721 resultados para Scientific journal literature


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Aim: To assess the sample sizes used in studies on diagnostic accuracy in ophthalmology. Design and sources: A survey literature published in 2005. Methods: The frequency of reporting calculations of sample sizes and the samples' sizes were extracted from the published literature. A manual search of five leading clinical journals in ophthalmology with the highest impact (Investigative Ophthalmology and Visual Science, Ophthalmology, Archives of Ophthalmology, American Journal of Ophthalmology and British Journal of Ophthalmology) was conducted by two independent investigators. Results: A total of 1698 articles were identified, of which 40 studies were on diagnostic accuracy. One study reported that sample size was calculated before initiating the study. Another study reported consideration of sample size without calculation. The mean (SD) sample size of all diagnostic studies was 172.6 (218.9). The median prevalence of the target condition was 50.5%. Conclusion: Only a few studies consider sample size in their methods. Inadequate sample sizes in diagnostic accuracy studies may result in misleading estimates of test accuracy. An improvement over the current standards on the design and reporting of diagnostic studies is warranted.

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The knowledge of the chemical stability as a function of the temperature of ionic liquids (ILs) in the presence of other molecules such as water is crucial prior to developing any no GO industrial application and process involving these novel materials. Fluid phase equilibria and density over a large range of temperature and composition can give basic information on IL purity and chemical stability. The IL scientific community requires accurate measurements accessed from reference data. In this work, the stability of different alkyl sulfate-based ILs in the presence of water and various alcohols (methanol, ethanol, 1-butanol, and 1-octanol) was investigated to understand their stability as a function of temperature up to 423.15 K over the hydrolysis and transesterification reactions, respectively. From this investigation, it was clear that methyl sulfate- and ethyl sulfate-based ILs are not stable in the presence of water, since hydrolysis of the methyl sulfate or ethyl sulfate anions to methanol or ethanol and hydrogenate anion is undoubtedly observed. Such observations could help to explain the differences observed for the physical properties published in the literature by various groups. Furthermore, it appears that a thermodynamic equilibrium process drives these hydrolysis reactions. In other words, these hydrolysis reactions are in fact reversible, providing the possibility to re-form the desired alkyl sulfate anions by a simple transesterification reaction between hydrogen sulfate-based ILs and the corresponding alcohol (methanol or ethanol). Additionally, butyl sulfate- and octyl sulfate-based ILs appear to follow this pattern but under more drastic conditions. In these systems, hydrolysis is observed in both cases after several months for temperatures up to 423 K in the presence of water. Therein, the partial miscibility of hydrogen sulfate-based ILs with long chain alcohols (1-butanol and 1-octanol) can help to explain the enhanced hydrolytic stability of the butyl sulfate- and octyl sulfate-based ILs compared with the methyl or ethyl sulfate systems. Additionally, rapid transesterification reactions are observed during liquid-liquid equilibrium studies as a function of temperature for binary systems of (hydrogen sulfate-based ionic liquids + 1-butanol) and of (hydrogen sulfate-based ionic liquids + 1-octanol). Finally, this atom-efficient catalyst-free transesterification reaction between hydrogen sulfate-based ILs and alcohol was then tested to provide a novel way to synthesize new ILs with various anion structures containing the alkyl sulfate group.

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Background: Chronic kidney disease (CKD) is a complex, long-term condition occurring in all age groups. It has been reported that the incidence of renal replacement therapy in young people is 7-8 per million population. Notwithstanding those individuals who may receive a donor kidney, many individuals may be disenfranchised by perceptions of helplessness and feelings of powerlessness against a backdrop of diminished health outlook, consequently impacting on capacity for effective coping. Aim: The aim of this review is to explore how young people cope with CKD. Methods: Three hundred and thirty-seven abstracts were identified. Sixty-three papers were cross-examined using a Critical Appraisal Skills Checklist Tool. Results: Young people face various demands; these may be episodic or ongoing, depending on health and circumstance. The themes this review uncovers are: 'Lack of a Coping Definition'; 'Coping Strategies in Young People'; and 'Barriers to the Understanding of Coping in Young People'. Conclusion: More qualitative research is vital to retrieve 'real-life' perceptions from young people coping with kidney disease to identify how care should be made more explicit for them. © 2012 European Dialysis and Transplant Nurses Association/European Renal Care Association.

