82 research outputs found
Formation and stability of icosahedral phase in Al65Ga5Pd17Mn13 alloy
In this work, we present the formation and characterization of a quaternary
(pseudo ternary) icosahedral quasicrystal in Al65Ga5Pd17Mn13 alloy. The X ray
diffraction and transmission electron microscopy confirmed the formation of
icosahedral B2 type and O crystalline (orthorhombic structure) phases in as
cast alloy. The icosahedral phase gets formed after annealing at 800 C for 60
hours. The formation of icosahedral phase in AlGaPdMn quaternary alloy by
present technique has been studied for the first time. The Energy dispersive
X-ray analysis investigations suggest the presence of Ga (5 at) in the alloy.
It is interesting to note that pseudo twelve fold pattern in the as cast alloy
has been observed. Icosahedral AlGaPdMn provides a new opportunity to
investigate the various characteristics including surface characteristics.
Attempts will be made to discuss the micromechanisms for the formation of
quasicrystalline phase in Al-Ga-Pd-Mn alloys.Comment: 14 pages 5 figure
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Health-related quality of life in Huntington’s Disease patients: a comparison of proxy assessment and patient self-rating using the disease-specific Huntington’s Disease health-related quality of life questionnaire (HDQoL)
Huntington’s disease (HD) is a fatal, neurodegenerative disease for which there is no known cure. Proxy evaluation is relevant for HD as its manifestation might limit the ability of persons to report their health-related quality of life (HrQoL). This study explored patient–proxy ratings of HrQoL of persons at different stages of HD, and examined factors that may affect proxy ratings. A total of 105 patient–proxy pairs completed the Huntington’s disease health-related quality of life questionnaire (HDQoL) and other established HrQoL measures (EQ-5D and SF-12v2). Proxy–patient agreement was assessed in terms of absolute level (mean ratings) and intraclass correlation. Proxies’ ratings were at a similar level to patients’ self-ratings on an overall Summary Score and on most of the six Specific Scales of the HDQoL. On the Specific Hopes and Worries Scale, proxies on average rated HrQoL as better than patients’ self-ratings, while on both the Specific Cognitive Scale and Specific Physical and Functional Scale proxies tended to rate HrQoL more poorly than patients themselves. The patient’s disease stage and mental wellbeing (SF-12 Mental Component scale) were the two factors that primarily affected proxy assessment. Proxy scores were strongly correlated with patients’ self-ratings of HrQoL, on the Summary Scale and all Specific Scales. The patient–proxy correlation was lower for patients at moderate stages of HD compared to patients at early and advanced stages. The proxy report version of the HDQoL is a useful complementary tool to self-assessment, and a promising alternative when individual patients with advanced HD are unable to self-report
An online network tool for quality information to answer questions about occupational safety and health: usability and applicability
<p>Abstract</p> <p>Background</p> <p>Common information facilities do not always provide the quality information needed to answer questions on health or health-related issues, such as Occupational Safety and Health (OSH) matters. Barriers may be the accessibility, quantity and readability of information. Online Question & Answer (Q&A) network tools, which link questioners directly to experts can overcome some of these barriers. When designing and testing online tools, assessing the usability and applicability is essential. Therefore, the purpose of this study is to assess the usability and applicability of a new online Q&A network tool for answers on OSH questions.</p> <p>Methods</p> <p>We applied a cross-sectional usability test design. Eight occupational health experts and twelve potential questioners from the working population (workers) were purposively selected to include a variety of computer- and internet-experiences. During the test, participants were first observed while executing eight tasks that entailed important features of the tool. In addition, they were interviewed. Through task observations and interviews we assessed applicability, usability (effectiveness, efficiency and satisfaction) and facilitators and barriers in use.</p> <p>Results</p> <p>Most features were usable, though several could be improved. Most tasks were executed effectively. Some tasks, for example searching stored questions in categories, were not executed efficiently and participants were less satisfied with the corresponding features. Participants' recommendations led to improvements. The tool was found mostly applicable for additional information, to observe new OSH trends and to improve contact between OSH experts and workers. Hosting and support by a trustworthy professional organization, effective implementation campaigns, timely answering and anonymity were seen as important use requirements.</p> <p>Conclusions</p> <p>This network tool is a promising new strategy for offering company workers high quality information to answer OSH questions. Q&A network tools can be an addition to existing information facilities in the field of OSH, but also to other healthcare fields struggling with how to answer questions from people in practice with high quality information. In the near future, we will focus on the use of the tool and its effects on information and knowledge dissemination.</p
Relevance of a subjective quality of life questionnaire for long-term homeless persons with schizophrenia
How do healthcare consumers process and evaluate comparative healthcare information? A qualitative study using cognitive interviews
Background: To date, online public healthcare reports have not been effectively used by
consumers. Therefore, we qualitatively examined how healthcare consumers process and evaluate
comparative healthcare information on the Internet.
