, CTD-ILD: 91.0 ± 4.8 p = 0.017, DI-ILD 90.1 ± 7.4 p = 0.003, HP 92.6 ± 4.0 p = 0.013, IPF 88.1 ± 6.5 p < 0.001), but not with OE-MRI. 129Xe reported more heterogeneous ventilation in DI-ILD and IPF than in HV, and OE-MRI reported more heterogeneous ventilation in DI-ILD and IPF than in HP or CTD-ILD. The longitudinal changes reported by the imaging biomarkers did not correlate with the PFT changes between visits. Data conclusion: Neither 129Xe ventilation nor OE-MRI biomarkers investigated in this study were able to differentiate between ILD subtypes, suggesting that ventilation-only biomarkers are not indicated for this task. Limited but progressive loss of ventilated volume as measured by 129Xe-MRI may be present as the biomarker of focal disease progresses. OE-MRI biomarkers are feasible in ILD patients and do not correlate strongly with PFT. Both OE-MRI and 129Xe MRI revealed more spatially heterogeneous ventilation in DI-ILD and IPF

Simulations of neutron background in a time projection chamber relevant to dark matter searches

Presented here are results of simulations of neutron background performed for a time projection chamber acting as a particle dark matter detector in an underground laboratory. The investigated background includes neutrons from rock and detector components, generated via spontaneous fission and (alpha, n) reactions, as well as those due to cosmic-ray muons. Neutrons were propagated to the sensitive volume of the detector and the nuclear recoil spectra were calculated. Methods of neutron background suppression were also examined and limitations to the sensitivity of a gaseous dark matter detector are discussed. Results indicate that neutrons should not limit sensitivity to WIMP-nucleon interactions down to a level of (1 - 3) x 10^{-8} pb in a 10 kg detector.Comment: 27 pages (total, including 3 tables and 11 figures). Accepted for publication in Nuclear Instruments and Methods in Physics Research - Section

Isotopic analysis of faunal material from South Uist, Western Isles, Scotland

This paper reports on the results from stable isotope analysis of faunal bone collagen from a number of Iron Age and later sites on the island of South Uist, in the Western Isles, Scotland. This preliminary investigation into the isotopic signatures of the fauna is part of a larger project to model the interaction between humans, animals, and the broader environment in the Western Isles. The results demonstrate that the island fauna data fall within the range of expected results for the UK, with the terrestrial herbivorous diets of cattle and sheep confi rmed. The isotopic composition for pigs suggests that some of these animals had an omnivorous diet, whilst a single red deer value might be suggestive of the consumption of marine foods, such as by grazing on seaweed. However, further analysis is needed in order to verify this anomalous isotopic ratio

Solar-Sail Transfers from Invariant Objects to L5 Periodic Orbits

This paper presents the design of solar-sail transfer trajectories to solar-sail displaced libration point orbits in the Earth- Moon system. The existence of families of solar-sail displaced libration point orbits in the Earth-Moon system has recently been demonstrated. These families originate from complementing the dynamics of the classical Earth-Moon circular restricted three-body problem with a solar-sail induced acceleration. Previous work has furthermore demonstrated the applicability of these orbits for high-latitude observation of the Earth and Moon. To not only demonstrate the existence and applicability of these orbits, but also their accessibility, this paper investigates the design of solar-sail transfers from Earth-bound parking orbits to a subset of these orbits. Initial guesses for the transfers are generated using reverse time propagation of the dynamics, where the control is provided by a locally optimal steering law. These initial guesses are subsequently used to initialize a 12th-order Gauss-Lobatto collocation method to satisfy a large number of constraints: departure from specific high Earth orbits, a minimum altitude with respect to the Earth and the Moon, and a maximum rotation rate of the solar sail. As an application of the developed methodology, this paper shows results for transferring two spacecraft to a constellation of displaced vertical Lyapunov orbits at the Earth-Moon L2 point. This constellation has been shown to provide continuous coverage of the lunar Aitken Basin and the lunar South Pole while maintaining a continuous line of sight with Earth. Sets of feasible trajectories for both spacecraft with identical launch conditions are produced in order for the constellation to be initiated using a single Soyuz launch. Such a Soyuz launch can deliver two 1160-kg spacecraft into the found transfer trajectories. One of the spacecraft subsequently requires a transfer time of 53.06 days to enter its constellation orbit, while the transfer of the other spacecraft takes 67.89 days. These results prove the accessibility of solar-sail displaced libration point orbits in the Earth-Moon system, thereby reaffirming the potential of solar-sail technology to enable novel scientific missions in the Earth-Moon system

