Thermal Conductivity of Single Wall Carbon Nanotubes: Diameter and Annealing Dependence

The thermal conductivity, k(T), of bulk single-wall carbon nanotubes (SWNT's) displays a linear temperature dependence at low T that has been attributed to 1D quantization of phonons. To explore this issue further, we have measured the k(T) of samples with varying average tube diameters. We observe linear k(T) up to higher temperatures in samples with smaller diameters, in agreement with a quantization picture. In addition, we have examined the effect of annealing on k(T). We observe an enhancement in k(T) for annealed samples which we attribute to healing of defects and removal of impurities. These measurements demonstrate how the thermal properties of an SWNT material can be controlled by manipulating its intrinsic nanoscale properties.Comment: Proc. of the XV. Int. Winterschool on Electronic Properties of Novel Materials, Kirchberg/Tirol, Austria, 200

Associations between primary healthcare and infant health outcomes: a cohort analysis of low-income mothers in Rio de Janeiro, Brazil

Background Expanding primary healthcare to urban poor populations is a priority in many low-and middle-income countries and is essential to achieve universal health coverage (UHC). Between 2008 and 2016 the city of Rio de Janeiro undertook an ambitious programme to rapidly expand primary care to low-income areas through the family health strategy (FHS). Infant health impacts of this roll out are unknown. This study examines associations between maternal FHS utilisation and birth outcomes, neonatal and infant mortality. Methods A cohort of 75,339 live births (January 2009–December 2014) to low-income mothers in Rio de Janeiro was linked to primary care, birth, hospital and death records. The relationship between maternal FHS use and infant health outcomes was assessed through logistic regression with inverse probability treatment weighting and regression adjustment. Socioeconomic inequalities in the associations between FHS use and outcomes were explored through interactions. Primary outcomes were neonatal and infant death. Thirteen secondary outcomes were also examined to explore other important health outcomes and potential mechanisms. Results A total of 9002 (12.0%) infants were born to mothers in the cohort who used FHS services either before pregnancy or in the first two trimesters. There was a total of 527 neonatal and 893 infant deaths. Maternal FHS usage during the first two trimesters was associated with substantial reductions in neonatal [adjusted odds ratio (aOR): 0.527, 95% confidence interval (95% CI): 0.345; 0.806] and infant mortality (aOR: 0.672, 95% CI: 0.48; 0.924). Infants born to lower-income mothers and those without formal employment had larger reductions in neonatal and infant mortality associated with FHS use. Maternal FHS in the first two trimesters use was also associated with more antenatal care consultations and a lower risk of low birth weight and preterm birth. Interpretation Expanding primary care to low-income populations in Rio de Janeiro was associated with improved infant health and health equity benefits. Funding DFID/MRC/Wellcome Trust/ESRC

Association of searching for health-related information online with self-rated health in the European Union.

BACKGROUND: The Internet is widely accessed for health information, but poor quality information may lead to health-worsening behaviours (e.g. non-compliance). Little is known about the health of individuals who use the Internet for health information. METHODS: Using the Flash Eurobarometer survey 404, European Union (EU) citizens aged ≥15 (n = 26 566) were asked about Internet utilisation for health information ('general' or 'disease-specific'), the sources used, self-rated health, and socioeconomic variables. Multivariable logistic regression was employed to assess the likelihood of bad self-rated health and accessing different health information sources (social networks, official website, online newspaper, dedicated websites, search engines). RESULTS: Those searching for general information were less likely to report bad health [odds ratios (OR) = 0.80; 95% confidence intervals (CI): 0.70-0.92], whilst those searching for disease-specific information were more likely (OR = 1.22; 95% CI: 1.07-1.38). Higher education and frequent doctor visits were associated with use of official websites and dedicated apps for health. Variation between EU member states in the proportion of people who had searched for general or disease-specific information online was high. CONCLUSIONS: Searching for general health information may be more conducive to better health, as it is easier to understand, and those accessing it may already be or looking to lead healthier lives. Disease-specific information may be harder to understand and assimilate into appropriate care worsening self-rated health. It may also be accessed if health services fail to meet individuals' needs, and health status is currently poor. Ensuring individuals' access to quality health services and health information will be key to addressing inequalities in health

Changes in support for bans of illicit drugs, tobacco, and alcohol among adolescents and young adults in Europe, 2008–2014

Objectives This study assessed the support for bans for tobacco, alcohol, and illicit drugs in adolescents and young adults across the European Union (EU). Methods Data were analysed for the years 2008, 2011, and 2014 for 27 EU member states. 37,253 individuals aged 15–24 years were interviewed ascertaining their support for banning tobacco, alcohol, cannabis, cocaine, heroin, and ecstasy. Changes over time were assessed using multilevel logistic regression. Results Support for banning heroin, ecstasy, and cocaine was constantly greater than 90%, although support fell over time. Support for cannabis ban declined (from 67.6% in 2008 to 53.7% in 2014) as well as support for alcohol ban (from 8.9% in 2008 to 6.9% in 2014) and tobacco ban (from 17.9% in 2008 to 16.5% in 2014). Conclusions Support for banning substances among EU adolescents and young adults varied, with high support for heroin, cocaine, and ecstasy, but less support for banning cannabis, tobacco, and alcohol. There was reduction in support of banning all substances between 2008 and 2014, but this varied substantially between European countries

Socioeconomic and racial/ethnic inequalities in depression prevalence and the treatment gap in Brazil: A decomposition analysis.

Depression is a major global health burden and there are stark socioeconomic inequalities in both the prevalence of depression and access to treatment for depression. In Brazil, racial/ethnic inequalities are of particular concern, but the factors contributing to these inequalities remain mostly unknown. This paper firstly explores determinants of depression and the treatment gap (i.e., untreated afflicted individuals) in Brazil and identifies if socio-economic and health system factors explain changes over time. Secondly, it analyses income and racial/ethnic inequalities in depression and the treatment gap and identifies factors explaining inequalities through decomposition methods. Data from two waves (2013 and 2019) of a representative household-based survey are used. In 2019, 10.8% of adults were depressed, but over 70% of depressed adults did not receive care. Black or brown/mixed Brazilians were more likely to have untreated depression, and region of residence was the most important determinant of these racial/ethnic inequalities. Notably, 44.6% of the difference in the treatment gap between white individuals and black and brown/mixed individuals was not explained by differences in observables, which could potentially be due to discrimination or difficulties in accessing treatment due to other non-observable characteristics. Employment, age, exposure to violence and physical activity are the main contributing factors to income inequalities in depression. These results suggest that policies aimed at improving the levels of exposure of lower-income individuals to risk factors may positively impact mental health and mental health inequalities, while addressing inequalities in service provision and resourcing for mental health and tackling barriers to access stemming from discrimination are essential to bridge the treatment gap equitably

Thermal transport measurements of individual multiwalled nanotubes

The thermal conductivity and thermoelectric power of a single carbon nanotube were measured using a microfabricated suspended device. The observed thermal conductivity is more than 3000 W/K m at room temperature, which is two orders of magnitude higher than the estimation from previous experiments that used macroscopic mat samples. The temperature dependence of the thermal conductivity of nanotubes exhibits a peak at 320 K due to the onset of Umklapp phonon scattering. The measured thermoelectric power shows linear temperature dependence with a value of 80 $\mu$V/K at room temperature.Comment: 4 pages, figures include