782 research outputs found

    Prognostic factors for important clinical outcomes in patients with a severe infection

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    Patients who are admitted with a suspicion of a severe infection usually enter the hospital through the emergency department (ED). The recognition of prognostic factors in an early stage affects further treatment and might improve clinical outcomes. WE EXAMINED POSSIBLE PROGNOSTIC FACTORS FOR FOUR IMPORTANT OUTCOMES: intensive care unit (ICU) admission, positive blood cultures, mortality and re-admission. All adult patients arriving at the ED with a suspected infection for whom admittance and intravenous (iv) antibiotics were indicated were included between March and December 2006. Possible prognostic variables were obtained from medical history, physical examination and laboratory results during the ED presentation. Data were analysed using logistic regression analysis. A total of 295 ED patients were evaluated, of whom 27 were referred to the ICU, 62 had a positive blood culture, 16 died and 48 were re-admitted. In multivariate analysis, patients with a respiration rate of >25/min were at higher risk for ICU admission. Patients with a positive blood culture had a higher heart rate and a higher percentage of segmented neutrophils. Patients who died during admission were more likely to be older, confused and had lower blood pressure. Patients who were re-admitted within 30 days were more likely to be male, younger and less likely to have a positive blood culture. Routine clinical and biochemical information can be used to predict ICU admission, the presence of bacteraemia, mortality and re-admission (within 30 days) and should be taken into consideration for treatment decision

    Asymptotic tunneling conductance in Luttinger liquids

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    Conductance through weak constrictions in Luttinger liquids is shown to vanish with frequency ω\omega as c1ω2+c2ω2/g2c_1 \omega^2 + c_2 \omega^{2/g - 2}, where gg is a dimensionless parameter characterizing the Luttinger liquid phase, and c1c_1 and c2c_2 are nonuniversal constants. The first term arises from the ^^ Coulomb blockade' effect and dominates for g<1/2g < 1/2, whereas the second results from eliminating high-energy modes and dominates for g>1/2g > 1/2.Comment: Latex file + one appended postcript figur

    Functionalised metal-organic frameworks: a novel approach to stabilising single metal atoms

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    We have investigated the potential of metal-organic frameworks for immobilising single atoms of transition metals using a model system of Pd supported on NH2-MIL-101(Cr). Our Transmission Electron Microscopy and in-situ Raman spectroscopy results give evidence for the first time that functionalised metal-organic frameworks may support, isolate and stabilise single atoms of palladium. Using Thermal Desorption Spectroscopy we were able to evaluate the proportion of single Pd atoms. Furthermore, in a combined theoretical-experimental approach, we show that the H-H bonds in a H2 molecule elongate by over 15% through the formation of a complex with single atoms of Pd. Such deformation would affect any hydrogenation reaction and thus the single atoms supported on metal-organic frameworks may become promising single atom catalysts in the future

    Inter-cluster reactivity of Metallo-aromatic and anti-aromatic Compounds and Their Applications in Molecular Electronics: A Theoretical Investigation

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    Local reactivity descriptors such as the condensed local softness and Fukui function have been employed to investigate the inter-cluster reactivity of the metallo-aromatic (Al4Li- and Al4Na-) and anti-aromatic (Al4Li4 and Al4Na4) compounds. We use the concept of group softness and group Fukui function to study the strength of the nucleophilicity of the Al4 unit in these compounds. Our analysis shows that the trend of nucleophilicity of the Al4 unit in the above clusters is as follows; Al4Li- > Al4Na- > Al4Li4 > Al4Na 4 For the first time we have used the reactivity descriptors to show that these clusters can act as electron donating systems and thus can be used as a molecular cathode.Comment: 23 pages, 1 figure and 1 table of conten

    Critical properties of two-dimensional Josephson junction arrays with zero-point quantum fluctuations

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    We present results from an extensive analytic and numerical study of a two-dimensional model of a square array of ultrasmall Josephson junctions. We include the ultrasmall self and mutual capacitances of the junctions, for the same parameter ranges as those produced in the experiments. The model Hamiltonian studied includes the Josephson, EJE_J, as well as the charging, ECE_C, energies between superconducting islands. The corresponding quantum partition function is expressed in different calculationally convenient ways within its path-integral representation. The phase diagram is analytically studied using a WKB renormalization group (WKB-RG) plus a self-consistent harmonic approximation (SCHA) analysis, together with non-perturbative quantum Monte Carlo simulations. Most of the results presented here pertain to the superconductor to normal (S-N) region, although some results for the insulating to normal (I-N) region are also included. We find very good agreement between the WKB-RG and QMC results when compared to the experimental data. To fit the data, we only used the experimentally determined capacitances as fitting parameters. The WKB-RG analysis in the S-N region predicts a low temperature instability i.e. a Quantum Induced Transition (QUIT). We carefully simulations and carry out a finite size analysis of TQUITT_{QUIT} as a function of the magnitude of imaginary time axis LτL_\tau. We find that for some relatively large values of α=EC/EJ\alpha=E_C/E_J (1α2.25)1\leq \alpha \leq 2.25), the LτL_\tau\to\infty limit does appear to give a {\it non-zero} TQUITT_{QUIT}, while for α2.5\alpha \ge 2.5, TQUIT=0T_{QUIT}=0. We use the SCHA to analytically understand the LτL_\tau dependence of the QMC results with good agreement between them. Finally, we also carried out a WKB-RG analysis in the I-N region and found no evidence of a low temperature QUIT, up to lowest order in α1{\alpha}^{-1}Comment: 39 pages, 18 postscript figures, to appear in Phys. Rev.

