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Amperometric detection of lactose using -galactosidase immobilized in layer-by-layer films

A direct, low-cost method to determine the concentration of lactose is an important goal with possible impact in various types of industry. In this study, a biosensor is reported that exploits the specific interaction between lactose and the enzyme β-galactosidase (β-Gal) normally employed to process lactose into glucose and galactose for lactose-intolerant people. The biosensor was made with β-Ga

A numerical method for analysis of fracture statistics of glass and simulations of a double ring bending test

The results from a new numerical method for simulating the strength and fracture locations of small glass specimens subjected to double ring bending are compared with experimental data. The method implements the weakest-link principle while assuming the existence of Griffith flaws. A Weibull distribution for the strength is simulated based on a single population of Pareto distributed crack sizes.

Emission and dose characterization of the 1 kHz repetition rate high-Z metal K α source driven by 20 mJ femtosecond pulses

We present the hard X-ray generation of K α lines in high-Z elements – platinum and tungsten – targets using the kHz repetition rate TW-class 850 nm, 10 fs laser pulses. The estimated Pt and W Kα1 X-ray photon flux from the recorded spectrum was 1.3 × 10 7 and 1.4 × 10 7 photons/s, respectively, in 2π solid angle. The calculated values of the photon conversion efficiency were 1.3 × 10 - 8 for

A holocene CO2 record from the stomatal index of subfossil Salix herbacea L. leaves from northern Sweden

A stomatal-based method of palaeo-CO2 estimation has been applied to a temporally detailed sequence of leaves from a high-latitude lake (68°N) in northern Sweden spanning the last 9000 years. The resulting atmospheric CO2 reconstruction documents the onset of a gradual increase c. 5000 years before present indicating that the carbon cycle has not been in steady state over this time. Stable carbon

Plant macrofossil methods and studies : CO2 Reconstruction from Fossil Leaves

This article provides a review of the application of stomatal frequency analysis to fossil leaves in the reconstruction of past atmospheric CO2 concentrations. It presents the physiological basis of the method, an overview of its application to leaves of Quaternary age, and an assessment of its potential and limitations. It also includes a description of the successive stages in a stomatal frequen

The strong coupling from ALEPH tau decays

The strong coupling from ALEPH tau decays. We use the publically available non-strange spectral function from ALEPH tau decays to critically analyze the different determinations of αs(mτ2) that can be found in the literature and the numerical impact of their possible weaknesses. We also introduce some novel approaches. We find that perturbative uncertainties dominate. Our results with different ap

Negative predictive value and potential cost savings of acute nuclear myocardial perfusion imaging in low risk patients with suspected acute coronary syndrome : A prospective single blinded study

Background: Previous studies from the USA have shown that acute nuclear myocardial perfusion imaging (MPI) in low risk emergency department (ED) patients with suspected acute coronary syndrome (ACS) can be of clinical value. The aim of this study was to evaluate the utility and hospital economics of acute MPI in Swedish ED patients with suspected ACS. Methods: We included 40 patients (mean age 55

Spiral wound modules for high viscosity solutions at high temperature: Carrageenan concentration with ultrafiltration

Spiral wound modules are the most common modules in the industry due to their low investment and replacement costs plus high packing density. The use of spiral wound modules is often restricted to feed streams with a low temperature (< 75°C) and a low viscosity. The focus of this paper is on a new generation of spiral wound modules, which has been introduced by Alfa Laval Membrane Technology for t

Disappearance of myocardial perfusion defects on prone SPECT imaging : Comparison with cardiac magnetic resonance imaging in patients without established coronary artery disease

Background: It is of great clinical importance to exclude myocardial infarction in patients with suspected coronary artery disease who do not have stress-induced ischemia. The diagnostic use of myocardial perfusion single-photon emission computed tomography (SPECT) in this situation is sometimes complicated by attenuation artifacts that mimic myocardial infarction. Imaging in the prone position ha

Assessing QCD in deep-inelastic eγ scattering

We consider hadron production in deep inelastic scattering of electrons on photons. 1. (i)Exploiting the leading order QCD corrections due to gluon bremsstrahlung we find that the photon structure functions rapidly approach their asymptotic form which can be calculated in QCD. 2. (ii)Replacing QCD by a theory with a fixed quark-gluon coupling constant (scalar or abelian gluons) gives dramatic chan

Scaling violations in inclusive e+e- annihilation spectra

The origin of the observed scaling violations in inclusive e+e- annihilation is investigated. Perturbative jet evolution is not necessarily the only reason for scale breaking in the hadron spectra at present energies. Remnants of finite-transverse-momentum and mass effects are still important in nonperturbative, cascade-type, jet formation in the 10 GeV range. Heavy-quark fragmentation has a stron

Track finding with neural networks

A neural network algorithm for finding tracks in high energy physics experiments is presented. The performance of the algorithm is explored on modest size samples with encouraging results. It is inherently parallel and thus suitable for execution on a conventional SIMD architecture. More important, it naturally lends itself to direct implementations in custom made hardware, which would permit real