349 research outputs found

    Acute care nurses' perceptions of barriers to using research information in clinical decision-making

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    Aim. To examine the barriers that nurses feel prevent them from using research in the decisions they make. Background. A sizeable research literature focusing on research utilization in nursing has developed over the past 20 years. However, this literature is characterized by a number of weaknesses: self-reported utilization behaviour; poor response rates and small, nonrandom sampling strategies. Design. Cross-case analysis involving anonymised qualitative interviews, observation, documentary audit and Q methodological modelling of shared subjectivities amongst nurses. The case sites were three large acute hospitals in the north of England. One hundred and eight nurses were interviewed, 61 of whom were also observed for a total of 180 h, and 122 nurses were involved in the Q modelling exercise (response rate of 64%). Results. Four perspectives were isolated that encompassed the characteristics associated with barriers to research use. These related to the individual, organization, nature of research information itself and environment. Nurses clustered around four main perspectives on the barriers to research use: (1) Problems in interpreting and using research products, which were seen as too complex, 'academic' and overly statistical; (2) Nurses who felt confident with research-based information perceived a lack of organizational support as a significant block; (3) Many nurses felt that researchers and research products lack clinical credibility and that they fail to offer the desired level of clinical direction; (4) Some nurses lacked the skills and, to a lesser degree, the motivation to use research themselves. These individuals liked research messages passed on to them by a third party and sought to foster others' involvement in research-based practice, rather than becoming directly involved themselves. Conclusions. Rejection of research knowledge is not a barrier to its application. Rather, the presentation and management of research knowledge in the workplace represent significant challenges for clinicians, policy-makers and the research community

    The accessibility of research-based knowledge for nurses in United Kingdom acute care settings

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    Background. The successful dissemination of the results of the National Health Service (NHS) research and development strategy and the development of evidence based approaches to health care rely on clinicians having access to the best available evidence; evidence fit for the purpose of reducing the uncertainties associated with clinical decisions. Aim. To reveal the accessibility of those sources of information actually used by nurses, as well as those which they say they use. Design. Mixed method case site, using interview, observational, Q sort and documentary audit data in medical, surgical and coronary care units (CCUs) in three acute hospitals. Results. Three perspectives on accessibility were identified: (a) the humanist-in which human sources of information were the most accessible; (b) local information for local needs-in which locally produced resources were seen as the most accessible and (c) moving towards technology-in which information technology begins to be seen as accessible. Nurses' experience in a clinical specialty is positively associated with a perception that human sources such clinical nurse specialists, link nurses, doctors and experienced clinical colleagues are more accessible than text based sources. Clinical specialization is associated with different approaches to accessing research knowledge. Coronary care unit nurses were more likely perceive local guidelines, protocols and on-line databases as more accessible than their counterparts in general medical and surgical wards. Only a third of text-based resources available to nurses oil the wards had any explicit research base. These, and the remainder were Out of date (mean age of textbooks 11 years), and authorship hard to ascertain. Conclusion. A strategy to increase the use of research evidence by nurses should harness the influence of clinical nurse specialists, link nurses and those engaged in practice development. These roles Could act as 'conduits' through which research-based messages for practice, and information for clinical decision making, could flow. This role should be explored and enhanced

    Interaction effects and quantum phase transitions in topological insulators

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    We study strong correlation effects in topological insulators via the Lanczos algorithm, which we utilize to calculate the exact many-particle ground-state wave function and its topological properties. We analyze the simple, noninteracting Haldane model on a honeycomb lattice with known topological properties and demonstrate that these properties are already evident in small clusters. Next, we consider interacting fermions by introducing repulsive nearest-neighbor interactions. A first-order quantum phase transition was discovered at finite interaction strength between the topological band insulator and a topologically trivial Mott insulating phase by use of the fidelity metric and the charge-density-wave structure factor. We construct the phase diagram at T=0T = 0 as a function of the interaction strength and the complex phase for the next-nearest-neighbor hoppings. Finally, we consider the Haldane model with interacting hard-core bosons, where no evidence for a topological phase is observed. An important general conclusion of our work is that despite the intrinsic nonlocality of topological phases their key topological properties manifest themselves already in small systems and therefore can be studied numerically via exact diagonalization and observed experimentally, e.g., with trapped ions and cold atoms in optical lattices.Comment: 13 pages, 12 figures. Published versio

