2,895 research outputs found

    Mistake

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    A sinc function analogue of chebfun

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    Chebfun is an established software system for computing with functions of a real variable, but its capabilities for handling functions with singularities are limited. Here an analogous system is described based on sinc function expansions instead of Chebyshev series. This experiment sheds light on the strengths and weaknesses of sinc function techniques. It also serves as a review of some of the main features of sinc methods including construction, evaluation, zero�finding, optimization, integration and di�fferentiation

    A Sinc Function Analogue of Chebfun

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    Relationships of Clinical, Psychologic, and Individual Factors with the Functional Status of Neck Pain Patients

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    AbstractObjectiveThe objective of this study was to use both generic and disease-specific functional measures examining relationships of clinical, psychologic, and individual factors with the functional status of neck pain patients.MethodsPatients who visited a university-based spine clinic and reported neck pain were included in this study. A comprehensive computerized survey questionnaire was used to collect the information related to this study. The questionnaire also contained a generic measure, short form 12-item survey (SF-12), and a disease-specific measure, neck disability index (NDI). Correlation and multiple regression analysis were conducted to examine the relationships.ResultsA range of clinical, psychologic, and individual factors emerged to be significant predictors of the NDI or physical component of the SF-12 (PCS). The predictors of higher NDI included higher levels of neck pain, higher levels of back pain, higher levels of pain in arm or shoulder areas, not working, lower education, higher stress, the presence of depression or anxiety, and smoking. The predictors of lower PCS included not working, higher levels of back pain, higher levels of neck pain, lower education, female sex, the presence of cardiovascular disorders, the absence of cervical disk disorders, and older age.Conclusions The  predictors  of  the  NDI  or  PCS  appear to be multidimensional. Interventions designed to maximally improve the functional status of neck pain patients should be multifaceted and involve multidisciplinary teams. Selection of the most appropriate functional measures for an intervention study should consider differences between the generic and disease-specific measures in terms of their respective relationships with targeted factors. Prospective studies are needed to confirm the relationships observed in this study

    Hydrazone chelators for the treatment of iron overload disorders: iron coordination chemistry and biological activity

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    The potentially tridentate ligand 2-pyridinecarbaldehyde isonicotinoyl hydrazone (HPCIH) and its analogues are an emerging class of orally effective Fe chelators that show great promise for the treatment of Fe overload diseases. Herein, we present an extensive study of the Fe coordination chemistry of the HPCIH analogues including the first crystallographically characterised Fe-II complex of these chelators. Unlike most other clinically effective Fe chelators, the HPCIH analogues bind Fe-II and not F-III. In fact, these chelators form low-spin bis-ligand F-II complexes, although NMR suggests that the complexes are close to the high-spin/low-spin crossover. All the Fe complexes show a high potential Fe-III/(II) redox couple (> 500 mV vs. NHE) and cyclic voltammetry in aqueous or mixed aqueous/organic solvents is irreversible as a consequence of a rapid hydration reaction that occurs upon oxidation. A number of the HPCIH analogues show high activity at inducing Fe efflux from cells and also at preventing Fe uptake by cells from the serum Fe transport protein transferrin. As a class of ligands, these chelators are more effective at reducing Fe uptake from transferrin than inducing Fe mobilisation from cells. This may be related to their ability to intercept Fe-II after its release from transferrin within the cell. Our studies indicate that their Fe chelation efficacy is due, at least in part, to the fact that these ligands and their Fe-II complexes are neutral at physiological pH (7.4) and sufficiently lipophilic to permeate cell membranes

    Long Wave Ultrasonic Characterization of Inclusions in Silicon Nitride

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    The size and material content of Fe and Si inclusions in Si3N4 have been measured by means of pulse-echo scattering of elastic waves in the frequency range 5 to 100 MHz. The inclusions were of 100 μm and 400 μm nominal diameters and were located 3 mm deep in the Si3N4. The electronic noise was reduced by signal averaging and, in some cases, the noise due to grain scattering was reduced by averaging over transducer position. The scattering amplitude A(ω) and the impulse function R(t) were obtained by a desensitized deconvolution of the reference waveform obtained by reflecting the transmitted pulse from the back surface of the sample in a defect-free region. Comparison of theory and experiment are given for A(ω) and estimates of flaw size and material content are presented

    "Until the trial is complete you can't really say whether it helped you or not, can you?": exploring cancer patients' perceptions of taking part in a trial of acupressure wristbands.