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Introduction: Cachexia is a major cause of morbidity and mortality in people who have end-stage renal disease (ESRD). The majority of research into cachexia in ESRD has focused on the biological aspects of the syndrome and potential treatment modalities. While this research is necessary, it predominately focuses on the physical impact of cachexia in ESRD. The multi-dimensional psychosocial ramifications of this syndrome have been highlighted in other end-stage illness trajectories, but have not been systematically explored in persons who have ESRD. Aim: This paper discusses why this research is necessary, alongside further studies to help define the pathophysiology of this syndrome. Conclusion: The rich insightful data gained from understanding the patients' illness experience will positively contribute to the limited knowledge base available and inform future holistic patient-centred care delivery which recognises and responds to not only the biological but also the psychosocial impact of cachexia. © 2013 European Dialysis and Transplant Nurses Association/European Renal Care Association.

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There is a wealth of research exploring the psychological consequences of infertility and assisted reproduction technology: a substantial body of sociological and anthropological work on ‘reproductive disruptions’ of many kinds and a small but growing literature on patient perspectives of the quality of care in assisted reproduction. In all these fields, research studies are far more likely to be focused on the understandings and experiences of women than those of men. This paper discusses reasons for the relative exclusion of men in what has been called the ‘psycho-social’ literature on infertility, comments on research on men from psychological and social perspectives and recent work on the quality of patient care, and makes suggestions for a reframing of the research agenda on men and assisted reproduction. Further research is needed in all areas, including: perceptions of infertility and infertility treatment seeking; experiences of treatment; information and support needs; decisions to end treatment; fatherhood post assisted conception; and the motivation and experiences of sperm donors and men who seek fatherhood through surrogacy or co-parenting. This paper argues for multimethod, interdisciplinary research that includes broader populations of men which can contribute to improved clinical practice and support for users of assisted reproduction treatment

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This article explores congenital cataract with emphasis on the effectiveness of early screening, diagnosis, pre-assessment and the timing of surgery. Congenital cataract is a rare condition. It is estimated that approximately 200,000 children worldwide are blind from cataract and further government funding is essential to treat and reduce this treatable global cause of blindness (WHO 1999).

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It is estimated that 60% of patients diagnosed with head and neck cancer will receive radiotherapy at some stage in their disease trajectory. The aim of this literature review was to find and analyse papers pertaining to the lived experiences of patients with head and neck cancer receiving radiotherapy. The review identified a limited number of high-quality research papers focusing on this topic, with only 10 papers fitting the inclusion/exclusion criteria. The majority of the investigative studies were not generalisable owing to small sample sizes and many of them being conducted in only one centre. However, the findings do highlight and contribute to the understanding of the lived experiences of this patient group and provide some insight into the unique physical, social, and psychological difficulties they encounter as a result of their treatment. There appears to be a need for further high-level research into these patients, particularly focusing on the provision of support and information prior to, during, and following radiotherapy. Further attention needs to be paid to preparing patients for the slow recovery following radiotherapy. Interventional studies are also required to develop clinical guidelines and protocols that can assist health professionals in meeting the holistic needs of this patient group.

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Supported decision making (SDM) refers to the process of supporting people, whose decision making ability may be impaired, to make decisions and so promote autonomy and prevent the need for substitute decision making. There have been developments in SDM but mainly in the areas of intellectual disabilities and end-of-life care rather than in mental health. The main aim of this review was to provide an overview of the available evidence relevant to SDM and so facilitate discussion of how this aspect of law, policy and practice may be further developed in mental health services. The method used for this review was a Rapid Evidence Assessment which involved: developing appropriate search strategies; searching relevant databases and grey literature; then assessing, including and reviewing relevant studies. Included studies were grouped into four main themes: studies reporting stakeholders’ views on SDM; studies identifying barriers to the implementation of SDM; studies highlighting ways to improve implementation; and studies on the impact of SDM. The available evidence on implementation and impact, identified by this review, is limited but there are important rights-based, effectiveness and pragmatic arguments for further developing and researching SDM for people with mental health problems.

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Previous research with parents of preterm and low-birth weight infants admitted to the Neonatal Intensive Care Unit (NICU) has indicated the following: (i) parents are at risk of experiencing stress associated with the NICU environment; (ii) parents are at risk of short- and longer-term psychological distress; and (iii) the family is at risk of longer-term stress and strain. However, parents of infants admitted to the NICU for surgery are an under-researched population. This paper provides an overview of the current literature in relation to this issue. The results highlight the paucity of research conducted with parents of infants admitted to the NICU for surgery. A number of gaps and limitations were also identified in the current literature, including a lack of examination why some parents cope better than others, and a focus solely on parents of preterm and low birth weight infants. To conclude, further research with parents of infants who had surgery in the first few weeks of life is needed. Such information could help inform clinicians caring for these infants and their families, and would enable identification of those parents and families most at risk.