    Jet Substructure at the Tevatron and LHC: New results, new tools, new benchmarks

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    In this report we review recent theoretical progress and the latest experimental results in jet substructure from the Tevatron and the LHC. We review the status of and outlook for calculation and simulation tools for studying jet substructure. Following up on the report of the Boost 2010 workshop, we present a new set of benchmark comparisons of substructure techniques, focusing on the set of variables and grooming methods that are collectively known as "top taggers". To facilitate further exploration, we have attempted to collect, harmonise, and publish software implementations of these techniques.Comment: 53 pages, 17 figures. L. Asquith, S. Rappoccio, C. K. Vermilion, editors; v2: minor edits from journal revision

    Mineral formation induced by cable bacteria performing long-distance electron transport in marine sediments

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    Cable bacteria are multicellular, filamentous microorganisms that are capable of transporting electrons over centimeter-scale distances. Although recently discovered, these bacteria appear to be widely present in the seafloor, and when active they exert a strong imprint on the local geochemistry. In particular, their electrogenic metabolism induces unusually strong pH excursions in aquatic sediments, which induces considerable mineral dissolution, and subsequent mineral reprecipitation. However, at present, it is unknown whether and how cable bacteria play an active or direct role in the mineral reprecipitation process. To this end we present an explorative study of the formation of sedimentary minerals in and near filamentous cable bacteria using a combined approach of electron microscopy and spectroscopic techniques. Our observations reveal the formation of polyphosphate granules within the cells and two different types of biomineral formation directly associated with multicellular filaments of these cable bacteria: (i) the attachment and incorporation of clay particles in a coating surrounding the bacteria and (ii) encrustation of the cell envelope by iron minerals. These findings suggest a complex interaction between cable bacteria and the surrounding sediment matrix, and a substantial imprint of the electrogenic metabolism on mineral diagenesis and sedimentary biogeochemical cycling. In particular, the encrustation process leaves many open questions for further research. For example, we hypothesize that the complete encrustation of filaments might create a diffusion barrier and negatively impact the metabolism of the cable bacteria.</p

    Optical source of individual pairs of colour-conjugated photons

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    We theoretically demonstrate that Kerr nonlinearity in optical circuits can lead to both resonant four-wave mixing and photon blockade, which can be used for high-yield generation of high-fidelity individual photon pairs with conjugated frequencies. We propose an optical circuit, which, in the optimal pulsed-drive regime, would produce photon pairs at the rate up to 5 × 105  s−1 (0.5 pairs per pulse) with g(2)(0)<10–2g(2)(0)<10−2 for one of the conjugated frequencies. We show that such a scheme can be utilised to generate colour-entangled photons

    Prevalence of asymptomatic bacteriuria in type 2 diabetic subjects with and without microalbuminuria

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    <p>Abstract</p> <p>Background</p> <p>Diabetic subjects, especially women, show high prevalence of asymptomatic bacteriuria (ASB). The aim of the present study was to evaluate the prevalence of ASB in subjects with type 2 diabetes mellitus (T2D) with and without microalbuminuria (MA).</p> <p>Findings</p> <p>A hundred diabetic subjects with MA (53 males/47 females, mean age ± standard deviation: 65.5 ± 11.1 years) and 100 diabetic subjects without MA (52 males/48 females, mean age ± standard deviation: 65.4 ± 11.3 years), consecutively attending the outpatient diabetes clinic of our hospital were recruited in the study. Subjects with overt diabetic nephropathy or nephropathy from other causes were excluded. In addition, subjects with symptoms of urinary track infection or use of antimicrobial drugs in the last 14 days were excluded by the study.</p> <p>Diabetic subjects with MA showed increased prevalence of ASB compared to diabetic subjects without MA (21% versus 8%, P < 0.001, respectively). <it>Escherichia coli </it>was the most prevalent pathogen isolated in diabetic subjects with and without MA (12% versus 3.0%, P = 0.01, respectively) followed by <it>Proteus mirabilis </it>(6% versus 5%, P = 0.75, respectively) and <it>Klebsiella </it>spp (5% versus 1%, P = 0.09, respectively). Univariate logistic analysis showed that ASB was associated with the presence of coronary artery disease [odds ratio (OR): 0.29, 95% Confidence Intervals (95% CI): 0.09-0.95, P = 0.04] and gender (OR: 0.09, 95% CI: 0.02-0.35, P < 0.001) in the diabetic study group with MA.</p> <p>Conclusions</p> <p>ASB is more prevalent among T2D subjects with MA. Screening for ASB is warranted in diabetic patients especially if pyuria is detected in urine analysis since ASB has been found to be a risk factor for developing symptomatic urinary tract infection.</p
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