11,233 research outputs found

    Current status of laboratory and imaging diagnosis of neonatal necrotizing enterocolitis

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    Necrotizing enterocolitis continues to be a devastating disease process for very low birth weight infants in Neonatal Intensive Care Units. The aetiology and pathogenesis of necrotizing enterocolitis are not definitively understood. It is known that necrotizing enterocolitis is secondary to a complex interaction of multiple factors that results in mucosal damage, which leads to intestinal ischemia and necrosis. Advances in neonatal care, including resuscitation and ventilation support technology, have seen increased survival rates among premature neonates and a concomitant detection in the incidence of this intestinal disease.Diagnosis can be difficult, and identifying infants at the onset of disease remains a challenge. Early diagnosis, which relies on imaging findings, and initiation of prompt therapy are essential to limit morbidity and mortality. Moreover, early management is critical and life-saving.This review summarizes what is known on the laboratory and instrumental diagnostic strategies needed to improve neonatal outcomes and, possibily, to prevent the onset of an overt necrotizing enterocolitis

    Sulfur-containing histidine compounds inhibit γ-glutamyl transpeptidase activity in human cancer cells

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    γ-Glutamyl transpeptidase (GGT) is an enzyme located on the surface of cellular membranes and involved in GSH metabolism and maintenance of redox homeostasis. High GGT expression on tumor cells is associated with increased cell proliferation and resistance against chemotherapy. GGT inhibitors evaluated so far in clinical trials are too toxic for human use. In this study, using enzyme kinetics analyses, we demonstrate that ovothiols, 5(Nπ)-methyl thiohistidines of marine origin, act as noncompetitive inhibitors of GGT, with an apparent Ki of 21 μM, when we fixed the concentrations of the donor substrate. We found that these compounds are more potent than the known GGT inhibitor 6-diazo-5-oxo-L-norleucine and are not toxic toward human embryonic cells. In particular, cellular process-specific fluorescence-based assays revealed that ovothiols induce a mixed cell-death phenotype of apoptosis and autophagy in GGT-overexpressing cell lines, including human liver cancer and chronic B leukemic cells. The findings of our study provide the basis for further development of 5-thiohistidines as therapeutics for GGT-positive tumors and highlight that GGT inhibition is involved in autophagy

    Understanding nurses' dual practice: A scoping review of what we know and what we still need to ask on nurses holding multiple jobs

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    © 2018 The Author(s). Background: Mounting evidence suggests that holding multiple concurrent jobs in public and private (dual practice) is common among health workers in low- as well as high-income countries. Nurses are world's largest health professional workforce and a critical resource for achieving Universal Health Coverage. Nonetheless, little is known about nurses' engagement with dual practice. Methods: We conducted a scoping review of the literature on nurses' dual practice with the objective of generating hypotheses on its nature and consequences, and define a research agenda on the phenomenon. The Arksey and O'Malley's methodological steps were followed to develop the research questions, identify relevant studies, include/exclude studies, extract the data, and report the findings. PRISMA guidelines were additionally used to conduct the review and report on results. Results: Of the initial 194 records identified, a total of 35 met the inclusion criteria for nurses' dual practice; the vast majority (65%) were peer-reviewed publications, followed by nursing magazine publications (19%), reports, and doctoral dissertations. Twenty publications focused on high-income countries, 16 on low- or middle-income ones, and two had a multi country perspective. Although holding multiple jobs not always amounted to dual practice, several ways were found for public-sector nurses to engage concomitantly in public and private employments, in regulated as well as in informal, casual fashions. Some of these forms were reported as particularly prevalent, from over 50% in Australia, Canada, and the UK, to 28% in South Africa. The opportunity to increase a meagre salary, but also a dissatisfaction with the main job and the flexibility offered by multiple job-holding arrangements, were among the reported reasons for engaging in these practices. Discussion and conclusions: Limited and mostly circumstantial evidence exists on nurses' dual practice, with the few existing studies suggesting that the phenomenon is likely to be very common and carry implications for health systems and nurses' welfare worldwide. We offer an agenda for future research to consolidate the existing evidence and to further explore nurses' motivation; without a better understanding of nurse dual practice, thiswill continue to be a largely 'hidden' element in nursing workforce policy and practice, with an unclear impact on the delivery of care

    Defects, Rigid Holography and CC-theorems

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    We consider a general scalar QFT with a linear defect in D=4ϵD=4-\epsilon and a surface defect in D=6ϵD=6-\epsilon. Using holography and the Hamilton-Jacobi formalism, we show that the β\beta functions controlling the defect RG flow are the gradient of the entropy function. In the case of conformal field theories, this allows the proof that the relevant CC-functions decrease monotonically along the RG flow. We provide evidence that this property also holds in the full quantum theory for general scalar field theories. An obstruction to the gradient property seems to appear at two loop order when fermions are added.Comment: 6 pages, no figures; v2: published versio

