Novel sol–gel preparation of (PO)–(CaO)–(NaO)–(TiO) bioresorbable glasses (X = 0.05, 0.1, and 0.15)

Quaternary phosphate-based glasses in the PO–CaO–NaO–TiO system with a fixed PO and CaO content of 40 and 25 mol% respectively have been successfully synthesised via sol–gel method and bulk, transparent samples were obtained. The structure, elemental proportion, and thermal properties of stabilised sol–gel glasses have been characterised using X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), P nuclear magnetic resonance (P NMR), titanium K-edge X-ray absorption near-edge structure (XANES), fourier transform infrared (FTIR) spectroscopy, and differential thermal analysis (DTA). The XRD results confirmed the amorphous nature for all stabilized sol–gel derived glasses. The EDX result shows the relatively low loss of phosphorus during the sol–gel process and Ti K-edge XANES confirmed titanium in the glass structure is in mainly six-fold coordination environment. The P NMR and FTIR results revealed that the glass structure consist of mainly Q and Q phosphate units and the Ti cation was acting as a cross-linking between phosphate units. In addition DTA results confirmed a decrease in the glass transition and crystallisation temperature with increasing NaO content. Ion release studies also demonstrated a decrease in degradation rates with increasing TiO content therefore supporting the use of these glasses for biomedical applications that require a degree of control over glass degradation. These sol–gel glasses also offer the potential to incorporate proactive molecules for drug delivery application due to the low synthesis temperature employed

Global health governance : framework convention on tobacco control (FCTC), the Doha Declaration, and democratisation

Global public health agreements are heralded as a success for the affirmation of the right to health within a complex and contested political landscape. However, the practical implementation of such agreements at the national level is often overlooked. This article outlines two radically different global health agreements: The Doha Declaration on the Trade-Related Aspects of Intellectual Property Rights (TRIPS) agreement and Public Health; and the Framework Convention on Tobacco Control (FCTC). We identify significant challenges in their implementation, particularly for low and middle income countries. Shifts in the policy network constellations around these two agreements have allowed for some positive influence by civil society. Yet industry influence at the national level constrains effective implementation and those affected by these policies have largely been left on the periphery. The broader provisions of these two agreements have been watered down by vested interests and donor conditions. We advocate for both activist and academic actors to play a significant role in highlighting the consequences of these power asymmetries. Deliberative democracy may be the key to addressing these challenges in a way that empowers those presently excluded from effective participation in the policy process.<br /

Exploring the implementation of the framework convention on tobacco control in four small island developing states of the Pacific: a qualitative study

OBJECTIVES: To determine what variables influence the implementation of the Framework Convention on Tobacco Control (FCTC) in small island developing states of the Pacific and how they affect its success or failure. To explore how barriers can be overcome and opportunities utilised to ensure an effective FCTC implementation in the Pacific Islands. DESIGN: A mixed methods, multiple case study consisting of primarily qualitative data in the form of semistructured interviews, document analysis and opportunistic observation. SETTING: Field visits were undertaken to collect data in the Cook Islands, Vanuatu, Palau and Nauru. The key informants were interviewed in the major cities or islands of each respective country: Rarotonga, Port Vila, Koror and Nauru. PARTICIPANTS: Purposive sampling was used to select 39 informants, whose roles were associated with FCTC implementation. Most of the participants worked in health-oriented positions in the government and non-government organisations. RESULTS: Each country made a significant progress towards FCTC implementation. Overall, strong policy content, public support and limited pro-tobacco coalition activity were conducive to FCTC implementation, but the challenges were evident in the form of limited capacity, limited antitobacco coalition activity and limited political commitment outside the ministries of health in each country. CONCLUSIONS: Further efforts are needed for full FCTC implementation, through building capacity and using resources effectively, growing commitment to FCTC beyond the health sector, fostering growth in antitobacco coalition activity, exploiting the limited pro-tobacco activity that may be present and garnering public support for tobacco control. These lessons may be particularly important for other small island developing states in the Pacific and developing countries elsewhere

What four decades of earth observation tell us about land degradation in the Sahel?

The assessment of land degradation and the quantification of its effects on land productivity have been both a scientific and political challenge. After four decades of Earth Observation (EO) applications, little agreement has been gained on the magnitude and direction of land degradation in the Sahel. The large number of EO datasets and methods associated with the complex interactions among biophysical and social drivers of ecosystem changes make it difficult to apply aggregated EO indices for these non-linear processes. Hence, while many studies stress that the Sahel is greening, others indicate no trend or browning. The different generations of sensors, the granularity of studies, the study period, the applied indices and the assumptions and/or computational methods impact these trends. Consequently, many uncertainties exist in regression models between rainfall, biomass and various indices that limit the ability of EO science to adequately assess and develop a consistent message on the magnitude of land degradation. We suggest several improvements: (1) harmonize time-series data, (2) promote knowledge networks, (3) improve data-access, (4) fill data gaps, (5) agree on scales and assumptions, (6) set up a denser network of long-term field-surveys and (7) consider local perceptions and social dynamics. To allow multiple perspectives and avoid erroneous interpretations, we underline that EO results should not be interpreted without contextual knowledge

