61 research outputs found

    A Global Challenge: Sustainability of Submicrometer PEO and PVP Fiber Production

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    The field of submicrometer polymeric production currently has a predominant research focus on morphology and application. In comparison, the sustainability of the manufacture of submicrometer polymeric fibers, specifically the energy efficiency, is less explored. The principles of Green Chemistry and Green Engineering outline frameworks for the manufacture of “greener” products, where the most significant principles in the two frameworks are shown to be centered on energy efficiency, material wastage, and the use of non-hazardous materials. This study examines the power consumption during the production of Polyethylene oxide (PEO) and Polyvinylpyrrolidone (PVP) submicrometer fibers under magnitudes of the key forming parameters to generate fibers via pressure spinning. The energy consumption, along with the fiber diameter, and production rate during the manufacture of fibers is predominantly attributed to the characteristics of polymeric solutions utilized

    PSS19 COST-EFFECTIVENESS OF AGE-RELATED MACULAR DEGENERATION: A MODEL

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    SF-6D utility values for the better- and worse-seeing eye for health states based on the Snellen equivalent in patients with age-related macular degeneration

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    Objective: Economic evaluations in wet age-related macular degeneration (ARMD) is hampered as often utility values for solely one eye are used, mostly the better-seeing eye (BSE). Moreover, frequently chosen methods rely on patient values and/or disease specific measures, while economic evaluations prefer generic quality of life (QoL) measures based on societal preferences. The generic QoL utility instrument EQ-5D has shown to be insensitive for differences in visual acuity. The aim of this study was therefore to provide societal utility values, using the generic SF-6D, for health states acknowledging both BSE and worse-seeing eye (WSE). Methods: SF-6D utility values of 191 ARMD patients (≤65 years) with 153 follow-up measures at 1 year were used to fill health states defined by the combination of BSE and WSE using Snellen equivalents; no visual loss (≥20/40), mild-moderate (20/200) and severe (≤20/200). Results: QoL utilities were estimated for the SF-6D, ranging from 0.740 for ARMD patients without visual loss to 0.684 for patients with a combination of mild-moderate visual loss in their BSE and severe visual loss in their WSE. Conclusion: Societal utility values are provided for ARMD patients using the generic QoL instrument SF-6D for visual acuity health states based on both BSE and WSE. The range of the values is smaller than previous elicited utilities with the disease-specific VisQoL. Besides, the utility values are placed on a more realistic position on the utility scale, and SF-6D utility values avoid the problem associated with the interpretation of disease-specific utility values

    Six and eight weeks injection frequencies of bevacizumab are non-inferior to the current four weeks injection frequency for quality of life in neovascular age-related macular degeneration: a randomized controlled trial

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    Purpose: Patients with neovascular age-related macular degeneration (nARMD) will not deteriorate on visual acuity and retinal thickness when treated with bevacizumab injection frequencies of 6 or 8 weeks compared to 4 weeks. This study aimed to investigate this non-inferiority in quality of life (QoL). We hypothesized that less frequent bevacizumab injections are not inferior regarding patients reported QoL. Methods: Patients were randomized to bevacizumab every 4 (n = 64), 6 (n = 63), and 8 weeks (n = 64). Patients were at least 65 years old, have a best-corrected visual acuity of 20/200 to 20/20, no previous ARMD treatment and active leakage. Vision-related QoL questionnaire NEI VFQ-39 was used to assess QoL at baseline and after 1 year. General QoL questionnaire SF-36 was included for secondary analysis. Multilevel analyses were performed, correcting for age, gender and baseline. Results: The 6 (3.68; 95% CI − 0.63 to 8.00) and 8 (2.15; 95% CI − 2.26 to 6.56) weeks bevacizumab regimens resulted in non-inferior QoL differences compared to 4 weeks on the NEI VFQ-39. Also on the SF-36 the differences were well within the non-inferiority limits. Conclusion: Non-inferiority of the 6 and 8 weeks frequencies was demonstrated compared to 4 weeks on vision-related and general QoL in patients with nARMD. These results are in line with previously published results of lower frequency injections regarding visual acuity and central retinal thickness. Lower injection frequency may reduce burden, side effects, and treatment costs. In consideration of these results, 8 weeks frequency injections of intravitreal bevacizumab could be considered in patients with nARMD

    A genetic case-control study confirms the implication of SMAD7 and TNF locus in the development of proliferative vitreoretinopathy

