107 resultados para 349
Resumo:
The myeloproliferative neoplasms, are characterised by overproduction of myeloid cells. Chronic myeloid leukaemia, polycythaemia vera, essential thrombocythaemia, myelofibrosis and the very rare disorders chronic neutrophilic leukaemia, chronic eosinophilic leukaemia not otherwise specified and mastocytosis are all included in the group. Incidence and prevalence rates reported in the worldwide literature are presented in this review. Survival data on each condition is described. Information on the aetiology of the disorders is discussed including body mass index, diet, smoking and alcohol, allergies, associated medical conditions, occupation and environmental exposures with focus on recent new studies. The aetiology of the myeloproliferative neoplasms remains unknown, and this review of the current state of knowledge highlights the need for further comprehensive research.
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Cyanobacterial toxins present in drinking water sources pose a considerable threat to human health. Conventional water treatment systems have proven unreliable for the removal of these toxins and hence new techniques have been investigated. Previous work has shown that TiO2 photocatalysis effectively destroys microcystin-LR in aqueous solutions, however, a variety of by-products were generated. In this paper, we report a mechanistic study of the photocatalytic destruction of microcystin-LR. In particular, the toxicity by-products of the process have been studied using both brine shrimp and protein phosphatase bioassays.
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Aqueous solutions of CO2 containing tetramethylammonium chloride were photolysed with visible light in the presence of colloidal ZnS to yield tartaric acid, glyoxylic acid, oxalic acid, formic acid and formaldehyde.
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Smith et al. (Reports, 27 February 2015, p. 998) identify wheat DNA from an 8000-calendar-years-before-the-present archaeological site in southern England and conclude that wheat was traded to Britain 2000 years before the arrival of agriculture. The DNA samples are not dated, either directly or from circumstantial evidence, so there is no chronological evidence to support the claim
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To determine the effect of microbial metabolites on the release of root exudates from perennial ryegrass, seedlings were pulse labelled with [14C]-CO2 in the presence of a range of soil micro-organisms. Microbial inoculants were spatially separated from roots by Millipore membranes so that root infection did not occur. Using this technique, only microbial metabolites affected root exudation. The effect of microbial metabolites on carbon assimilation and distribution and root exudation was determined for 15 microbial species. Assimilation of a pulse label varied by over 3.5 fold, dependent on inoculant. Distribution of the label between roots and shoots also varied with inoculant, but the carbon pool that was most sensitive to inoculation was root exudation. In the absence of a microbial inoculant only 1% of assimilated label was exuded. Inoculation of the microcosms always caused an increase in exudation but the percentage exuded varied greatly, within the range of 3-34%. © 1995 Kluwer Academic Publishers.
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Key challenges for contemporary neorepublicans are identified and explored. Firstly, the attempt to maintain a sharp line between neorepublicanism and the wider family of liberal–egalitarian political theories is questioned. Secondly, in response to challenges from democratic theorists, it is argued that republicanism needs to effect an appropriate rapprochement with the ideal of collective political autonomy, on which it appears to rely. Thirdly, it is argued that freedom as non-domination draws so heavily on the idea of equal respect that it is hard to maintain that freedom is the sole value grounding the theory. Finally, it is suggested that the consequentialist framework of Pettit’s theory imposes significant limitations on republican social justice. How republican political theorists respond to these challenges will determine whether the neorepublican revival will be seen as enriching contemporary debates about democracy and social justice or as a retreat from more ambitious accounts of freedom and justice.
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Protocols of systematic reviews and meta-analyses allow for planning and documentation of review methods, act as a guard against arbitrary decision making during review conduct, enable readers to assess for the presence of selective reporting against completed reviews, and, when made publicly available, reduce duplication of efforts and potentially prompt collaboration. Evidence documenting the existence of selective reporting and excessive duplication of reviews on the same or similar topics is accumulating and many calls have been made in support of the documentation and public availability of review protocols. Several efforts have emerged in recent years to rectify these problems, including development of an international register for prospective reviews (PROSPERO) and launch of the first open access journal dedicated to the exclusive publication of systematic review products, including protocols (BioMed Central's Systematic Reviews). Furthering these efforts and building on the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guidelines, an international group of experts has created a guideline to improve the transparency, accuracy, completeness, and frequency of documented systematic review and meta-analysis protocols--PRISMA-P (for protocols) 2015. The PRISMA-P checklist contains 17 items considered to be essential and minimum components of a systematic review or meta-analysis protocol.This PRISMA-P 2015 Explanation and Elaboration paper provides readers with a full understanding of and evidence about the necessity of each item as well as a model example from an existing published protocol. This paper should be read together with the PRISMA-P 2015 statement. Systematic review authors and assessors are strongly encouraged to make use of PRISMA-P when drafting and appraising review protocols.