Methods: Using semi-structured cognitive interviews, interviewees (n = 20) were asked to think
aloud and answer questions, as they were prompted with three Dutch web pages providing
comparative healthcare information.
Results: We identified twelve themes from consumers' thoughts and evaluations. These themes
were categorized under four important areas of interest: (1) a response to the design; (2) a
response to the information content; (3) the use of the information, and (4) the purpose of the
information.
Conclusion: Several barriers to an effective use of comparative healthcare information were
identified, such as too much information and the ambiguity of terms presented on websites.
Particularly important for future research is the question of how comparative healthcare
information can be integrated with alternative information, such as patient reviews on the Internet.
Furthermore, the readability of quality of care concepts is an issue that needs further attention,
both from websites and communication experts.
Relationship of depression, disability, and family caregiver attitudes to the quality of life of Kuwaiti persons with multiple sclerosis: a controlled study
<p>Abstract</p> <p>Background</p> <p>Assessment of subjective quality of life (QOL) of persons with multiple sclerosis (MS) could facilitate the detection of psychosocial aspects of disease that may otherwise go unrecognized. The objectives of the study were to (i) compare the QOL ratings of relapsing remitting (RRMS) and progressive (PMS) types of MS with those of a general population group and the impression of their family caregivers; and (ii) assess the association of demographic, clinical, treatment, depression, and caregiver variables with patients' QOL.</p> <p>Methods</p> <p>Consecutive clinic attendees at the national neurology hospital were assessed with the 26 -item WHOQOL Instrument, Beck's Depression Inventory and Expanded Disability Scale. Caregivers rated their impression of patients' QOL and attitudes to patients' illness.</p> <p>Results</p> <p>The 170 patients (60 m, 109 f) consisted of 145(85.3%) with RRMS and 25 with PMS, aged 32.4(SD 8.8), age at onset 27.1(7.7), EDSS score 2.9 (1.8), and 76% were employed. The patients were predominantly dissatisfied with their life circumstances. The RRMS group had higher QOL domain scores (P < 0.001), and lower depression(P > 0.05) and disability (P < 0.0001) scores than the PMS group. Patients had significantly lower QOL scores than the control group (P < 0.001). Caregiver impression was significantly correlated with patients' ratings. Depression was the commonest significant covariate of QOL domains. When we controlled for depression and disability scores, differences between the two MS groups became significant for only one (out of 6) QOL domains. Patients who were younger, better educated, employed, felt less sick and with lesser side effects, had higher QOL. The predictors of patients' overall QOL were disability score, caregiver impression of patients' QOL, and caregiver fear of having MS.</p> <p>Conclusion</p> <p>Our data indicate that MS patients in stable condition and with social support can hope to have better QOL, if clinicians pay attention to depression, disability, the impact of side effects of treatment and family caregiver anxieties about the illness. The findings call for a regular program of psychosocial intervention in the clinical setting, to address these issues and provide caregiver education and supports, in order to enhance the quality of care.</p
Factors associated with quality of life of outpatients with breast cancer and gynecologic cancers and their family caregivers: a controlled study