    Accurate evaluation of the Green's function of disordered graphenes

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    An accurate simulation of Green's function and self-energy function of non-interacting electrons in disordered graphenes are performed. Fundamental physical quantities such as the elastic relaxation time {\tau}e, the phase velocity vp, and the group velocity vg are evaluated. New features around the Dirac point are revealed, showing hints that multi-scattering induced hybridization of Bloch states plays an important role in the vicinity of the Dirac point.Comment: 4 figure

    Nonperturbative Scaling Theory of Free Magnetic Moment Phases in Disordered Metals

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    The crossover between a free magnetic moment phase and a Kondo phase in low dimensional disordered metals with dilute magnetic impurities is studied. We perform a finite size scaling analysis of the distribution of the Kondo temperature as obtained from a numerical renormalization group calculation of the local magnetic susceptibility and from the solution of the self-consistent Nagaoka-Suhl equation. We find a sizable fraction of free (unscreened) magnetic moments when the exchange coupling falls below a disorder-dependent critical value JcJ_{\rm c}. Our numerical results show that between the free moment phase due to Anderson localization and the Kondo screened phase there is a phase where free moments occur due to the appearance of random local pseudogaps at the Fermi energy whose width and power scale with the elastic scattering rate 1/Ï„1/\tau.Comment: 4 pages, 6 figure

    Growth Mechanism of Nanowires: Ternary Chalcogenides

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    In the past two decades there has been a large rise in the investment and expectations for nanotechnology use. Almost every area of research has projected improvements in sensors, or even a promise for the emergence of some novel device technologies. For these applications major focuses of research are in the areas of nanoparticles and graphene. Although there are some near term applications with nanowires in photodetectors and other low light detectors, there are few papers on the growth mechanism and fabrication of nanowire-based devices. Semiconductor nanowires exhibit very favorable and promising optical properties, including high transparency and a several order of magnitude better photocurrent than thin film and bulk materials. We present here an overview of the mechanism of nanowire growth from the melt, and some preliminary results for the thallium arsenic selenide material system. Thallium arsenic selenide (TAS) is a multifunctional material combining excellent acousto-optical, nonlinear and radiation detection properties. We observed that small units of (TAS) nanocubes arrange and rearrange at moderate melt undercooling to form the building block of a nanowire. In some cases very long wires (less than mm) are formed. Since we avoided the catalyst, we observed self-nucleation and uncontrolled growth of wires from different places

    Growth Mechanism of Nanowires: Binary and Ternary Chalcogenides

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    Semiconductor nanowires exhibit very exciting optical and electrical properties including high transparency and a several order of magnitude better photocurrent than thin film and bulk materials. We present here the mechanism of nanowire growth from the melt-liquid-vapor medium. We describe preliminary results of binary and ternary selenide materials in light of recent theories. Experiments were performed with lead selenide and thallium arsenic selenide systems which are multifunctional material and have been used for detectors, acousto-optical, nonlinear and radiation detection applications. We observed that small units of nanocubes and elongated nanoparticles arrange and rearrange at moderate melt undercooling to form the building block of a nanowire. Since we avoided the catalyst, we observed self-nucleation and uncontrolled growth of wires from different places. Growth of lead selenide nanowires was performed by physical vapor transport method and thallium arsenic selenide nanowire by vapor-liquid-solid (VLS) method. In some cases very long wires (>mm) are formed. To achieve this goal experiments were performed to create situation where nanowires grew on the surface of solid thallium arsenic selenide itself

