174 research outputs found

    An overview on green house gas emission characteristics and energy evaluation of ocean energy systems from life cycle assessment and energy accounting studies

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    An analysis has been made as regards emission characteristics of ocean energy systems from life cycle assessment and scope of energy availability from energy accounting studies. Assessment tools developed and standardized were the indices like scope of Green house gases (GHG) emission per kWh power generation, percentage of CO2 saved compared to coal fired power station and the energy payback period. Emission characteristics of ocean energy systems were also compared with that from solar power, bio-fuels and wind energy systems. Four case studies were made comprising of wave energy converters, Ocean Thermal Energy Conversion (OTEC) system and tidal energy. It could be observed that CO2 emission percentage saved from ocean energy schemes were more than 95 per cent; and energy payback period varied between one year and a little higher than two years, depending on the type of the device

    A case study of a hypothetical 100 MW OTEC plant analyzing the prospects of OTEC technology

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    A hypothetical case study has been made of a 100 MW OTEC plant, which would require around 400 m3/sec of warm water feed (with 200 m3/sec of cold water feed) and resulted in the following data: CO2 saving compared to coal power plant, as determined from lifecycle assessment (LCA)studies, would be 98.62 % for CC-OTEC, 97.41 % for the hybrid type, and 94.4 % for OC-OTEC. Energy payback period value would be 1.33 years. Cost of power generation from NPV concept of such plant is estimated to be of 2.9 p/kWh. 172,800 m3 of potable water/day could be available from OC-OTEC (but none from CC-OTEC though a hybrid type may yield appreciable potable water). More than 68,000 kg shellfish/day could be availed for all types of 100 MW OTEC. Upwelling of the nutrient rich cold water along with abundant plankton from sea-bottom and the mixed discharge of it in the ocean during OTEC operations is likely to help growth of the oceans’ flora and fauna for the abundant supply of seafood. But the danger posed from simultaneous upwelling of toxic algal bloom endangering the marine species, are also apprehended. However, by and large positive marine species growth has been opined. Such increased species growth becomes instrumental in burying CO2 in the deep ocean floor with the carcasses of dead marine species grown. This phenomenon known as sequestering of CO2, appreciably increases the ocean’s CO2 storage capability and thereby in addressing the problem of global warming. This is in addition to the amount of CO2 saved from use of alternate energy source on OTEC, against the conventional fossil fuel resources. Upwelling of cold water may be utilized in cold storages/air conditioning saving 600 times the power required for running the same. Hydrogen production, as may be made at expense of the net power generated, from a 100 MW plant, would amount to over 35,000 kg/day or 20,000 kg of NH3/day. 21,773 kg of CO2/day from OC-OTEC (also from the hybrid type but not for CC-OTEC) would be available, which can be utilized as raw material for soda ash manufacture/urea production (along with NH3 as may be availed from H2 production). Also a huge quantity of oxygen enriched air – near 33 % O2 content, against 20.93 % of normal air may be availed. 188,812 kg/day of methanol utilizing the H2, as may be generated can thereby be the resource raw material for petrochemical industries, opening up the scope of availability of a chemical hub in the vicinity of the OTEC plant. Such OTEC plants can help sustainable development, particularly small island developing states (SIDS), arresting coral bleaching (decreasing acid rains etc.), and generating employment; and also help in reducing global warming from sequestering of CO2, in addition to saving CO2 emission compared to conventional fossil fuel power generators

    Association between HbA1c and the development of cystic fibrosis‐related diabetes

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    Aims To examine HbA1c as a predictor of risk for future development of cystic fibrosis‐related diabetes and to assess the association with the development of retinopathy in people with cystic fibrosis‐related diabetes. Methods A 7‐year retrospective longitudinal study was conducted in 50 adults with cystic fibrosis, comparing oral glucose tolerance test results with HbA1c values in predicting the development of cystic fibrosis‐related diabetes. Retinal screening data were also compared with HbA1c measurements to assess microvascular outcome. Results An HbA1c value ≥37 mmol/mol (5.5%; hazard ratio 3.49, CI 1.5–8.1) was significantly associated with the development of dysglycaemia, as defined by the oral glucose tolerance test over a 7‐year period. Severity of diabetic retinopathy was associated with a higher HbA1c and longer duration of cystic fibrosis‐related diabetes. Conclusion There is a link between HbA1c level and the future development of dysglycaemia in cystic fibrosis based on oral glucose tolerance test, as well as microvascular outcomes. Although current guidance does not advocate the use of HbA1c as a diagnostic tool in cystic fibrosis‐related diabetes, it may be of clinical use in determining individuals at risk of future development of cystic fibrosis‐related diabetes