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    PURPOSE: Proliferative vitreoretinopathy (PVR) is still the major cause of failure of retinal detachment (RD) surgery and although the risk for developing this complication is associated with some clinical characteristics, the correlation is far from absolute, raising the possibility of genetic susceptibility. The objective of this study was to analyze the genetic contribution to PVR in patients undergoing RD surgery, the Retina 4 Project. METHODS: A candidate gene association study was conducted in 2006 in a Spanish population of 450 patients suffering from primary rhegmatogenous RD. Replication was carried out in a larger population undergoing RD surgery at several European centers among 546 new patients. Single nucleotide polymorphism (SNP) of 30 genes known to be involved with inflammation were analyzed. For replication stage, those genes previously detected as significantly associated with PVR were genotyped. Distribution of allelic and haplotypic frequencies in case and control group were analyzed. Single and haplotypic analysis were assessed. The Rosenberg two-stage method was used to correct for single and multiple analyses. RESULTS: After correction for multiple comparisons, four genes were significantly associated with PVR: SMAD7 (P = 0.004), PIK3CG (P = 0.009), TNF locus (P = 0.0005), and TNFR2 (P = 0.019) In the European sample, replication was observed in SMAD7 (P = 0.047) and the TNF locus (P = 0.044). CONCLUSIONS: These results confirm the genetic contribution to PVR and the implication of SMAD7 and TNF locus in the development of PVR. This finding may have implications for understanding the mechanisms of PVR and could provide a potential new therapeutic target for PVR prophylaxis

    ESTIMATION OF FARM LEVEL TECHNICAL EFFICIENCY AND ITS SOCIO-ECONOMIC DETERMINANTS IN VANILLA PRODUCTION IN KANDY DISTRICT, SRI LANKA

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    Vanilla is one of the economically important crops in Sri Lanka although it is mainly confined as a home garden crop grown in mid and low country wet zone. Farmer productivity is one of the most important concerns in vanilla cultivation. Thus, the productivity of Vanilla farmers can be raised by improvement in efficiency in the short run. As a result of the near absence of empirical information on farm-level technical efficiency in small scale Vanilla Production in the country generally and Kandy District in particular, a Stochastic Frontier function which incorporated inefficiency factors was estimated using a Maximum Likelihood technique to provide estimates of technical efficiency and its determinants using data obtained from 80 Vanilla farmers in Ganga Ihala Korale Divisional Secretariat division since it has one of the largest numbers of small-holder vanilla producers in the country. The results reveal that Vanilla farmers are not fully technically efficient and the mean technical efficiency estimated is 37.32%. Estimated results of the inefficiency model show that experience and educational level of the vanilla farmers significantly influence the farmers ‘efficiency positively whereas age of the farmers contributes to increase the inefficiency. The findings imply that policies that would encourage youth to engage in vanilla farming and improvement in human capital should be made and implemented.Keywords: Kandy District, Maximum Like hood estimation, Stochastic frontier model, Technical efficiency, Vanilla farmer

    Social sciences research in neglected tropical diseases 2: A bibliographic analysis

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    The official published version of the article can be found at the link below.Background There are strong arguments for social science and interdisciplinary research in the neglected tropical diseases. These diseases represent a rich and dynamic interplay between vector, host, and pathogen which occurs within social, physical and biological contexts. The overwhelming sense, however, is that neglected tropical diseases research is a biomedical endeavour largely excluding the social sciences. The purpose of this review is to provide a baseline for discussing the quantum and nature of the science that is being conducted, and the extent to which the social sciences are a part of that. Methods A bibliographic analysis was conducted of neglected tropical diseases related research papers published over the past 10 years in biomedical and social sciences. The analysis had textual and bibliometric facets, and focussed on chikungunya, dengue, visceral leishmaniasis, and onchocerciasis. Results There is substantial variation in the number of publications associated with each disease. The proportion of the research that is social science based appears remarkably consistent (<4%). A textual analysis, however, reveals a degree of misclassification by the abstracting service where a surprising proportion of the "social sciences" research was pure clinical research. Much of the social sciences research also tends to be "hand maiden" research focused on the implementation of biomedical solutions. Conclusion There is little evidence that scientists pay any attention to the complex social, cultural, biological, and environmental dynamic involved in human pathogenesis. There is little investigator driven social science and a poor presence of interdisciplinary science. The research needs more sophisticated funders and priority setters who are not beguiled by uncritical biomedical promises

    Improving pulse crops as a source of protein, starch and micronutrients

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    Pulse crops have been known for a long time to have beneficial nutritional profiles for human diets but have been neglected in terms of cultivation, consumption and scientific research in many parts of the world. Broad dietary shifts will be required if anthropogenic climate change is to be mitigated in the future, and pulse crops should be an important component of this change by providing an environmentally sustainable source of protein, resistant starch and micronutrients. Further enhancement of the nutritional composition of pulse crops could benefit human health, helping to alleviate micronutrient deficiencies and reduce risk of chronic diseases such as type 2 diabetes. This paper reviews current knowledge regarding the nutritional content of pea (Pisum sativum L.) and faba bean (Vicia faba L.), two major UK pulse crops, and discusses the potential for their genetic improvement
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