23 research outputs found

    Determination of Magnetic Exchange Stiffness and Surface Anisotropy Constants in Epitaxial Ni_ {1-x} Co_ {x}(001) Films

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    Magnetic characteristics of epitaxial Ni1-xCox(001) (x=0, 0.16, and 0.50) films with nominal 200 nm thickness on Cu(001)/Si(100) substrates have been investigated by magnetization and ferromagnetic resonance measurements in order to better clarify the rationale for the large variation in the magnetic exchange stiffness constant A, previously determined from different measurements. The exchange constant as well as the saturation magnetization, effective demagnetizing field, fourth-order magnetocrystalline, and second-order perpendicular uniaxial magnetic anisotropy fields has been determined. The analyses of low-temperature saturation magnetization data on these films yield A values that increase from 0.82×10-6erg/cm for a pure Ni film to 2.27×10-6erg/cm for the Ni0.50Co0.50 film. Furthermore, spin-wave resonance volume modes observed in x=0 and 0.16 films indicate that the surface plays a role in the exchange stiffness constant determination as the surface anisotropy constants are found to be approximately 1 and 4 erg/cm2, respectively. The latter value is substantially larger than that for any other system reported so far

    X-Linked thrombocytopenia causing mutations in WASP (L46P and A47D) impair T cell chemotaxis

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    BACKGROUND: Mutation in the Wiskott-Aldrich syndrome Protein (WASP) causes Wiskott-Aldrich syndrome (WAS), X-linked thrombocytopenia (XLT) and X-linked congenital neutropenia (XLN). The majority of missense mutations causing WAS and XLT are found in the WH1 (WASP Homology) domain of WASP, known to mediate interaction with WIP (WASP Interacting Protein) and CIB1 (Calcium and Integrin Binding). RESULTS: We analyzed two WASP missense mutants (L46P and A47D) causing XLT for their effects on T cell chemotaxis. Both mutants, WASP(R)(L46P) and WASP(R)(A47D) (S1-WASP shRNA resistant) expressed well in Jurkat(WASP-KD) T cells (WASP knockdown), however expression of these two mutants did not rescue the chemotaxis defect of Jurkat(WASP-KD) T cells towards SDF-1α. In addition Jurkat(WASP-KD) T cells expressing these two WASP mutants were found to be defective in T cell polarization when stimulated with SDF-1α. WASP exists in a closed conformation in the presence of WIP, however both the mutants (WASP(R)(L46P) and WASP(R)(A47D)) were found to be in an open conformation as determined in the bi-molecular complementation assay. WASP protein undergoes proteolysis upon phosphorylation and this turnover of WASP is critical for T cell migration. Both the WASP mutants were found to be stable and have reduced tyrosine phosphorylation after stimulation with SDF-1α. CONCLUSION: Thus our data suggest that missense mutations WASP(R)(L46P) or WASP(R)(A47D) affect the activity of WASP in T cell chemotaxis probably by affecting the turnover of the protein. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12929-014-0091-1) contains supplementary material, which is available to authorized users

    Shared decision making and experiences of patients with long-term conditions : has anything changed?

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    Background Medication problems among patients with long-term conditions (LTCs) are well documented. Measures to support LTC management include: medicine optimisation services by community pharmacists such as the Medicine Use Review (MUR) service in England, implementation of shared decision making (SDM), and the availability of rapid access clinics in primary care. This study aimed to investigate the experience of patients with LTCs about SDM including medication counselling and their awareness of community pharmacy medication review services. Methods A mixed research method with a purposive sampling strategy to recruit patients was used. The quantitative phase involved two surveys, each requiring a sample size of 319. The first was related to SDM experience and the second to medication counselling at discharge. Patients were recruited from medical wards at St. George’s and Croydon University Hospitals.The qualitative phase involved semi-structured interviews with 18 respiratory patients attending a community rapid access clinic. Interviews were audio-recorded and transcribed verbatim. Thematic analysis using inductive/deductive approaches was employed. Survey results were analysed using descriptive statistics. Results The response rate for surveys 1 and 2 survey was 79% (n = 357/450) and 68.5% (240/350) respectively. Survey 1 showed that although 70% of patients had changes made to their medications, only 40% were consulted about them and two-thirds (62.2%) wanted to be involved in SDM. In survey 2, 37.5% of patients thought that medication counselling could be improved. Most patients (88.8%) were interested in receiving the MUR service; however 83% were not aware of it. The majority (57.9%) were interested in receiving their discharge medications from community pharmacies. The interviews generated three themes; lack of patient-centered care and SDM, minimal medication counselling provided and lack of awareness about the MUR service. Conclusion Although patients wanted to take part in SDM, yet SDM and medication counselling are not optimally provided. Patients were interested in the MUR service; however there was lack of awareness and referral for this service. The results propose community pharmacy as a new care pathway for medication supply and counselling post discharge. This promotes a change of health policy whereby community-based services are used to enhance the performance of acute hospitals

    Baseline characteristics of patients in the reduction of events with darbepoetin alfa in heart failure trial (RED-HF)

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    <p>Aims: This report describes the baseline characteristics of patients in the Reduction of Events with Darbepoetin alfa in Heart Failure trial (RED-HF) which is testing the hypothesis that anaemia correction with darbepoetin alfa will reduce the composite endpoint of death from any cause or hospital admission for worsening heart failure, and improve other outcomes.</p> <p>Methods and results: Key demographic, clinical, and laboratory findings, along with baseline treatment, are reported and compared with those of patients in other recent clinical trials in heart failure. Compared with other recent trials, RED-HF enrolled more elderly [mean age 70 (SD 11.4) years], female (41%), and black (9%) patients. RED-HF patients more often had diabetes (46%) and renal impairment (72% had an estimated glomerular filtration rate <60 mL/min/1.73 m2). Patients in RED-HF had heart failure of longer duration [5.3 (5.4) years], worse NYHA class (35% II, 63% III, and 2% IV), and more signs of congestion. Mean EF was 30% (6.8%). RED-HF patients were well treated at randomization, and pharmacological therapy at baseline was broadly similar to that of other recent trials, taking account of study-specific inclusion/exclusion criteria. Median (interquartile range) haemoglobin at baseline was 112 (106–117) g/L.</p> <p>Conclusion: The anaemic patients enrolled in RED-HF were older, moderately to markedly symptomatic, and had extensive co-morbidity.</p&gt
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