137 research outputs found

    Enhanced CO2 absorption kinetics in lithium silicate platelets synthesized by a sol–gel approach

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    Platelet-shaped lithium orthosilicate particles synthesized by a sol–gel approach employing the precursors lithium nitrate and colloidal silica displayed enhanced absorption kinetics for CO2 compared to the powders prepared by a solid-state reaction process involving Li2CO3 and silica. The sol–gel samples showed a CO2 absorption capacity of 350 mg g-1 at an absorption rate of 22.5 mg g-1 min-1, a value 70% higher than the rate of 13.2 mg g-1 min-1 measured with the solid-state samples under similar conditions. The higher sorption kinetics of CO2 by the sol–gel derived lithium orthosilicate could be attributed to the unique platelet morphology of the particles, which have a very small thickness. A porous carbon mesh coated with the sol–gel based particles exhibited CO2 absorption capacity of 150 mg g-1 at an absorption rate of 37.5 mg g-1 min-1. This supported absorbent also showed stable absorption and desorption performance for the 8 cycles examined in this study. The excellent absorption characteristics of the sol–gel prepared powders, more specifically the coated strips, provide a successful pathway for the commercialisation of these materials

    Measurement of nicotine withdrawal symptoms: linguistic validation of the Wisconsin Smoking Withdrawal Scale (WSWS) in Malay

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    <p>Abstract</p> <p>Background</p> <p>The purpose of the linguistic validation of the Wisconsin Smoking Withdrawal Scale (WSWS) was to produce a translated version in Malay language which was "conceptually equivalent" to the original U.S. English version for use in clinical practice and research.</p> <p>Methods</p> <p>A seven-member translation committee conducted the translation process using the following methodology: production of two independent forward translations; comparison and reconciliation of the translations; backward translation of the first reconciled version; comparison of the original WSWS and the backward version leading to the production of the second reconciled version; pilot testing and review of the translation, and finalization.</p> <p>Results</p> <p>Linguistic and conceptual issues arose during the process of translating the instrument, particularly pertaining to the title, instructions, and some of the items of the scale. In addition, the researchers had to find culturally acceptable equivalents for some terms and idiomatic phrases. Notable among these include expressions such as "irritability", "feeling upbeat", and "nibbling on snacks", which had to be replaced by culturally acceptable expressions. During cognitive debriefing and clinician's review processes, the Malay translated version of WSWS was found to be easily comprehensible, clear, and appropriate for the smoking withdrawal symptoms intended to be measured.</p> <p>Conclusions</p> <p>We applied a rigorous translation method to ensure conceptual equivalence and acceptability of WSWS in Malay prior to its utilization in research and clinical practice. However, to complete the cultural adaptation process, future psychometric validation is planned to be conducted among Malay speakers.</p

    The costs in provision of haemodialysis in a developing country: A multi-centered study

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    <p>Abstract</p> <p>Background</p> <p>Chronic Kidney Disease is a major public health problem worldwide with enormous cost burdens on health care systems in developing countries. We aimed to provide a detailed analysis of the processes and costs of haemodialysis in Sri Lanka and provide a framework for modeling similar financial audits.</p> <p>Methods</p> <p>This prospective study was conducted at haemodialysis units of three public and two private hospitals in Sri Lanka for two months in June and July 2010. Cost of drugs and consumables for the three public hospitals were obtained from the price list issued by the Medical Supplies Division of the Department of Health Services, while for the two private hospitals they were obtained from financial departments of the respective hospitals. Staff wages were obtained from the hospital chief accountant/chief financial officers. The cost of electricity and water per month was calculated directly with the assistance of expert engineers. An apportion was done from the total hospital costs of administration, cleaning services, security, waste disposal and, laundry and sterilization for each unit.</p> <p>Results</p> <p>The total number of dialysis sessions (hours) at the five hospitals for June and July were 3341 (12959) and 3386 (13301) respectively. Drug and consumables costs accounted for 70.4-84.9% of the total costs, followed by the wages of the nursing staff at each unit (7.8-19.7%). The mean cost of a dialysis session in Sri Lanka was LKR 6,377 (US56).Theannualcostofhaemodialysisforapatientwithchronicrenalfailureundergoing23dialysissessionoffourhoursdurationperweekwasLKR663,208994,812(US 56). The annual cost of haemodialysis for a patient with chronic renal failure undergoing 2-3 dialysis session of four hours duration per week was LKR 663,208-994,812 (US 5,869-8,804). At one hospital where facilities are available for the re-use of dialyzers (although not done during study period) the cost of consumables would have come down from LKR 5,940,705 to LKR 3,368,785 (43% reduction) if the method was adopted, reducing costs of haemodialysis per hour from LKR 1,327 at present to LKR 892 (33% reduction).</p> <p>Conclusions</p> <p>This multi-centered study demonstrated that the costs of haemodialysis in a developing country remained significantly lower compared to developed countries. However, it still places a significant burden on the health care sector, whilst possibility of further cost reduction exists.</p

    Bentham, Not Epicurus: The Relevance of Pleasure to Studies of Drug-Involved Pain

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    There is a disproportionate focus on pain over pleasure in policy-relevant research on drugs. This is unfortunate because theories of and findings on drug-involved pleasure can be used to inform knowledge of drug-involved pain. The cross-fertilization of theories and findings is bolstered by the availability of a conceptual framework that links drug-involved pain and pleasure in a comprehensive, powerful, simple, and instrumental manner. This article proposes such a framework. It consists of four types of drug-involved pain and pleasure: drug-specific corporal; drug-related corporal; economic; and, social. This quaternary scheme is illustrated with findings from four literatures, namely those on methamphetamine use; alcohol-related sexual contact among college students; resource transfer among drug users and dealers; and, relational and communal issues related to drugs. The article concludes with implications for the field