<p>Abstract</p> <p>Background</p> <p>Quality of life (QOL) issues are of interest in cancer because effective methods of treatment and detection have led to an increase in the number of long-term survivors. The objectives of the study were: to assess the subjective QOL of stable Sudanese women cancer outpatients and their family caregivers, using the WHO 26-item QOL Instrument; compare with matched general population groups, as well as diabetic and psychiatric patient groups; examine patient-caregiver concordance in ratings; and assess the variables associated with their QOL, with a view to identifying factors that can enhance quality of care.</p> <p>Methods</p> <p>Responses of oncology outpatients with breast cancer (117), cervical cancer (46) and ovarian cancer (18) (aged 44.6, SD 11.5) were compared with those of their family caregivers and matched general population groups. Data were analyzed by univariate and multivariate statistics.</p> <p>Results</p> <p>The cancer groups had similar QOL domain scores, which were significantly lower than those of their caregivers, but higher than the control group as well as those of psychiatric and diabetic patients studied previously. Patients who were married, with higher education, better employment, and with longer duration of illness had higher QOL. Patients on radiotherapy and their caregivers had higher QOL scores. Correlations between patient's ratings and caregiver impression of patient's QOL were high. Caregiver impression was a significant predictor of patient's and caregiver's QOL. Other predictors for the patient were: currently feeling sick and duration of illness; for the caregiver: feeling sick, relationship to patient, and age.</p> <p>Conclusion</p> <p>Cancer patients in stable condition and with psychosocial support can hope to enjoy good QOL with treatment. The findings constitute an evidence base for the country's cancer care program, to boost national health education about prognosis in cancer. Families living with women cancer patients are vulnerable and need support if the patient is recently diagnosed, less educated, single, not formally employed; and the caregiver is female, parent, younger, less educated, unemployed and feels sick. Clinicians need to invest in the education and support of family caregivers. The patient-caregiver dyad should be regarded as a unit for treatment in cancer care.</p
THE T2 COMPOUND : A STABLE QUASI-CRYSTAL IN THE SYSTEM Al-Li-Cu-(Mg) ?
Le système Al-Cu-Li présente deux composés intermétalliques stables, de compositions très proches, remarquables par leur cristallographie. La phase cubique Al5CuLi3 possède des arrangements atomiques en icosaèdres et triacontaèdres. La phase Al6CuLi3 donne des spectres de diffraction X et des diagrammes de diffraction électronique caractéristiques de la structure quasi-cristalline. Cette phase est obtenue par solidification conventionnelle sous forme de mono quasi-cristaux de plusieurs millimètres de long. Elle peut également être précipitée de manière réversible par traitement thermique de solutions solides homogènes d'alliages d'aluminium saturés en cuivre et lithium.Two stable phases of the Al-Li-Cu system exhibit interesting crystallographic features. The R-Al5CuLi3 compound has a Im3 point group with icosahedral and triacontahedral arrangements. The Al6CuLi3 compound has a quasi-crystalline like structure as confirmed by both X-ray and electron diffraction. This phase may be obtained either as large single quasi-crystals by conventional casting or as reversible precipitation by ageing of aluminium rich solid solutions
COPRECIPITATION HARDENING IN Al-Li-Cu-Mg ALLOYS
The structural features of the matrix precipitates families governing the strength of Al-Li-Cu-Mg(-Zr) alloys within a wide composition range are discussed. The specific effects of alloying and heat treating on matrix coprecipitation of δ', GPB zones, S', S, T' or θ', T1, and T2 and the dependence of the solid solution decomposition sequence on cold working between quenching and ageing are illustrated by transmission electron microscopy results. Conventional artificial ageing treatments and selective reversion heat treatments, performed on both laboratory and commercial alloys, allow to evaluate the intrinsic contributions of matrix precipitates on complex coprecipitation hardening in industrial alloys
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