    Wounds research for patient benefit: a 5-year programme of research

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    Background Complex wounds are those that heal by secondary intention and include lower-limb ulcers, pressure ulcers and some surgical wounds. The care of people with complex wounds is costly, with care mainly being delivered by community nurses. There is a lack of current, high-quality data regarding the numbers and types of people affected, care received and outcomes achieved. Objectives To (1) assess how high-quality data about complex wounds can be captured effectively for use in both service planning and research while ensuring integration with current clinical data collection systems and minimal impact on staff time; (2) investigate whether or not a clinical register of people with complex wounds could give valid estimates of treatment effects, thus reducing dependence on large-scale randomised controlled trials (RCTs); (3) identify the most important research questions and outcomes for people with complex wounds from the perspectives of patients, carers and health-care professionals; (4) evaluate the potential contributions to decision-making of individual patient data meta-analysis and mixed treatment comparison meta-analysis; and (5) complete and update systematic reviews in topic areas of high priority. Methods To meet objectives 1 and 2 we conducted a prevalence survey and developed and piloted a longitudinal disease register. A consultative, deliberative method and in-depth interviews were undertaken to address objective 3. To address objectives 4 and 5 we conducted systematic reviews including mixed treatment comparison meta-analysis. Results From the prevalence survey we estimated the point prevalence of all complex wounds to be 1.47 per 1000 people (95% confidence interval 1.38 to 1.56 per 1000 people). Pressure ulcers and venous leg ulcers were the most common type of complex wound. A total of 195 people with a complex wound were recruited to a complex wounds register pilot. We established the feasibility of correctly identifying, extracting and transferring routine NHS data into the register; however, participant recruitment, data collection and tracking individual wounds in people with multiple wounds were challenging. Most patients and health professionals regarded healing of the wound as the primary treatment goal. Patients were greatly troubled by the social consequences of having a complex wound. Complex wounds are frequently a consequence of, and are themselves, a long-term condition but treatment is usually focused on healing the wound. Consultative, deliberative research agenda setting on pressure ulcer prevention and treatment with patients, carers and clinicians yielded 960 treatment uncertainties and a top 12 list of research priorities. Of 167 RCTs of complex wound treatments in a systematic review of study quality, 41% did not specify a primary outcome and the overall quality of the conduct and reporting of the research was poor. Mixed-treatment comparison meta-analysis in areas of high priority identified that matrix hydrocolloid dressings had the highest probability (70%) of being the most effective dressing for diabetic foot ulcers, whereas a hyaluronan fleece dressing had the highest probability (35%) of being the most effective dressing for venous ulcers; however, the quality of this evidence was low and uncertainty is high. Conclusions Complex wounds are common and costly with a poor evidence base for many frequent clinical decisions. There is little routine clinical data collection in community nursing. A prospective complex wounds register has the potential to both assist clinical decision-making and provide important research evidence but would be challenging to implement without investment in information technology in NHS community services. Future work should focus on developing insights into typical wound healing trajectories, identifying factors that are prognostic for healing and assessing the cost-effectiveness of selected wound treatments. Funding The National Institute for Health Research Programme Grants for Applied Research programme

    Compression hosiery to avoid post-thrombotic syndrome (CHAPS) protocol for a randomised controlled trial (ISRCTN73041168).

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    INTRODUCTION: Up to 50% of patients develop post-thrombotic syndrome (PTS) after an above knee deep vein thrombosis (DVT). The aim of the study was to determine the effect of graduated compression stockings in preventing PTS after DVT. METHODS AND ANALYSIS: Pragmatic, UK multicentre randomised trial in adults with first above knee DVT. The standard of care arm is anticoagulation. The intervention arm will receive anticoagulation plus stockings (European class II, 23-32 mm Hg compression) worn for a median of 18 months. The primary endpoint is PTS using the Villalta score. Analysis of this will be through a time to event approach and cumulative incidence at median 6, 12 and 18 months. An ongoing process evaluation will examine factors contributing to adherence to stockings to understand if and how the behavioural interventions were effective. ETHICS AND DISSEMINATION: UK research ethics committee approval (reference 19/LO/1585). Dissemination though the charity Thrombosis UK, the Imperial College London website, peer-reviewed publications and international conferences. TRIAL REGISTRATION NUMBER: ISRCTN registration number 73041168

    Surface Modification at Nanoscale; Nanoparticle-Nanowire Transition

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    Binary, ternary and quaternary oxides and selenides have been developed and used in multiple applications including high power lasers, detectors, dielectric energy storage and variety of optical devices. These materials have been grown by Bridgman, physical vapor transport (PVT), chemical vapor transport (CVT) methods and flux methods in the form of bulk thin film, nanocrystals and nanowires. With increasing thrust of bio applications, nanoparticles it is essential to understand nucleation and nanomorphological transition during drug delivery, growth of nanoengineered bio composites in body, grain growth and final morphology. Addition of fluorides and selenides have increased significantly in synthetic tissue constituents because of some advantages in adhesion and stability. We have performed experiments on multinary oxides Sr-Ba-O-F, Se-Tl-As and Se-Pb-Sn-Se using several growth methods to demonstrate nanoparticle and nanowire transition. This study has great potential to increase surface area and also provides understanding to the mechanism of nanowire growth
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