53 research outputs found

    Ionic and electronic structure of sodium clusters up to N=59

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    We determined the ionic and electronic structure of sodium clusters with even electron numbers and 2 to 59 atoms in axially averaged and three-dimensional density functional calculations. A local, phenomenological pseudopotential that reproduces important bulk and atomic properties and facilitates structure calculations has been developed. Photoabsorption spectra have been calculated for Na2\mathrm{Na}_2, Na8\mathrm{Na}_8, and Na9+\mathrm{Na}_9^+ to Na59+\mathrm{Na}_{59}^+. The consistent inclusion of ionic structure considerably improves agreement with experiment. An icosahedral growth pattern is observed for Na19+\mathrm{Na}_{19}^+ to Na59+\mathrm{Na}_{59}^+. This finding is supported by photoabsorption data.Comment: To appear in Phys. Rev. B 62. Version with figures in better quality can be requested from the author

    Zoledronate in the prevention of Paget's (ZiPP) : protocol for a randomised trial of genetic testing and targeted zoledronic acid therapy to prevent SQSTM1-mediated Paget's disease of bone.

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    Introduction Paget’s disease of bone (PDB) is characterised by increased and disorganised bone remodelling affecting one or more skeletal sites. Complications include bone pain, deformity, deafness and pathological fractures. Mutations in sequestosome-1 (SQSTM1) are strongly associated with the development of PDB. Bisphosphonate therapy can improve bone pain in PDB, but there is no evidence that treatment alters the natural history of PDB or prevents complications. The Zoledronate in the Prevention of Paget’s disease trial (ZiPP) will determine if prophylactic therapy with the bisphosphonate zoledronic acid (ZA) can delay or prevent the development of PDB in people who carry SQSTM1 mutations. Methods and analysis People with a family history of PDB aged >30 years who test positive for SQSTM1 mutations are eligible to take part. At the baseline visit, participants will be screened for the presence of bone lesions by radionuclide bone scan. Biochemical markers of bone turnover will be measured and questionnaires completed to assess pain, health-related quality of life (HRQoL), anxiety and depression. Participants will be randomised to receive a single intravenous infusion of 5 mg ZA or placebo and followed up annually for between 4 and 8 years at which point baseline assessments will be repeated. The primary endpoint will be new bone lesions assessed by radionuclide bone scan. Secondary endpoints will include changes in biochemical markers of bone turnover, pain, HRQoL, anxiety, depression and PDB-related skeletal events

    Prevalence estimates and risk factors for early childhood wheeze across europe: The europrevall birth cohort

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    Background Preschool wheeze is an important problem worldwide.No comparative population-based studies covering different countries have previously been undertaken.Objective T o assess the prevalence of early childhood wheeze across Europe and evaluate risk factors focusing on food allergy, breast feeding and smoke exposure.Methods I nfants from nine countries were recruited into the EuroPrevall birth cohort.At 12 and 24 months, data on wheeze, allergic signs/symptoms, feeding, smoke exposure, infections and day care attendance were collected using questionnaires.Poisson regression was used to assess risk factors for wheeze.Results 12 049 infants were recruited.Data from the second year of life were available in 8805 (73.1%).The prevalence of wheeze in the second year of life ranged from <2% in Lodz (Poland) and Vilnius (Lithuania) to 13.1% (95% CI 10.7% to 15.5%) in Southampton (UK) and 17.2% (95% CI 15.0% 19.5%) in Reykjavik (Iceland).In multivariable analysis, frequent lower respiratory tract infections in the first and second years of life (incidence rate ratio (IRR) 1.9 (95% CI 1.3 to 2.6) and 2.5 (95% CI 1.9 to3.4), respectively), postnatal maternal smoking (IRR 1.6, 95% CI 1.1 to 2.4), day care attendance (IRR 1.6, 95% CI 1.1 to 2.5) and male gender (IRR 1.3, 95% CI 1.0 to 1.7) were associated with wheeze.The strength of their association with wheeze differed between countries.Food allergy and breast feeding were not independently associated with wheeze.Conclusion T he prevalence of early childhood wheeze varied considerably across Europe.Lower respiratory tract infections, day care attendance, postnatal smoke exposure and male gender are important risk factors.Further research is needed to identify additional modifiable risk factors that may differ between countrie. © 2018 BMJ Publishing Group. All rights reserved

    Risk Factors for Hen's Egg Allergy in Europe: EuroPrevall Birth Cohort

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    Background: Hen's egg is one of the commonest causes of food allergy, but there are little data on its risk factors. Objective: To assess the risk factors, particularly eczema, for hen's egg allergy in the EuroPrevall birth cohort. Methods: In the pan-European EuroPrevall birth cohort, questionnaires were undertaken at 12 and 24 months or when parents reported symptoms. Children with suspected egg allergy were invited for skin prick testing, specific IgE assessment, and double-blind, placebo-controlled food challenge (DBPCFC) as indicated. Each egg allergy case (positive DBPCFC or egg-induced anaphylaxis) was allocated up to 2 age- and country-matched controls. Results: A total of 12,049 infants were recruited into the EuroPrevall birth cohort, and 9,336 (77.5%) were followed until 2 years. A total of 86 infants had egg allergy (84 by DBPCFC) and were matched with 140 controls. Independently associated with egg allergy were past/current eczema (adjusted odds ratio, 9.21; 95% CI, 2.65-32.04), Scoring Atopic Dermatitis (1.54 per 5 units; 1.28-1.86), antibiotics in the first week of life (6.17; 1.42-26.89), and current rhinitis (3.02; 1.04-8.78). Increasing eczema severity was associated with an increasing likelihood of egg allergy. Eczema was reported to have started 3.6 (SE, 0.5) months before egg allergy. Age of introduction of egg into the diet was not associated with egg allergy. Conclusions: Similar to peanut allergy, eczema was strongly associated with egg allergy development and the association increased with increasing eczema severity. The age of introduction of dietary egg was not a risk factor. The potential role of antibiotics in early life as a risk factor for egg allergy needs further examination. © 201
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