Sedimentary records of sewage pollution using faecal markers in contrasting peri-urban shallow lakes

Sewage contamination in shallow lake sediments is of concern because the pathogens, organic matter and nutrients contribute to the deterioration of the water-bodies' health and ecology. Sediment cores from three shallow lakes (Coneries, Church and Clifton Ponds) within Attenborough nature reserve located downstream of sewage treatment works were analysed for TOC, C/N, δ13C, δ15N, bacterial coliforms and faecal sterols. 210Pb and 137Cs activities were used to date the sediments. Elemental analysis suggests that the source of organic matter was algal and down profile changes in δ13C indicate a possible decrease in productivity with time which could be due to improvements in sewage treatment. δ15N for Coneries Pond are slightly higher than those observed in Church or Clifton and are consistent with a sewage-derived nitrate source which has been diluted by non-sewage sources of N. The similarity in δ15N values (+ 12‰ to + 10‰) indicates that the three ponds were not entirely hydrologically isolated. Analysis by gas chromatography/mass spectrometry (GC/MS) reveals that Coneries Pond had sterol concentrations in the range 20 to 30 μg/g (dry wt.), whereas, those from Clifton and Church Ponds were lower. The highest concentrations of the human-sourced sewage marker 5β-coprostanol were observed in the top 40 cm of Coneries Pond with values up to 2.2 μg/g. In contrast, Church and Clifton Pond sediments contain only trace amounts throughout. Down-profile comparison of 5β-coprostanol/cholesterol, 5β-coprostanol/(5β-coprostanol + 5α-cholestanol) and 5β-epicoprostanol/coprostanol as well as 5α-cholestanol/cholesterol suggests that Coneries Pond has received appreciable amounts of faecal contamination. Examination of 5β-stigmastanol (marker for herbivorous/ruminant animals) down core concentrations suggests a recent decrease in manure slurry input to Coneries Pond. The greater concentration of β-sitosterol in sediments from Church and Clifton Ponds as compared to Coneries is attributed in part to their greater diversity and extent of aquatic plants and avian faeces

Microsurgical reconstructions for head and neck cancers in elderly aged >80 years: An analysis of surgical outcomes and quality of life

Background: The rising incidence of primary head and neck (H&N) cancers in the elderly presents a dilemma regarding the appropriateness of complex surgery in this assumed frail age group. With limited data on surgical morbidity, survival, and patient quality of life (QOL), this analysis aimed to broaden the understanding of safety and effectiveness of microsurgical treatment in very elderly H&N cancer patients.  Methods: A prospective database analysis was used to evaluate surgical outcomes (morbidity, survival, and QOL) in all patients aged 80 years and older undergoing microsurgical reconstruction for cutaneous and intra-oral H&N cancers between 2004 and 2014. Outcomes were assessed for their association with surgical, tumour, and patient variables. Comorbidities were categorized by the ACE27 index and postoperative morbidity by the Clavien–Dindo scoring system. QOL was analyzed using the UW-QOLv4.  Results: Of 720 microsurgical reconstructions, 96 patients were identified. Median survival was 25 months. The ACE27 index was the only variable significantly associated with survival with a 5-year survival of 59.2 % in the least comorbid group versus 19.7 % in the most comorbid group (p 0.015). ACE-27 showed influence on socioemotional QoL scores. Physical QOL scores were influenced by tumour and operative factors. Patients were found to value physical QOL over socioemotional.  Conclusions: Microsurgical reconstructions are well tolerated in the very elderly patients and should be considered predominantly based on comorbidity. Tumour stage, flap type, and cancer site should still form part of the preoperative counseling due to their implication on postoperative physical function

A closed-shaft garderobe and associated medieval structures at Jennings Yard, Windsor, Berkshire

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