997 resultados para Advanced polymers
Resumo:
Artificial riboflavin receptors adapted to aqueous environments were studied for their ability to selectively extract riboflavine (Rf) from three types of beverages i.e. milk, beer and a multivitamin mixture. The basic receptor was first prepared by molecular imprinting in nonaqueous medium using a hydrogen-bond donor-acceptor-donor functional monomer (2,6-bis(acrylamido)pyridine), complementary to the imide motif of the template, riboflavin tetra-acetate as template and pentaerythritol triacrylate (PETA) as a hydrophilic cross-linking monomer. The polymer was then packed in columns and used for extraction of riboflavine from beverages. Riboflavine (Rf) was selectively removed from milk and an artificial vitamin mixture but the nonspecific binding was still significant, as judged from the binding of Rf to a control nonimprinted polymer. In order to suppress this nonspecific binding, attempts to hydrolytically hydrophilize the polymer matrix were performed. The preferred approach consisted in a controlled base hydrolysis of pendent unreacted acrylate groups, using hydroxides with differently sized counterions as reagents. This resulted in a decreased binding of Rf to both polymers, but to an equal extent implying a preferential suppression of the nonspecific contribution to the binding. The hydrophilized polymers, when subjected to beer, showed larger imprinting factors at lower phase ratios compared to the nontreated polymers and a maximum removal of 86% compared to 47% for the nonimprinted control polymer.
Resumo:
Using caffeic acid and p-hydroxybenzoic acid as templates, two molecularly imprinted polymers (MIPs) were prepared that were used for isolation of polyphenols from olive mill waste water samples (OMWWs) without previous pre-treatment. For the preparation of the caffeic acid MIPs 4-vinylpyridine, allylurea, allylaniline and methacrylic acid were tested as functional monomers, ethylene glycol dimethylacrylate (EDMA), pentaerythritol trimethylacrylate (PETRA) and divinylbenzene 80 (DVB80) as cross-linkers and tetrahydrofuran as porogen. For p-hydroxybenzoic acid 4-vinylpyridine, allylurea and allylaniline were tested as functional monomers, EDMA and PETRA as cross-linkers and acetonitrile as porogen. The performance of the synthesized polymers was evaluated against seven structurally related compounds by means of polymer-based HPLC. The two polymers that presented the most interesting properties were further evaluated by batch rebinding and from the derived isotherms their capacity and binding strength were determined. Using solid-phase extraction (SPE), their ability to recognize and bind the template molecule from an aqueous solution as well as the pH dependence of the binding strength were explored. After establishing the best SPE protocol, an aqueous model mixture of compounds and a raw OMWWs sample were loaded on the two best polymers. The result of the consecutive use of the two polymers on the same sample was explored. It was concluded that acidic conditions favour the recognition abilities of both polymers and that they can be used for a quick and efficient isolation of the polyphenol fraction directly from raw OMWW.
Resumo:
Purpose/Objectives: To explore healthcare professionals' experience, understanding, and perception of the needs of patients with cachexia in advanced cancer.
Research Approach: A qualitative approach based on symbolic interactionism.
Setting: A regional cancer center in a large teaching hospital in the United Kingdom.
Participants: 34 healthcare professionals who had experience providing care to patients with cachexia in advanced cancer.
Methodologic Approach: Data collection consisted of two phases: focus group and semistructured interviews. Interviews were digitally recorded and transcribed verbatim for analysis. This article reports on findings from the second phase of data collection.
Findings: Analysis revealed that professional approaches to cachexia were influenced by three overarching and interthinking themes: knowledge, culture, and resources. Healthcare professionals commonly recognized the impact of the syndrome; however, for nonpalliative healthcare professionals, a culture of avoidance and an overreliance on the biomedical model of care had considerable influence on the management of cachexia in patients with advanced cancer.
Conclusions: Cachexia management in patients with advanced cancer can be difficult and is directed by a variable combination of the influence of knowledge, culture of the clinical area, and available resources. Distinct differences exist in the management of cachexia among palliative and nonpalliative care professionals.
Interpretation: This study presented a multiprofessional perspective on the management of cachexia in patients with advanced cancer and revealed that cachexia is a complex and challenging syndrome that needs to be addressed from a holistic model of care.
Knowledge Translation: Cachexia management in patients with advanced cancer is complex and challenging and is directed by a combination of variables. An overreliance on the biomedical model of health and illness occurs in the management of cachexia in patients with advanced cancer. Cachexia needs to be addressed from a holistic model of care to reflect the multidimensional needs of patients and their families.
Resumo:
Objectives: To evaluate a booklet on comfort care in dementia from the perspective of family with relevant experience, and assess nursing home resident and family factors associated with evaluations. Design: Retrospective study. Setting: Long term care facilities in French-speaking Canada, and the Netherlands and Italy.
Participants: Bereaved family (n = 138).
Measurements: An 8-item scale assessed the booklet's acceptability. Usefulness was rated on a 0 to 10 scale, and perceived usefulness referred to usefulness if family had had the booklet during the resident's stay. Families indicated preferred ways of obtaining, and the most appropriate time to get the booklet.
