113 research outputs found

    Controlling the Frequency-Temperature Sensitivity of a Cryogenic Sapphire Maser Frequency Standard by Manipulating Fe3+ Spins in the Sapphire Lattice

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    To create a stable signal from a cryogenic sapphire maser frequency standard, the frequency-temperature dependence of the supporting Whispering Gallery mode must be annulled. We report the ability to control this dependence by manipulating the paramagnetic susceptibility of Fe3+ ions in the sapphire lattice. We show that the maser signal depends on other Whispering Gallery modes tuned to the pump signal near 31 GHz, and the annulment point can be controlled to exist between 5 to 10 K depending on the Fe3+ ion concentration and the frequency of the pump. This level of control has not been achieved previously, and will allow improvements in the stability of such devices.Comment: 17 pages, 10 figure

    Expansion of CD16-Negative Natural Killer Cells in the Peripheral Blood of Patients with Metastatic Melanoma

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    Altered natural killer (NK) cell function is a component of the global immune dysregulation that occurs in advanced malignancies. Another condition associated with altered NK homeostasis is normal pregnancy, where robust infiltration with CD16− CD9+ NK cells can be identified in decidual tissues, along with a concomitant expansion of CD16− NK cells in the maternal peripheral blood. In metastatic melanoma, we identified a similar expansion of peripheral blood CD16− NK cells (median 7.4% in 41 patients with melanoma compared with 3.0% in 29 controls, P < .001). A subset of NK cells in melanoma patients also expresses CD9, which is characteristically expressed only on NK cells within the female reproductive tract. Expansion of CD16− NK cells was associated with elevated plasma transforming growth factor-beta (TGF-β levels (median 20 ng/ml, Spearman's ρ = 0.81, P = .015)). These findings suggest the possibility of exploring anti-TGF-β therapy to restore NK function in melanoma

    Nurse prescribing of medicines in Western European and Anglo-Saxon countries: a systematic review of the literature

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    <p>Abstract</p> <p>Background</p> <p>A growing number of countries are introducing some form of nurse prescribing. However, international reviews concerning nurse prescribing are scarce and lack a systematic and theoretical approach. The aim of this review was twofold: firstly, to gain insight into the scientific and professional literature describing the extent to and the ways in which nurse prescribing has been realised or is being introduced in Western European and Anglo-Saxon countries; secondly, to identify possible mechanisms underlying the introduction and organisation of nurse prescribing on the basis of Abbott's theory on the division of professional labor.</p> <p>Methods</p> <p>A comprehensive search of six literature databases and seven websites was performed without any limitation as to date of publication, language or country. Additionally, experts in the field of nurse prescribing were consulted. A three stage inclusion process, consisting of initial sifting, more detailed selection and checking full-text publications, was performed independently by pairs of reviewers. Data were synthesized using narrative and tabular methods.</p> <p>Results</p> <p>One hundred and twenty-four publications met the inclusion criteria. So far, seven Western European and Anglo-Saxon countries have implemented nurse prescribing of medicines, viz., Australia, Canada, Ireland, New Zealand, Sweden, the UK and the USA. The Netherlands and Spain are in the process of introducing nurse prescribing. A diversity of external and internal forces has led to the introduction of nurse prescribing internationally. The legal, educational and organizational conditions under which nurses prescribe medicines vary considerably between countries; from situations where nurses prescribe independently to situations in which prescribing by nurses is only allowed under strict conditions and supervision of physicians.</p> <p>Conclusions</p> <p>Differences between countries are reflected in the jurisdictional settlements between the nursing and medical professions concerning prescribing. In some countries, nurses share (full) jurisdiction with the medical profession, whereas in other countries nurses prescribe in a subordinate position. In most countries the jurisdiction over prescribing remains predominantly with the medical profession. There seems to be a mechanism linking the jurisdictional settlements between professions with the forces that led to the introduction of nurse prescribing. Forces focussing on efficiency appear to lead to more extensive prescribing rights.</p

    Characterising the growth in palliative care prescribing 2011-2015: Analysis of national medical and non-medical activity

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    YesThe role of non-medical prescribers working in palliative care has been expanding in recent years and prescribers report improvements in patient care, patient safety, better use of health professionals’ skills and more flexible team working. Despite this, there is a lack of empirical evidence to demonstrate its clinical and economic impact, limiting our understanding of the future role of non-medical prescribers within a healthcare system serving an increasing number of people with palliative care needs. We developed a unique methodology to establish the level of non-medical prescribers’ activity in palliative care across England and consider the likely overall contribution these prescribers are making at a national level in this context in relation to medical prescribing. All prescriptions for 10 core palliative care drugs prescribed by general practitioners, nurses and pharmacists in England and dispensed in the community between April 2011 and April 2015 were extracted from the Prescribing Analysis Cost Tool system. The data were broken down by prescriber and basic descriptive analysis of prescription frequencies by opioid, non-opioids and total prescriptions by year were undertaken. To evaluate the yearly growth of non-medical prescribers, the total number of prescriptions was compared by year for each prescribing group. Non-medical prescribers issued prescriptions rose by 28% per year compared to 9% in those issued by medical prescribers. Despite this, the annual growth in non-medical prescribers prescriptions was less than 1% a year in relation to total community palliative care prescribing activity in England. Impact on medical prescribing is therefore minimal

    Porous ferroelectrics for energy harvesting applications

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    This paper provides an overview of energy harvesting using ferroelectric materials, with a particular focus on the energy harvesting capabilities of porous ferroelectric ceramics for both piezo- and pyroelectric harvesting. The benefits of introducing porosity into ferro- electrics such as lead zirconate titanate (PZT) has been known for over 30 years, but the potential advantages for energy harvesting from both ambient vibrations and temperature fluctuations have not been studied in depth. The article briefly discusses piezoelectric and pyro- electric energy harvesting, before evaluating the potential benefits of porous materials for increasing energy harvesting figures of merits and electromechanical/electrothermal coupling factors. Established processing routes are evaluated in terms of the final porous structure and the resulting effects on the electrical, thermal and mechanical properties

    Effects of High Magnesium Intake on Bone Mineral Status and Lipid Metabolism in Rats

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