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Alkali activated binders, based on ash and slag, also known as geopolymers, can play a key role in reducing the carbon footprint of the construction sector by replacing ordinary Portland cement in some concretes. Since 1970s, research effort has been ongoing in many research institutions. In this study, pulverized fuel ash (pfa) from a UK power plant, ground granulated blast furnace slag (ggbs) and combinations of the two have been investigated as geopolymer binders for concrete applications. Activators used were sodium hydroxide and sodium silicate solutions. Mortars with sand/binder ratio of 2.75 with several pfa and ggbs combinations have been mixed and tested. The optimization of alkali dosage (defined as the Na2O/binder mass ratio) and modulus (defined as the Na2O/SiO2 mass ratio) resulted in strengths in excess of 70 MPa for tested mortars. Setting time and workability have been considered for the identification of the best combination of pfa/ggbs and alkali activator dosage for different precast concrete products. Geopolymer concrete building blocks have been replicated in laboratory and a real scale factory trial has been successfully carried out. Ongoing microstructural characterization is aiming to identify reaction products arising from pfa/ggbs combinations.
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Testing the hypothesis that the concept of translation is evaluative rather than merely descriptive, Blumczyński analyses its increasingly popular use in three areas: political discourse, life writing and biomedical publications. He argues that translation as an evaluative concept is concerned with profound rather than superficial issues: to translate something is to assert its significance and value. At the same time, translation brings to the surface real and authentic things, producing its therapeutic value: it makes us more visible to ourselves, exposes pretences and thus brings relief. Finally, translation delivers on its own ethical imperative by breaking the spell of proverbial good intentions and bringing things to completion.
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Shared services are a popular reform for governments under financial pressure. The hope is to reduce overheads and increase efficiency by providing support services like HR, finance and procurement once to multiple agencies. Drawing on insights from organization theory and political science, we identify five risks that shared services won’t live up to current expectations. We illustrate each with empirical evidence from the UK, Ireland and further afield, and conclude with suggestions on how to manage these risks.
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High resolution soft x-ray photoemission spectroscopy (SXPS) have been used to study the high temperature thermal stability of ultra-thin atomic layer deposited (ALD) HfO2 layers (∼1 nm) on sulphur passivated and hydrofluoric acid (HF) treated germanium surfaces. The interfacial oxides which are detected for both surface preparations following HfO2 deposition can be effectively removed by annealing upto 700 °C without any evidence of chemical interaction at the HfO2/Ge interface. The estimated valence and conduction band offsets for the HfO2/Ge abrupt interface indicated that effective barriers exist to inhibit carrier injection.
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The risks associated with zoonotic infections transmitted by companion animals are a serious public health concern: the control of zoonoses incidence in domestic dogs, both owned and stray, is hence important to protect human health. Integrated dog population management (DPM) programs, based on the availability of information systems providing reliable data on the structure and composition of the existing dog population in a given area, are fundamental for making realistic plans for any disease surveillance and action system. Traceability systems, based on the compulsory electronic identification of dogs and their registration in a computerised database, are one of the most effective ways to ensure the usefulness of DPM programs. Even if this approach provides many advantages, several areas of improvement have emerged in countries where it has been applied. In Italy, every region hosts its own dog register but these are not compatible with one another. This paper shows the advantages of a web-based-application to improve data management of dog regional registers. The approach used for building this system was inspired by farm animal traceability schemes and it relies on a network of services that allows multi-channel access by different devices and data exchange via the web with other existing applications, without changing the pre-existing platforms. Today the system manages a database for over 300,000 dogs registered in three different Italian regions. By integrating multiple Web Services, this approach could be the solution to gather data at national and international levels at reasonable cost and creating a traceability system on a large scale and across borders that can be used for disease surveillance and development of population management plans. © 2012 Elsevier B.V.
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While personalised cancer medicine holds great promise, targeting therapies to the biological characteristics of patients is limited by the number of validated biomarkers currently available. The implementation of biomarkers has undergone many challenges with few biomarkers reaching cancer patients in the clinic. There have been many biomarkers that have been published and claimed to be therapeutically useful, but few become part of the clinical decision-making process due to technical, validation and market access issues. To reduce this attrition rate, there is a significant need for policy makers and reimbursement agencies to define specific evidence requirements for the introduction of biomarkers into clinical practice. Once these requirements are more clearly defined, in an analogous manner to pharmaceuticals, researchers and diagnostic companies can better focus their biomarker research and development on meeting these specific requirements, which should lead to the more rapid introduction of new molecular oncology tests for patient benefit.