    RG Flows and Stability in Defect Field Theories

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    We investigate defects in scalar field theories in four and six dimensions in a double-scaling (semiclassical) limit, where bulk loops are suppressed and quantum effects come from the defect coupling. We compute β\beta -functions up to four loops and find that fixed points satisfy dimensional disentanglement -- i.e. their dependence on the space dimension is factorized from the coupling dependence -- and discuss some physical implications. We also give an alternative derivation of the β\beta functions by computing systematic logarithmic corrections to the Coulomb potential. In this natural scheme, β\beta functions turn out to be a gradient of a `Hamiltonian' function H{\cal H}. We also obtain closed formulas for the dimension of scalar operators and show that instabilities do not occur for potentials bounded from below. The same formulas are reproduced using Rigid Holography.Comment: 35 pages, 1 figure; v2: added reference

    Random Graph-Homomorphisms and Logarithmic Degree

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    A graph homomorphism between two graphs is a map from the vertex set of one graph to the vertex set of the other graph, that maps edges to edges. In this note we study the range of a uniformly chosen homomorphism from a graph G to the infinite line Z. It is shown that if the maximal degree of G is `sub-logarithmic', then the range of such a homomorphism is super-constant. Furthermore, some examples are provided, suggesting that perhaps for graphs with super-logarithmic degree, the range of a typical homomorphism is bounded. In particular, a sharp transition is shown for a specific family of graphs C_{n,k} (which is the tensor product of the n-cycle and a complete graph, with self-loops, of size k). That is, given any function psi(n) tending to infinity, the range of a typical homomorphism of C_{n,k} is super-constant for k = 2 log(n) - psi(n), and is 3 for k = 2 log(n) + psi(n)

    Monitoring of arthropod infestations on high quality hard wheat in southern Italy

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    The results of a survey in 2006-2009 on high quality hard wheat, coming from 31 different storage centers located in Southern Italy, are reported. About 300 samples were analyzed by visual test, while 891 by both sieving and biological test. For the three different kinds of test the infesting species are listed and their relative incidence on the samples is reported. The most widespread species in the samples belonged to the order Coleoptera, i.e. Sitophilus granarius, Rhyzopertha dominica and Oryzaephilus spp., while Lepidoptera were less abundant. The results are discussed with the aim of providing the storage centre operators with helpful information on the correct monitoring strategies to adopt in case of arthropod infestations in high-quality hard-wheat warehouses.Keywords: Stored grain, Insects, Sampling, Coleoptera, Ital

    Epigenome chaos: Stochastic and deterministic dna methylation events drive cancer evolution

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    Cancer evolution is associated with genomic instability and epigenetic alterations, which contribute to the inter and intra tumor heterogeneity, making genetic markers not accurate to monitor tumor evolution. Epigenetic changes, aberrant DNA methylation and modifications of chromatin proteins, determine the “epigenome chaos”, which means that the changes of epigenetic traits are randomly generated, but strongly selected by deterministic events. Disordered changes of DNA methylation profiles are the hallmarks of all cancer types, but it is not clear if aberrant methylation is the cause or the consequence of cancer evolution. Critical points to address are the profound epigenetic intra-and inter-tumor heterogeneity and the nature of the heterogeneity of the methylation patterns in each single cell in the tumor population. To analyze the methylation heterogeneity of tumors, new technological and informatic tools have been developed. This review discusses the state of the art of DNA methylation analysis and new approaches to reduce or solve the complexity of methylated alleles in DNA or cell populations

    Quantum dot opto-mechanics in a fully self-assembled nanowire

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    We show that fully self-assembled optically-active quantum dots (QDs) embedded in MBE-grown GaAs/AlGaAs core-shell nanowires (NWs) are coupled to the NW mechanical motion. Oscillations of the NW modulate the QD emission energy in a broad range exceeding 14 meV. Furthermore, this opto-mechanical interaction enables the dynamical tuning of two neighboring QDs into resonance, possibly allowing for emitter-emitter coupling. Both the QDs and the coupling mechanism -- material strain -- are intrinsic to the NW structure and do not depend on any functionalization or external field. Such systems open up the prospect of using QDs to probe and control the mechanical state of a NW, or conversely of making a quantum non-demolition readout of a QD state through a position measurement.Comment: 20 pages, 6 figure
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