Polypropylene pipe interface strength on marine sandy soils with varying coarse fraction

The interface shear strength of polypropylene pipeline coatings and marine sandy soils was investigated through direct and surface-over-soil interface shear box testing. Polypropylene specimens were acquired by removal from existing manufactured steel pipes and test soils were fabricated to closely resemble typical compositions and particle size distributions of North Sea marine sediments. The test sands varied according to their coarse particle fractions, with 0, 15 and 35% being retained on a 0·4 mm sieve. Testing was carried out at the very low stresses pertinent to pipeline interfaces, between 2·5 and 37·5 kPa, in both loose and dense states. The experimental results suggest a dependency of the interface shear strength on the stress level and relative density, with the coarse particle fraction playing a modest role. Surface characterisation and lack of volumetric deformation suggests that the shearing kinematic is predominantly grain sliding rather than rolling. Interface efficiency was largely constant despite some scatter due to variability in surface specimens. The distinct seams apparent on some of the polypropylene surfaces as inherent manufacturing artefacts had a negligible influence on interface strength. The relationship between interface strength, normalised roughness and Shore D hardness was assessed, discussed and compared with results from other works

Repeated automatic versus ambulatory blood pressure measurement:the effects of age and sex in a normal ageing population

Objectives To study blood pressure adaptation in relation to age and sex, In a subsample, laboratory blood pressure measurements were compared with ambulatory daytime blood pressure measurements to determine the degree of agreement between the two methods, The night-time blood pressure reduction was analysed as a function of blood pressure status, age and sex.Design A cross-sectional study in 469 healthy volunteers, aged 23-82 years, stratified for age, sex and educational level.Methods Laboratory blood pressure was measured automatically (Dinamap 8100) five times during a 20min recording session, Cardiovascular events in the medical history were identified in order to treat the cardiovascular event-free group separately in subsequent analyses, Within 3 weeks after laboratory blood pressure measurement, ambulatory blood pressure was measured for 24h in 135 volunteers from the main study.Results Both diastolic and systolic blood pressure varied markedly in a single measurement session as a function of age, independent of mean pressure level, After 15min no further blood pressure decrease was observed, On the basis of the average of the final two blood pressure measurements, 18.8% of the subjects were in the hypertensive range (WHO/ISH guidelines). Ambulatory blood pressure measurements were in accord with earlier findings and correlated 0.74 and 0.73 with laboratory diastolic and systolic blood pressure, respectively, but weighted kappa values indicated only moderate agreement (0.42 and 0.51), Women showed a more profound reduction in cnight-time blood pressure than did men.Conclusions There is a substantial change in blood pressure during a single measurement session which is greater in older age groups, The moderate agreement between the two methods of blood pressure measurement supports the notion that blood pressure measured in a single session has limited generalizability to average daytime levels in a population sample

Separating the effects of 24-hour urinary chloride and sodium excretion on blood pressure and risk of hypertension:Results from PREVEND

OBJECTIVE:Research into dietary factors associated with hypertension has focused on the sodium component of salt. However, chloride has distinct physiological effects that may surpass the effect of sodium on blood pressure. This study aims to separate the specific effects of chloride and sodium intake on blood pressure. METHODS:We studied 5673 participants from the Prevention of Renal and Vascular End-Stage Disease(PREVEND) study. Urinary chloride(uCl) and sodium(uNa) were measured in two 24-hour collections. We used generalized-linear-regression to evaluate the relation of uCl and uNa with baseline blood pressure and Cox-proportional-hazards-analysis to assess the association with hypertension. Multicollinearity was assessed with Ridge regression. RESULTS:Baseline 24-hour uCl was 135±39mmol and uNa was 144±54mmol. The correlation between uCl and uNa was high (Pearson's r = 0.96). UCl and uNa had similar non-significant positive and linear associations with blood pressure. In 3515 normotensive patients, 1021 patients developed hypertension during a median follow-up of 7.4 years. UCl and uNa had a comparable but non-significant J-shaped effect on the risk of hypertension. Adding both uCl and uNa to the same model produced instability, demonstrated by Ridge coefficients that converged or changed sign. The single index of uNa minus uCl showed a non-significant higher risk of hypertension of 2% per 10mmol/24-hour difference (HR1.02, 95%CI 0.98-1.06). CONCLUSION:UCl and uNa had similar positive but non-significant associations with blood pressure and risk of hypertension and their effects could not be disentangled. Hence, the alleged adverse effects of high salt intake could be due to sodium, chloride or both. This encourages further study into the effect of chloride in order to complement dietary recommendations currently focused on sodium alone