Results: Almost all families (94%) perceived the booklet as useful. Canadian and Dutch families evaluated the booklet's contents and format favorably, whereas Italian families' evaluations were less favorable. Almost all families endorsed roles for physicians or nurses and about half additionally accepted availability through own initiative, in print or through the Internet. Preference of timing was highly variable. Better acceptability, usefulness, and availability through own initiative were independently associated with non-Italian nationality, presence of more physical signs discussed in the booklet, feeling ill-prepared, and higher satisfaction with care. A preference of receiving the booklet early was more likely in Italian families, those without university education, and those involved with older residents.
Conclusion: The booklet is suitable to inform Dutch and Canadian families on comfort care in dementia, but implementation in Italy requires further consideration. The booklet may be integrated in advance care planning in long term care, and made available outside long term care settings to serve families who wish to be informed early. © 2012 American Medical Directors Association, Inc.
Keywords: Decision aid; decision making; advance care planning; palliative care; nursing homes; dementia.
Resumo:
The purpose of this study was to explore the care processes experienced by community-dwelling adults dying from advanced heart failure, their family caregivers, and their health-care providers. A descriptive qualitative design was used to guide data collection, analysis, and interpretation. The sample comprised 8 patients, 10 informal caregivers, 11 nurses, 3 physicians, and 3 pharmacists. Data analysis revealed that palliative care was influenced by unique contextual factors (i.e., cancer model of palliative care, limited access to resources, prognostication challenges). Patients described choosing interventions and living with fatigue, pain, shortness of breath, and functional decline. Family caregivers described surviving caregiver burden and drawing on their faith. Health professionals described their role as trying to coordinate care, building expertise, managing medications, and optimizing interprofessional collaboration. Participants strove towards 3 outcomes: effective symptom management, satisfaction with care, and a peaceful death. © McGill University School of Nursing.
Resumo:
Background: Families of patients with advanced dementia need to be informed about the course of the dementia and comfort care. Conditional for health care providers educating families is their knowledge and comfort in family education. Methods: Perceived usefulness and acceptability of a Canadian family booklet explaining possible complications and comfort care in dementia was assessed by physicians and nurses caring for dementia patients in 14 nursing homes in Lombardy, Italy and 21 in the Netherlands. The practitioners received a questionnaire and translated versions adapted to local practice where needed. In 10 of 21 Dutch homes, physicians evaluated only the original Canadian version in English. A 15-item scale assessed the booklet's acceptability, for example, to inform families, or for educational purposes. Perceived usefulness referred to proportion of families of dementia patients for whom the booklet would be useful. A total of 168 evaluations were available for multivariable regression analyses. Results: The practitioners anticipated that the booklet would be useful for most families. Evaluation of the Dutch translation of the booklet was similar to the English version. Country (Netherlands) and profession (nurses) were independently associated with better acceptability. Usefulness was perceived as better by Italian respondents and nurses, but only in analyses unadjusted for the higher educational needs of these respondents. Conclusion: Overall, the concept of written information on comfort care was appreciated by practitioners of European countries differing in attitudes toward end-of-life care. A booklet may help practitioners, and in particular nurses, in providing comfort care for dementia patients and their families. © Copyright 2011, Mary Ann Liebert, Inc. 2011.
Resumo:
Background: The families of people with late-stage dementia need to be informed about the course of the dementia and the comfort/ palliative care option. A booklet was written for that purpose and can be provided to family members by physicians and nurses. Methods: The acceptability of the booklet for nurses was tested in Canada (French and English version), France (French Canadian version) and Japan (translated and adapted version). Results: Overall, 188 nurses completed a survey questionnaire. The booklet was accepted best in Canada and less so in France and Japan. Despite regional variation, the majority of the nurses perceived the booklet as useful for families. The French and Japanese nurses also reported a greater need for palliative care education in advanced dementia. Conclusion: The booklet may help nurses educate families about end-of-life issues in dementia palliative care, but local adaptation of the booklet content and physician engagement are necessary.
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This study aims to explore the potential for palliative care among people living with advanced chronic obstructive pulmonary disease (COPD). Individual semi-structured interviews (n=13) were conducted with people who had a diagnosis of advanced COPD and were on optimal tolerated drug therapy, with their breathing volume (forced expiratory volume at less than 30%) or were on long-term oxygen therapy or non-invasion ventilation. Participants raised concerns about the uncertain trajectory of the illness and reported unmet palliative care needs with poor access to palliative care services. For most people, palliative care was associated with end of life; therefore, they were unwilling to discuss the issue. There was a wide acceptance that, medically, nothing more could be done. Findings also suggest that patients had unmet palliative care needs, requiring information and support. The research suggests the need for palliative care to be extended to all (regardless of diagnosis), with packages of care developed to target specific needs.
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Molecularly Imprinted Polymers (MIPs) against imiquimod, a highly potent immune response modifier used in the treatment of skin cancer, were synthesised using a template analogue strategy and were compared with imprints of the drug itself. An investigation of the complexation between the functional monomer and the template analogue revealed an association constant of 1,376 ± 122 M-1, significantly higher than previously reported values for similar systems. The binding characteristics of the synthesised imprinted polymers were evaluated and extremely strong binding for imiquimod was observed while imprinting factors as high as 17 were calculated. When applied as sorbents in solid-phase extraction of imiquimod from aqueous, urine and blood serum samples, clean extracts and recoveries up to 95% were achieved, and it is concluded that while imiquimod imprints exhibited higher capacity for the drug, template analogue imprints are more selective. The results obtained suggest potential applications of imiquimod imprints as sorbents in rapid extraction and monitoring of undesirable systemic release of the drug.