1,258 research outputs found

    The role of 18F-FDG-PET/CT in the management of patients with high-risk breast cancer: case series and guideline comparison

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    Objectives: In grade III-IV breast cancer, dissemination of disease needs to be assessed. Until now this was done by conventional imaging (liver ultrasonography, chest X-ray and bone scintigraphy), but evidence favoring the use of FDG-PET/CT is accumulating. Methods: Patients with high-risk breast cancer, who had received conventional imaging and FDG-PET/CT, were included. Patients were staged and assigned a treatment after 1) conventional imaging and 2) FDG-PET/CT, both by a multidisciplinary oncology team. Equivocal FDG-PET/CT findings were histologically confirmed. Results: 16 patients were included (mean age 59 years). TNM-stage changed in 5 patients (31%) after FDG-PET/CT. In 3 patients (19%) unknown distant metastases were detected by FDG-PET/CT. An adjustment of treatment took place in 4 patients (25%). Conclusions: Our case series emphasizes the role of FDG-PET/CT in the staging of high-risk breast carcinoma, especially in the assessment of distant metastases. We suggest replacing conventional imaging with FDG-PET/CT

    Apolipoprotein A–I binding to anionic vesicles and lipopolysaccharides: Role for lysine residues in antimicrobial properties

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    AbstractHuman apolipoprotein A–I (apoA–I) is a 28kDa protein and a major component of high-density lipoproteins, mediating several essential metabolic functions related to heart disease. In the present study the potential protective role against bacterial pathogens was explored. ApoA–I suppressed bacterial growth of Escherichia coli and Klebsiella pneumoniae. The protein was able to bind lipopolysaccharides and showed a strong preference for bilayer vesicles made of phosphatidylglycerol over phosphatidylcholine. Lysine side chains of apoA–I were acetylated to evaluate the importance of electrostatic forces in the binding interaction with both membrane components. Electrophoresis properties, dot blot analysis, circular dichroism, and fluorescence spectroscopy to probe for changes in protein structure indicated that the acetylated protein displayed a strongly reduced lipopolysaccharide and phosphatidylglycerol binding. A mutant containing only the N-terminal domain of apoA–I also showed a reduced ability to interact with the membrane components, although to a lesser extent. These results indicate the potential for apoA–I to function as an antimicrobial protein and exerts this function through lysine residues

    Forages for Conservation and Improved Soil Quality

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    Forages provide several soil benefits, including reduced soil erosion, reduced water runoff, improved soil physical properties, increased soil carbon, increased soil biologic activity, reduced soil salinity, and improved land stabilization and restoration when grown continuously or as part of a crop rotation. Ongoing research and synthesis of knowledge have improved our understanding of how forages alter and protect soil resources, thus providing producers, policymakers, and the general public information regarding which forage crops are best suited for a specific area or use (e.g. hay, grazing or bioenergy feedstock). Forages can be produced in forestland, range, pasture, and cropland settings. These land use types comprise 86% of non-Federal United States rural lands (Table 12.1). In the United States, active forage production occurs on 22.6 million ha and is used for hay, haylage, grass silage, and greenchop (Table 12.2). Forages are used as cover crops in several production systems, and approximately 4.2 million ha were recently planted in cover crops (Table 12.3). Currently, the highest cover crop use rates, as a percentage of total cropland within a given state, occur in the northeastern United States. Globally, permanent meadows and pastures account for over 3.3 billion ha, greater than arable land and permanent crops combined (Table 12.4). Within all regions of the world, except Europe, permanent meadows and pastures are a greater proportion of land cover than permanent crops. Pasture management information and resources are available for countries around the world (FAO 2017a,b). As seen in Tables 12.1–12.4, forages are used globally and can provide soil benefits across varied soil and climate types

    First-principles study of nucleation, growth, and interface structure of Fe/GaAs

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    We use density-functional theory to describe the initial stages of Fe film growth on GaAs(001), focusing on the interplay between chemistry and magnetism at the interface. Four features appear to be generic: (1) At submonolayer coverages, a strong chemical interaction between Fe and substrate atoms leads to substitutional adsorption and intermixing. (2) For films of several monolayers and more, atomically abrupt interfaces are energetically favored. (3) For Fe films over a range of thicknesses, both Ga- and As-adlayers dramatically reduce the formation energies of the films, suggesting a surfactant-like action. (4) During the first few monolayers of growth, Ga or As atoms are likely to be liberated from the interface and diffuse to the Fe film surface. Magnetism plays an important auxiliary role for these processes, even in the dilute limit of atomic adsorption. Most of the films exhibit ferromagnetic order even at half-monolayer coverage, while certain adlayer-capped films show a slight preference for antiferromagnetic order.Comment: 11 two-column pages, 12 figures, to appear in Phys. Rev.