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    BACKGROUND: Nested qualitative studies within clinical trials provide data on patients' experiences of receiving trial interventions and can inform and improve trial designs. The present study explored patients' experiences of participating in a randomised controlled trial of acupressure wristbands for chemotherapy related nausea. METHODS: A randomised three-group sham-controlled trial was carried out to evaluate the effectiveness of acupressure wristbands in the management of chemotherapy-related nausea. A convenience sample of 26 patients volunteered to participate in a qualitative study to explore their experiences of using acupressure wristbands, and taking part in the clinical trial. Participants were recruited from each of the three UK geographical sites from which the trial was conducted: Manchester, Liverpool and Plymouth. In-depth semi-structured interviews were conducted with the participants in their own homes or other location convenient for participating patients. Interviews were audio-taped, transcribed verbatim and analysed using Framework methodology. RESULTS: The main motivational factors influencing participants to take part in the trial were a desire to 'give something back' and limit their own experience of nausea. Participants were largely satisfied with the organisation and running of the acupressure wristband trial. Many participants experienced positive outcomes as a result of taking part in the trial. Lapses in memory, or poor health as a result of their chemotherapy treatment, led to some participants failing to complete trial paperwork on designated days. Two sham wristband participants reported wearing the bands inappropriately resulting in pressure being applied to the acupoint. Almost all of the participants interviewed had only experienced mild nausea or vomiting during the trial. Participants were pragmatic on the extent to which the wristbands were responsible for this lack of nausea and vomiting during the trial. However, many participants, including some patients receiving sham acupressure, believed the wristbands to have had a positive impact on their nausea and vomiting; there was a perception that the wristbands were, at least in part, responsible for the lack of nausea and vomiting they had experienced. CONCLUSIONS: Participants perceive acupressure wristbands as reducing the level of nausea and vomiting experienced during chemotherapy treatment. Reports that some participants wore wristbands inappropriately, and/or delayed completion of trial paperwork could represent confounding variables and have implications for the trial results, and the design of clinical trials within the field of cancer

    Critical review of the determinants of medication adherence in patients with dementia

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    © 2020 The Authors. Published by Innovare Academic Sciences. This is an open access article available under a Creative Commons licence. The published version can be accessed at the following link on the publisher’s website: https://doi.org/10.22159/ijcpr.2020v12i3.38325Objective: Medication adherence is a prominent issue in the general population; therefore, due to the nature of dementia, the risk of medication no adherence is even greater. Furthermore, there have been discrepancies regarding the impact of specific determinants on medication adherence as previous literature has cited conflicting information. This review aimed to identify the potential causative relationship of dementia that may result in medication non-adherence.
 Methods: A meta-analysis of (15 primary research papers) was conducted to identify and assess the specific themes and determinants related to non-adherence, and their impact on medication adherence in those who were cognitively impaired.
 Results: Four domains were established or developed upon review and risk of bias and risk of the summary table were created. A critical review undertaken to analyse various papers and their respective findings. Through the data analysis it was found that common themes could be established, such as Cognitive impairment, Disability, Mental illness and occasional forgetfulness to take their medication. The impact of each domain was expressed e. g. the predominant role of executive function and memory as well as non-adherence leading to delusional or suspicious thoughts.
 Conclusion: The findings align with current literature. The caregiver aspect needs to be addressed more thoroughly and more investigations are required such as identifying underlying factors that may potentially result in influence.Published onlin

    Analysis of clinical uncertainties by health professionals and patients: an example from mental health

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    <p>Abstract</p> <p>Background</p> <p>The first step in practising Evidence Based Medicine (EBM) has been described as translating clinical uncertainty into a structured and focused clinical question that can be used to search the literature to ascertain or refute that uncertainty. In this study we focus on questions about treatments for schizophrenia posed by mental health professionals and patients to gain a deeper understanding about types of questions asked naturally, and whether they can be reformulated into structured and focused clinical questions.</p> <p>Methods</p> <p>From a survey of uncertainties about the treatment of schizophrenia we describe, categorise and analyse the type of questions asked by mental health professionals and patients about treatment uncertainties for schizophrenia. We explore the value of mapping from an unstructured to a structured framework, test inter-rater reliability for this task, develop a linguistic taxonomy, and cross tabulate that taxonomy with elements of a well structured clinical question.</p> <p>Results</p> <p>Few of the 78 Patients and 161 clinicians spontaneously asked well structured queries about treatment uncertainties for schizophrenia. Uncertainties were most commonly about drug treatments (45.3% of clinicians and 41% of patients), psychological therapies (19.9% of clinicians and 9% of patients) or were unclassifiable.(11.8% of clinicians and 16.7% of patients). Few naturally asked questions could be classified using the well structured and focused clinical question format (i.e. PICO format). A simple linguistic taxonomy better described the types of questions people naturally ask.</p> <p>Conclusion</p> <p>People do not spontaneously ask well structured clinical questions. Other taxonomies may better capture the nature of questions. However, access to EBM resources is greatly facilitated by framing enquiries in the language of EBM, such as posing queries in PICO format. People do not naturally do this. It may be preferable to identify a way of searching the literature that more closely matches the way people naturally ask questions if access to information about treatments are to be made more broadly available.</p
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