    A pilot study investigating the effects of a manuka honey sinus rinse compared to a standard sinus rinse on sino-nasal outcome test scores in cystic fibrosis patients

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    Background: People with cystic fibrosis (CF) are prone to bacterial respiratory infections; these are often antibiotic resistant, are difficult to treat, and impact on the quality of life and lung function. The upper respiratory tract can act as a reservoir for these pathogens, and as part of clinical care, sinus rinses are used to alleviate symptoms in the upper airway. We have developed a sinus rinse containing manuka honey, to identify whether it can help improve symptoms or reduce the bacterial load. Methods: We will undertake a randomised controlled trial where 30 adults with CF will be recruited and randomised to either the control or intervention group. Both groups will follow a sinus rinse protocol for 30 days (± 7 days); the control group will use the standard of care rinse, and the intervention group will use a manuka honey rinse. Both groups will provide samples at day 0 and day 30. The primary outcome measure will be a change in the 22-item Sino-Nasal Outcome Test (SNOT-22) score. Secondary outcomes will include changes to quality of life (questionnaire), bacterial load/community composition, and sputum viscosity. Discussion: This trial will look at the use of a manuka honey-infused sinus rinse solution on patients diagnosed with cystic fibrosis (CF) suffering with sinusitis; it will allow us to determine the efficacy of the manuka honey sinus rinse compared to standard rinse and will allow us to determine if molecular bacterial diversity analysis will provide in-depth information beyond the usual conventional microbiological. It will allow us to determine the feasibility of recruiting participants to this type of trial, allow us to check participant compliance with the protocol, and inform future studies. Trial registration: Approval was obtained from the Research Ethics Committee Wales REC7 reference 18/WA/0319. Results of this study will be published at international conferences and in peer-reviewed journals; they will also be presented to the relevant stakeholders and research networks

    Development of the CFQ-R-8D: estimating utilities from the cystic fibrosis questionnaire-revised

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    Objective Cystic fibrosis (CF) limits survival and negatively affects health-related quality of life (HRQOL). Cost-effectiveness analysis (CEA) may be used to make reimbursement decisions for new CF treatments; however, generic utility measures used in CEA, such as EQ-5D, are insensitive to meaningful changes in lung function and HRQOL in CF. Here we develop a new, CF disease–specific, preference-based utility measure based on the adolescent/adult version of the Cystic Fibrosis Questionnaire-Revised (CFQ-R), a widely used, CF-specific, patient-reported measure of HRQOL. Methods Blinded CFQ-R data from 4 clinical trials (NCT02347657, NCT02392234, NCT01807923, and NCT01807949) were used to identify discriminating items for a classification system using psychometric (eg, factor and Rasch) analyses. Thirty-two health states were selected for a time-trade-off (TTO) exercise with a representative sample of the UK general population. TTO utilities were used to estimate a preference-based scoring algorithm by regression analysis (Tobit models with robust standard errors clustered on participants with censoring at −1). Results A classification system with 8 dimensions (CFQ-R-8D; Physical Functioning, Vitality, Emotion, Role Functioning, Breathing Difficulty, Cough, Abdominal Pain, and Body Image) was generated. TTO was completed by 400 participants (mean age, 47.3 years; 49.8% female). Among the regression models evaluated, the Tobit heteroscedastic–ordered model was preferred, with a predicted utility range from 0.236 to 1, no logical inconsistencies, and a mean absolute error of 0.032. Conclusion The CFQ-R-8D is the first disease-specific, preference-based scoring algorithm for CF, enabling estimation of disease-specific utilities for CEA based on the well-validated and widely used CFQ-R

    Cardiac regeneration: different cells same goal

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    Cardiovascular diseases are the leading cause of mortality, morbidity, hospitalization and impaired quality of life. In most, if not all, pathologic cardiac ischemia ensues triggering a succession of events leading to massive death of cardiomyocytes, fibroblast and extracellular matrix accumulation, cardiomyocyte hypertrophy which culminates in heart failure and eventually death. Though current pharmacological treatment is able to delay the succession of events and as a consequence the development of heart failure, the only currently available and effective treatment of end-stage heart failure is heart transplantation. However, donor heart availability and immunorejection upon transplantation seriously limit the applicability. Cardiac regeneration could provide a solution, making real a dream of both scientist and clinician in the previous century and ending an ongoing challenge for this century. In this review, we present a basic overview of the various cell types that have been used in both the clinical and research setting with respect to myocardial differentiation
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