Silver nanowires as plasmonic compensators of luminescence quenching in single up-converting nanocrystals deposited on graphene.

Single nanocrystal spectroscopy is employed to demonstrate metal-enhanced optical response of Er3+/Yb3+ doped up-conversion nanocrystals deposited on graphene upon coupling with silver nanowires. Direct interaction between nanocrystals and graphene results in quenching of up-conversion emission and shortening of luminescence decay times, due to the energy transfer to graphene. The amount of the energy absorbed by graphene can be enhanced by coupling Er3+/Yb3+ doped up-conversion nanocrystals with silver nanowires. Microscopy studies with high spatial resolution together with time-resolved analysis of nanocrystal luminescence show increase of the emission rates with fourfold enhancement of the intensity for nanocrystals placed in the vicinity of silver nanowires. This strong enhancement emerges despite simultaneous interaction with graphene. The hybrid nanostructure provides thus a way to combine optical activity of up-conversion nanocrystals and enhancement provided by metallic nanowires with excellent electrical and mechanical properties of graphene.

A natural experiment on the impact of fruit supplementation on asthma symptoms in children.

A high fruit intake may reduce the risk of asthma. The English National School Fruit Scheme was introduced in the East Midlands region of the UK in June 2003 and in the Eastern region in September 2004. Questionnaires were distributed to children aged 4-6 yrs in schools in May 2003. This was repeated in May 2004 when those in the East Midlands had received free fruit for 1 yr and those in the Eastern region had not. Responses were obtained in 2004 for 4,971 (53%) and 5,770 (54%) children in the intervention and control regions, respectively. Despite an increase in fruit consumption in the intervention compared with the control region between 2003 and 2004, there was no difference between the two regions in the prevalence or severity of asthma symptoms after 1 yr of fruit supplementation (odds ratio for wheeze in the past 12 months in intervention compared with control region 1.00, 95% confidence interval 0.88-1.14). Providing free fruit at school for 1 yr does not have any immediate effect on prevalence or severity of asthma in young children, although these data do not refute the hypothesis that a higher increase in fruit intake improves measures of asthma control.

Does participation in a population-based dietary intervention scheme have a lasting impact on fruit intake in young children?

BACKGROUND: The National Schools Fruit Scheme (NSFS) is intended to improve fruit intake in young children by providing free daily fruit at school. METHODS: We used a parentally completed questionnaire for three consecutive years to study fruit intake in young children before, during and after participation in the NSFS compared with a control region. RESULTS: In 2003, 2004 and 2005, a total of 224, 220 and 179 schools, respectively, were studied with responses from 5,606, 5,111 and 3,382 children for each survey. Between 2003 and 2004, individual fruit consumption in the intervention region increased by more (from a median of 7.5 to 14.0 pieces/week) than in the control region (from a median of 9.2-11.0 pieces/week), resulting in a difference (P < 0.001) between the two regions in 2004. However, after ceasing to be eligible for the NSFS, fruit intake in children in the intervention region fell to a median of 12 pieces per week, lower than that in the control region (median value of 14 pieces per week, P = 0.02). CONCLUSIONS: School-based fruit distribution schemes providing free fruit at school appear to be an effective means of increasing dietary fruit intake in young children, including those who live in relatively socio-economically deprived areas. However, this approach does not influence fruit intake after the provision of free fruit ends, so schemes may need to be sustained to provide the maximum benefit to young children.

Secondhand smoke, dietary fruit intake, road traffic exposures, and the prevalence of asthma: a cross-sectional study in young children.

The authors have investigated the independent effects of exposure to secondhand smoke, road vehicle traffic, and dietary fruit intake in a cross-sectional study of asthma in young children. They surveyed all children aged 4-6 years in 235 schools in the East Midlands and East of England regions of the United Kingdom in 2003. Data on respiratory symptoms, diagnoses and treatment, smoking in the home, and dietary fruit intake were collected by parental questionnaire. A geographic information system was used to map postcodes and determine the distance of the home from the nearest main road. Responses were obtained from 11,562 children. Wheeze in the past year and physician-diagnosed asthma were reported by 14.1% and 18.2%, respectively. Both of these outcomes were more common in children who lived with a smoker, and the prevalence of asthma increased with the number of smokers in the home. Asthma prevalence was not associated with proximity of the home to a main road or with dietary fruit intake. The authors conclude that, of the potential risk factors considered in this study, preventing secondhand smoke exposure may be the most effective way of preventing asthma.

Oral magnesium and vitamin C supplements in asthma: a parallel group randomized placebo-controlled trial.

BACKGROUND: Epidemiological studies suggest that higher intakes of dietary vitamin C and magnesium may be associated with a reduced risk of asthma. OBJECTIVE: To determine whether vitamin C or magnesium supplements improve the clinical control of asthma in primary care patients. METHODS: A randomized, placebo-controlled, double-blind parallel group trial of 16 weeks supplementation with 1 g/day vitamin C, 450 mg/day magnesium chelate or matched placebo. Three hundred patients aged 18-60 years with physician-diagnosed asthma, controlled with at least one dose of an inhaled corticosteroid daily, were recruited from 24 primary care practices in Nottingham, UK. The main outcome measures were change in forced expiratory volume in 1 s, forced vital capacity, airway responsiveness to methacholine, mean morning and evening peak flow, symptom scores and bronchodilator use, both individually and as a combined summary statistic. RESULTS: There was no evidence of any beneficial effect of either supplement on any outcome measure of asthma control in the primary intention-to-treat analysis, or in an analysis restricted to participants who completed the study. CONCLUSIONS: Regular dietary supplementation with vitamin C or magnesium adds no clinical benefit to current standard therapy of asthma in primary care patients.

