100 research outputs found

    Evaluation of Phenotypic Carbapenemase Production in blaOXA-48 positive K. pneumoniae Isolates by Modified Hodge and Carbapenemase Inactivation Tests

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    Aim:In recent years, increasing colonization rates of K. pneumoniae in patients with immunosuppression, long hospital stay, invasive devices and treated with broad spectrum antibiotics lead to resistant infections. In this investigate, we aimed to investigate carbapenem resistance in multiresistant K. pneumoniae isolates derived from clinical specimens by phenotypic and genotypic methods.Materials and Methods:In July 2014, 51 K. pneumoniae isolates which were derived from clinical specimens were evaluated. Identification and antibiotic susceptibility tests of isolates were studied with automatized system. Verification of carbapenem resistance were studied with with gradient strip tests. Identification of carbapenemase resistant genes were studied with with “in house” PCR. Phenotypic tests including Modified Hodge test (MHT) and Carbapenemase Inactivation Method (CIM) were applied to all isolates. We re-studied all carbapenems for the isolates with incompatible results.Results:Resistance rates of all isolates to imipenem, meropenem and ertapenem were 78.43%, 60.78% and 96.08%, respectively. 42 of 51 isolates were positive with MHT and 43 of 51 isolates were positive with CIM. blaOXA-48 gene was identified in 42 isolates with PCR. nine isolates which were negative for blaOXA-48 and other carbapenemases gene were negative with MHT and eight isolates which were negative for blaOXA-48 gene were negative with CIM.Conclusion:MHT and CIM are fast and easy methods for the identification of carbapenemase presence. CIM is an easy screening test, but one should be cautious for false negative and positive results. We suggest that modification of the test with carbapenem discs should decrease false negative results

    Low Q^2 measurements of the proton form factor ratio mupGE/GMmu_p G_E / G_M

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    We present an updated extraction of the proton electromagnetic form factor ratio, mu_p G_E/G_M, at low Q^2. The form factors are sensitive to the spatial distribution of the proton, and precise measurements can be used to constrain models of the proton. An improved selection of the elastic events and reduced background contributions yielded a small systematic reduction in the ratio mu_p G_E/G_M compared to the original analysis.Comment: 12 pages, 5 figures, archival paper for proton form factor extraction from Jefferson Lab "LEDEX" experimen

    The Proton Elastic Form Factor Ratio at Low Momentum Transfer

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    High precision measurements of the proton elastic form factor ratio have been made at four-momentum transfers, Q^2, between 0.2 and 0.5 GeV^2. The new data, while consistent with previous results, clearly show a ratio less than unity and significant differences from the central values of several recent phenomenological fits. By combining the new form-factor ratio data with an existing cross-section measurement, one finds that in this Q^2 range the deviation from unity is primarily due to GEp being smaller than the dipole parameterization.Comment: 5 pages, 2 figure

    Collateral Circulation and Outcome in Atherosclerotic Versus Cardioembolic Cerebral Large Vessel Occlusion

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    Background and Purpose- Due to chronic hypoperfusion, cervical atherosclerosis may promote cerebral collateral circulation. We hypothesized that patients with ischemic stroke due to cervical carotid atherosclerosis have a more extensive collateral circulation and better outcomes than patients with cardioembolism. We tested this hypothesis in a population of patients who underwent endovascular treatment for large vessel occlusion. Methods- From the MR-CLEAN Registry (Multicenter Randomized Controlled Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands), we selected consecutive adult endovascular treatment patients (March 2014 to June 2016) with acute ischemic stroke due to anterior circulation large vessel occlusion and compared patients with cervical carotid artery stenosis >50% to those with cardioembolic etiology. The primary outcome was collateral score, graded on a 4-point scale. Secondary outcomes included the modified Rankin Scale (mRS) score and mortality at 90 days. We performed multivariable regression analyses and adjusted for potential confounders. Results- Of 1627 patients in the Registry, 190 patients with cervical carotid atherosclerosis and 476 with cardioembolism were included. Patients with cervical carotid atherosclerosis were younger (median 69 versus 76 years, P<0.001), more often male (67% versus 47%, P<0.001), more often had an internal carotid artery terminus occlusion (33% versus 18%, P<0.001), and a lower prestroke mRS (mRS score, 0-2; 96% versus 85%, P<0.001), than patients with cardioembolism. Stroke due to cervical carotid atherosclerosis was associated with higher collateral score (adjusted common odds ratio, 1.67 [95% CI, 1.17-2.39]) and lower median mRS at 90 days (adjusted common odds ratio, 1.45 [95% CI, 1.03-2.05]) compared with cardioembolic stroke. There was no statistically significant difference in proportion of mRS 0-2 (aOR, 1.36 [95% CI, 0.90-2.07]) or mortality at 90 days (aOR, 0.80 [95% CI, 0.48-1.34]). Conclusions- Patients with stroke due to cervical carotid atherosclerosis had a more extensive cerebral collateral circulation and a slightly better median mRS at 90 days than patients with cardioembolic stroke

    Prognostic value of gross tumor volume delineated by FDG-PET-CT based radiotherapy treatment planning in patients with locally advanced pancreatic cancer treated with chemoradiotherapy