    Driving without wings: the effect of different digital mirror locations on the visual behaviour, performance and opinions of drivers

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    Drivers' awareness of the rearward road scene is critical when contemplating or executing lane-change manoeuvres, such as overtaking. Preliminary investigations have speculated on the use of rear-facing cameras to relay images to displays mounted inside the car to create ‘digital mirrors'. These may overcome many of the limitations associated with traditional ‘wing’ and rear-view mirrors, yet will inevitably effect drivers' normal visual scanning behaviour, and may force them to consider the rearward road scene from an unfamiliar perspective that is incongruent with their mental model of the outside world. We describe a study conducted within a medium-fidelity simulator aiming to explore the visual behaviour, driving performance and opinions of drivers while using internally located digital mirrors during different overtaking manoeuvres. Using a generic UK motorway scenario, thirty-eight experienced drivers conducted overtaking manoeuvres using each of five different layouts of digital mirrors with varying degrees of ‘real-world’ mapping. The results showed reductions in decision time for lane changes and eyes-off road time while using the digital mirrors, when compared with baseline traditional reflective mirrors, suggesting that digital displays may enable drivers to more rapidly pick up the salient information from the rearward road scene. Subjectively, drivers preferred configurations that most closely matched existing mirror locations, where aspects of real-world mapping were largely preserved. The research highlights important human factors issues that require further investigation prior to further development/implementation of digital mirrors within vehicles. Future work should also aim to validate findings within real-world on-road environments whilst considering the effects of digital mirrors on other important visual behaviour characteristics, such as depth perception

    Global, regional, and national comparative risk assessment of 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks, 1990-2015: A systematic analysis for the Global Burden of Disease Study 2015

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    Background: The Global Burden of Diseases, Injuries, and Risk Factors Study 2015 provides an up-to-date synthesis of the evidence for risk factor exposure and the attributable burden of disease. By providing national and subnational assessments spanning the past 25 years, this study can inform debates on the importance of addressing risks in context. Methods: We used the comparative risk assessment framework developed for previous iterations of the Global Burden of Disease Study to estimate attributable deaths, disability-adjusted life-years (DALYs), and trends in exposure by age group, sex, year, and geography for 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks from 1990 to 2015. This study included 388 risk-outcome pairs that met World Cancer Research Fund-defined criteria for convincing or probable evidence. We extracted relative risk and exposure estimates from randomised controlled trials, cohorts, pooled cohorts, household surveys, census data, satellite data, and other sources. We used statistical models to pool data, adjust for bias, and incorporate covariates. We developed a metric that allows comparisons of exposure across risk factors—the summary exposure value. Using the counterfactual scenario of theoretical minimum risk level, we estimated the portion of deaths and DALYs that could be attributed to a given risk. We decomposed trends in attributable burden into contributions from population growth, population age structure, risk exposure, and risk-deleted cause-specific DALY rates. We characterised risk exposure in relation to a Socio-demographic Index (SDI). Findings: Between 1990 and 2015, global exposure to unsafe sanitation, household air pollution, childhood underweight, childhood stunting, and smoking each decreased by more than 25%. Global exposure for several occupational risks, high body-mass index (BMI), and drug use increased by more than 25% over the same period. All risks jointly evaluated in 2015 accounted for 57·8% (95% CI 56·6–58·8) of global deaths and 41·2% (39·8–42·8) of DALYs. In 2015, the ten largest contributors to global DALYs among Level 3 risks were high systolic blood pressure (211·8 million [192·7 million to 231·1 million] global DALYs), smoking (148·6 million [134·2 million to 163·1 million]), high fasting plasma glucose (143·1 million [125·1 million to 163·5 million]), high BMI (120·1 million [83·8 million to 158·4 million]), childhood undernutrition (113·3 million [103·9 million to 123·4 million]), ambient particulate matter (103·1 million [90·8 million to 115·1 million]), high total cholesterol (88·7 million [74·6 million to 105·7 million]), household air pollution (85·6 million [66·7 million to 106·1 million]), alcohol use (85·0 million [77·2 million to 93·0 million]), and diets high in sodium (83·0 million [49·3 million to 127·5 million]). From 1990 to 2015, attributable DALYs declined for micronutrient deficiencies, childhood undernutrition, unsafe sanitation and water, and household air pollution; reductions in risk-deleted DALY rates rather than reductions in exposure drove these declines. Rising exposure contributed to notable increases in attributable DALYs from high BMI, high fasting plasma glucose, occupational carcinogens, and drug use. Environmental risks and childhood undernutrition declined steadily with SDI; low physical activity, high BMI, and high fasting plasma glucose increased with SDI. In 119 countries, metabolic risks, such as high BMI and fasting plasma glucose, contributed the most attributable DALYs in 2015. Regionally, smoking still ranked among the leading five risk factors for attributable DALYs in 109 countries; childhood underweight and unsafe sex remained primary drivers of early death and disability in much of sub-Saharan Africa. Interpretation: Declines in some key environmental risks have contributed to declines in critical infectious diseases. Some risks appear to be invariant to SDI. Increasing risks, including high BMI, high fasting plasma glucose, drug use, and some occupational exposures, contribute to rising burden from some conditions, but also provide opportunities for intervention. Some highly preventable risks, such as smoking, remain major causes of attributable DALYs, even as exposure is declining. Public policy makers need to pay attention to the risks that are increasingly major contributors to global burden. Funding: Bill & Melinda Gates Foundation
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