Effects of volatile organic compounds, damp, and other environmental exposures in the home on wheezing illness in children.

BACKGROUND: The effects of indoor exposure to volatile organic compounds (VOCs), including formaldehyde, on respiratory health are not clearly understood. The aim of this study was to determine the independent effects of VOCs and other common environmental exposures in the home on the risk and severity of persistent wheezing illness in children. METHODS: Total volatile organic compounds, formaldehyde, nitrogen dioxide, damp (on a four category scale of % wood moisture equivalent), and environmental tobacco smoke (from salivary cotinine) were measured objectively in the homes of 193 children with persistent wheezing illness and 223 controls aged 9-11 years in Nottingham, UK. RESULTS: The risk of wheezing illness was significantly increased only in relation to damp (odds ratio (OR) per increasing category=1.32 (95% confidence interval (CI), 1.00 to 1.75)), and was unrelated to the other exposures measured. Among cases, formaldehyde and damp were associated with more frequent nocturnal symptoms (OR per increasing quartile and category, respectively, 1.45 (1.06 to 1.98) and 1.97 (1.10 to 3.53)), significantly more so in atopic cases, but there was no effect of total volatile organic compounds, nitrogen dioxide, or cotinine. CONCLUSIONS: Domestic volatile organic compounds are not a major determinant of risk or severity of childhood wheezing illness, though formaldehyde may increase symptom severity. Indoor damp increases both the risk and severity of childhood wheezing illness.

Clinical trial comparing nicotine replacement therapy (NRT) plus brief counselling, brief counselling alone, and minimal intervention on smoking cessation in hospital inpatients.

BACKGROUND: Guidelines recommend that smoking cessation interventions are offered in all clinical settings to all smokers willing to make a quit attempt. Since the effectiveness of routine provision of behavioural counselling and nicotine replacement therapy (NRT) to smokers admitted to hospital has not been established, a randomised controlled trial of these interventions given together compared with counselling alone or minimal intervention was performed in hospital inpatients. METHODS: Medical and surgical inpatients who were current smokers at the time of admission were randomised to receive either usual care (no additional advice at admission), counselling alone (20 minute intervention with written materials), or NRT plus counselling (counselling intervention with a 6 week course of NRT). Continuous and point prevalence abstinence from smoking (validated by exhaled carbon monoxide <10 ppm) was measured at discharge from hospital and at 3 and 12 months, and self-reported reduction in cigarette consumption in smokers was assessed at 3 and 12 months. RESULTS: 274 inpatient smokers were enrolled. Abstinence was higher in the NRT plus counselling group (n=91) than in the counselling alone (n=91) or usual care (n=92) groups. The difference between the groups was significant for validated point prevalence abstinence at discharge (55%, 43%, 37% respectively, p=0.045) and at 12 months (17%, 6%, 8%, p=0.03). The respective differences in continuous validated abstinence at 12 months were 11%, 4%, 8% (p=0.25). There was no significant difference between counselling alone and usual care, or in reduction in cigarette consumption between the treatment groups. CONCLUSIONS: NRT given with brief counselling to hospital inpatients is an effective routine smoking cessation intervention.

Is smoking a communicable disease? Effect of exposure to ever smokers in school tutor groups on the risk of incident smoking in the first year of secondary school.

OBJECTIVE: To estimate the effect of joining a first year secondary school tutor group with a high prevalence of ever smoking on the risk of incident smoking in schoolchildren. DESIGN: Cross-sectional questionnaire survey. SETTING: 10 randomly selected secondary schools in Nottinghamshire, UK. PARTICIPANTS: Pupils in years (grades) 7-11 (aged 11-16 years). MAIN OUTCOME MEASURE: Incident smoking in the first year of secondary education, defined as pupils who reported smoking their first cigarette during year 7. RESULTS: Of 6522 pupils (75% of those eligible) who completed the questionnaire, 17% were current smokers and 49% had ever smoked, of whom 23% had started smoking in year 7. Incident smoking in year 7 was more common in girls, in children with parents or siblings who smoke, and in more deprived children, and was independently increased in relation to the proportion of ever smokers in the year 7 tutor group joined by the child (adjusted odds ratio of incident smoking for a child joining a year 7 tutor group in the highest relative to the lowest quartile of ever smoking prevalence 1.45, 95% confidence interval (CI) 1.11 to 1.89). Exposure to ever smokers in year 7 tutor groups also accounted for most of the increased risk of incident smoking associated with socioeconomic deprivation. CONCLUSIONS: The risk of incident smoking in children entering secondary education is independently increased by exposure to other ever smokers in school tutor groups. Incident smoking in adolescents is thus to some extent a communicable disorder, and may be partly preventable by policies that reduce exposure to smoking at school.

Risk of cryptogenic fibrosing alveolitis in metal workers.

We report increased proportional mortality from cryptogenic fibrosing alveolitis in the workforce of a major UK engineering company. Measures of metal exposure from unbiased historical occupational records showed that among employees who have worked with metal, the risk of death from or with cryptogenic fibrosing alveolitis increased in relation to the duration of metal-working.