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    <p>Abstract</p> <p>Background</p> <p>We aimed to assess whether gross tumor volume (GTV) determined by fusion of contrast-enhanced computerized tomography (CT) and 18F-fluoro-deoxy-D-glucose positron emission tomography-CT (FDG-PET-CT) based radiotherapy planning could predict outcomes, namely overall survival (OS), local-regional progression-free survival (LRPFS), and progression-free survival (PFS) in cases with locally advanced pancreas cancer (LAPC) treated with definitive concurrent chemoradiotherapy.</p> <p>Methods</p> <p>A total of 30 patients with histological proof of LAPC underwent 50.4 Gy (1.8 Gy/28 fractions) of radiotherapy concurrent with continuously infused 5-FU followed by 4 to 6 courses of maintenance gemcitabine. Target volume delineations were performed on FDG-PET-CT-based RTP. Patients were stratified into 2 groups: GTV lesser (GTV<sub>L</sub>) versus greater (GTV<sub>G</sub>) than cut off value determined by receiver operating characteristic (ROC) analysis, and compared in terms of OS, LRPFS and PFS.</p> <p>Results</p> <p>Median GTV delineated according to the FDG-PET-CT data was 100.0 cm<sup>3</sup>. Cut off GTV value determined from ROC curves was 91.1 cm<sup>3</sup>. At a median follow up of 11.2 months, median OS, LRPFS and PFS for the entire population were 10.3, 7.8 and 5.7 months, respectively. Median OS, LRPFS and PFS for GTV<sub>L </sub>and GTV<sub>G </sub>cohorts were 16.3 vs. 9.5 (<it>p </it>= 0.005), 11.0 vs. 6.0 (<it>p </it>= 0.013), and 9.0 vs. 4.8 months (<it>p </it>= 0.008), respectively.</p> <p>Conclusions</p> <p>The superior OS, LRPFS and PFS observed in GTV<sub>L </sub>patients over GTV<sub>G </sub>ones suggests a potential for FDG-PET-CT-defined GTV size in predicting outcomes of LAPC patients treated with definitive C-CRT, which needs to be validated by further studies with larger cohorts.</p

    Deafening silence? Marxism, international historical sociology and the spectre of Eurocentrism

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    Approaching the centenary of its establishment as a formal discipline, International Relations today challenges the ahistorical and aspatial frameworks advanced by the theories of earlier luminaries. Yet, despite a burgeoning body of literature built on the transdisciplinary efforts bridging International Relations and its long-separated nomothetic relatives, the new and emerging conceptual frameworks have not been able to effectively overcome the challenge posed by the ‘non-West’. The recent wave of international historical sociology has highlighted possible trajectories to problematise the myopic and unipolar conceptions of the international system; however, the question of Eurocentrism still lingers in the developing research programmes. This article interjects into the ongoing historical materialist debate in international historical sociology by: (1) conceptually and empirically challenging the rigid boundaries of the extant approaches; and (2) critically assessing the postulations of recent theorising on ‘the international’, capitalist states-system/geopolitics and uneven and combined development. While the significance of the present contributions in international historical sociology should not be understated, it is argued that the ‘Eurocentric cage’ still occupies a dominant ontological position which essentially silences ‘connected histories’ and conceals the role of inter-societal relations in the making of the modern states-system and capitalist geopolitics

    Temperature Effects Explain Continental Scale Distribution of Cyanobacterial Toxins

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    Insight into how environmental change determines the production and distribution of cyanobacterial toxins is necessary for risk assessment. Management guidelines currently focus on hepatotoxins (microcystins). Increasing attention is given to other classes, such as neurotoxins (e.g., anatoxin-a) and cytotoxins (e.g., cylindrospermopsin) due to their potency. Most studies examine the relationship between individual toxin variants and environmental factors, such as nutrients, temperature and light. In summer 2015, we collected samples across Europe to investigate the effect of nutrient and temperature gradients on the variability of toxin production at a continental scale. Direct and indirect effects of temperature were the main drivers of the spatial distribution in the toxins produced by the cyanobacterial community, the toxin concentrations and toxin quota. Generalized linear models showed that a Toxin Diversity Index (TDI) increased with latitude, while it decreased with water stability. Increases in TDI were explained through a significant increase in toxin variants such as MC-YR, anatoxin and cylindrospermopsin, accompanied by a decreasing presence of MC-LR. While global warming continues, the direct and indirect effects of increased lake temperatures will drive changes in the distribution of cyanobacterial toxins in Europe, potentially promoting selection of a few highly toxic species or strains.Peer reviewe

    Antenna Designs for CubeSat-Borne, Continuous-Waveform Radar

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    CubeSat-borne radar has many potential applications in space exploration including tracking, imaging, and weather prediction. A continuous-waveform radar has advantages of compact size and low power consumption, making it suitable to implement on small platforms such as CubeSats. This paper demonstrates an isolation technique that overcomes the self-interference between the transmit and receive antennas inherent to continuous-waveform radar. The presented approach combines opposite circularly polarized antennas on two deployed solar panels to minimize the self-interference. The prototype antennas are tested on a 6U CubeSat frame and the results show more than 40 dB isolation, satisfying the power budget requirements
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