    Stable and Metastable Structures of Cobalt on Cu(001): An ab initio Study

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    We report results of density-functional theory calculations on the structural, magnetic, and electronic properties of (1x1)-structures of Co on Cu(001) for coverages up to two monolayers. In particular we discuss the tendency towards phase separation in Co islands and the possibility of segregation of Cu on top of the Co-film. A sandwich structure consisting of a bilayer Co-film covered by 1ML of Cu is found to be the lowest-energy configuration. We also discuss a bilayer c(2x2)-alloy which may form due to kinetic reasons, or be stabilized at strained surface regions. Furthermore, we study the influence of magnetism on the various structures and, e.g., find that Co adlayers induce a weak spin-density wave in the copper substrate.Comment: 11 pages including 4 figures. Related publications can be found at http://www.fhi-berlin.mpg.de/th/paper.htm

    Superconductivity from correlated hopping

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    We consider a chain described by a next-nearest-neighbor hopping combined with a nearest-neighbor spin flip. In two dimensions this three-body term arises from a mapping of the three-band Hubbard model for CuO2_2 planes to a generalized t−Jt-J model and for large O-O hopping favors resonance-valence-bond superconductivity of predominantly dd-wave symmetry. Solving the ground state and low-energy excitations by analytical and numerical methods we find that the chain is a Luther-Emery liquid with correlation exponent Kρ=(2−n)2/2K_{\rho} = (2-n)^2/2, where nn is the particle density.Comment: 10 pages, RevTeX 3.0 + 2 PostScript figs. Accepted for publication in Phys.Rev.

    Line shapes of dynamical correlation functions in Heisenberg chains

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    We calculate line shapes of correlation functions by use of complete diagonalization data of finite chains and analytical implications from conformal field theory, density of states, and Bethe ansatz. The numerical data have different finite size accuracy in case of the imaginary and real parts in the frequency and time representations of spin-correlation functions, respectively. The low temperature, conformally invariant regime crosses over at T∗≈0.7JT^*\approx 0.7J to a diffusive regime that in turn connects continuously to the high temperature, interacting fermion regime. The first moment sum rule is determined.Comment: 13 pages REVTEX, 18 figure

    Adherence to Guidelines for Adult (Non-GIST) Soft Tissue Sarcoma in the Netherlands: A Plea for Dedicated Sarcoma Centers

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    Introduction: Optimal management of soft tissue sarcoma (STS) remains a challenge. A nationwide survey assessed the quality of STS care in the Netherlands, thereby aiming to identify potentialities for improvement through more centralized disease management. Methods: From the Netherlands Cancer Registry (NCR), data were obtained on 3317 adult STS patients (excluding gastrointestinal stromal tumor, GIST) diagnosed in 2006–2011. Logistic regression models were employed to compare outcomes on selected clinical indicators reflecting prevailing STS guidelines between high-volume (≄10 resections annually) and low-volume (<10 resections) hospitals, between academic and general hospitals, and between sarcoma research centers and other hospitals, adjusted for case mix. Analyses were performed on imputed datasets (m = 50), generated through multiple imputations by chained equations. Results: Overall, 89% of patients underwent surgical resection. Resection status remained unknown in 24% (excluding those with metastasized disease), and grade was not documented for one-third of tumors. Microscopic residual disease was detected in 20% with an increased risk for older patients, larger and deeply located tumors, and those located in the (retro)peritoneum or upper extremity. Almost half of patients with an R1 resection re

    Single hole dynamics in the t-J model on two- and three-leg ladders

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    The dynamics of a single hole in the t-J model on two- (2LL) and three- (3LL) leg ladders is studied using a recently developed quantum Monte Carlo algorithm. For the 2LL it is shown that in addition to the most pronounced features of the spectral function, well described by the limit of strong coupling along the rungs, a clear shadow band appears in the antibonding channel. Moreover, both the bonding band and its shadow have a finite quasiparticle (QP) weight in the thermodynamic limit. For strong coupling along the rungs of the 3LL, the low-energy spectrum in the antisymmetric channel is similar to a one-dimensional chain, whereas in the two symmetric channels it resembles the 2LL. The QP weight vanishes in the antisymmetric channel, but is finite in the symmetric one

    A complex proinflammatory cascade mediates the activation of HSCs upon LPS exposure in vivo

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    Infections are a key source of stress to the hematopoietic system. While infections consume short-lived innate immune cells, their recovery depends on quiescent hematopoietic stem cells (HSCs) with long-term self-renewal capacity. Both chronic inflammatory stress and bacterial infections compromise competitive HSC capacity and cause bone marrow failure. However, our understanding of how HSCs act during acute and contained infections remains incomplete. Here, we used advanced chimeric and genetic mouse models in combination with pharmacological interventions to dissect the complex nature of the acute systemic response of HSCs to lipopolysaccharide (LPS), a well-established model for inducing inflammatory stress. Acute LPS challenge transiently induced proliferation of quiescent HSCs in vivo. This response was not only mediated via direct LPS-TLR4 conjugation on HSCs, but also involved indirect TLR4 signaling in CD115+ monocytic cells, inducing a complex pro-inflammatory cytokine cascade in the bone marrow. Downstream of LPS-TLR4 signaling, the combined action of pro-inflammatory cytokines such as IFNα, IFNÎł, TNFα, IL-1α, IL-1ÎČ and many others is required to mediate full HSC activation in vivo. Together, our study reveals detailed mechanistic insights into the interplay of proinflammatory cytokine-induced molecular pathways and cell types that jointly orchestrate the complex process of emergency hematopoiesis and HSC activation upon LPS exposure in vivo
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