Disposable roll-to-roll hot embossed electrophoresis chip for detection of antibiotic resistance gene mecA in bacteria

We present a high-throughput roll-to-roll (R2R) manufacturing process for foil-based polymethyl methacrylate (PMMA) chips of excellent optical quality. These disposable, R2R hot embossed microfluidic chips are used for the identification of the antibiotic resistance gene mecA in Staphylococcus epidermidis. R2R hot embossing is an emerging manufacturing technology for polymer microfluidic devices. It is based on continuous feeding of a thermoplastic foil through a pressurized area between a heated embossing cylinder and a blank counter cylinder. Although mass fabrication of foil-based microfluidic chips and their use for biological applications were foreseen already some years ago, no such studies have been published previously.     

Collectivity and configuration mixing in 186,188Pb and 194Po

Lifetimes of prolate intruder states in 186Pb and oblate intruder states in 194Po have been determined by employing, for the first time, the recoil-decay tagging technique in recoil distance Doppler-shift lifetime measurements. In addition, lifetime measurements of prolate states in 188Pb up to the 8+ state were carried out using the recoil-gating method. The B(E2) values have been deduced from which deformation parameters |beta2|=0.29(5) and |beta2|=0.17(3) for the prolate and the oblate bands, respectively, have been extracted. The results also shed new light on the mixing between different shapes.     

Spectroscopy of Low-lying States in Odd-Z Odd-A Nuclei Beyond Lead

Low-lying states in odd-Z odd-mass nuclei at the proton drip-line beyond lead have recently been studied through fusion-evaporation reactions using a gas-filled recoil separator. Isomeric 1/2+ and 13/2+ states have been observed in odd-mass astatine and francium nuclei. The systematic behaviour of the level energies of these states have been studied and a similarity between the 1/2+ state in astatine and francium has been found. Furthermore, the 13/2+ state has been observed in the francium nuclei with an oblate behaviour suggesting a coupling of the i_13/2 proton to the 2p-2h intruder excitation.     

Spectrally optimal illuminations for diabetic retinopathy detection in retinal imaging

Optical Review - Retinal photography is a standard method for recording retinal diseases for subsequent analysis and diagnosis. However, the currently used white light or red-free retinal imaging...     

The role of hornification in the disintegration behaviour of TEMPO-oxidized bleached hardwood fibres in a high-shear homogenizer

The effect of 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO)-mediated oxidation on the structure of hornified fibres and their disintegration behaviour was studied by a method combining gradual disintegration of the fibre structure in an in-line homogenizer with a chromatographic separation technique. It was seen that hornification prior to TEMPO-mediated oxidation had a notable effect on the disintegration behaviour of bleached cellulose fibres in a high-shear homogenizer and on the properties of the resulting particles. Field-emission scanning electron microscopy imaging of the suspensions and viscosity and transmittance measurements revealed that never-dried oxidized fibres disintegrated into bunches of microfibrils and at higher charge densities into thinner and more individual microfibrils. These microfibrils were obtained from fibres through swelling and ballooning. The hornified fibres were mainly cut into shorter ones as the charge density increased. After reversing the hornification and allowing the fibres to swell further, however, microfibrils were also obtained from this source. The charge threshold for efficient microfibril production from never-dried fibres in the high-shear homogenizer used here was 0.7 mmol/g.     

Commutator anomalies and the Fock bundle

We show that the anomalous finite gauge transformations can be realized as linear operators acting on sections of the bundle of fermionic Fock spaces parametrized by vector potentials, and more generally, by splittings of the fermionic one-particle space into a pair of complementary subspaces. On the Lie algebra level we show that the construction leads to the standard formula for the relevant commutator anomalies.     

Anodic stripping voltammetry with a symmetric double-step waveform

The high sensitivity of differential pulse anodic stripping voltammetry (d.p.a.s.v.) is based on discrimination against the charging current by using short current-sampling periods near the end of the applied pulses. In this paper, the capacitive current is eliminated by using a symmetric double-step waveform superimposed on the voltage ramp. The areas under the adjacent current peaks are subtracted from each other which effectively cancels the contribution of the double-layer charging current but preserves the changes in the faradaic current. By using a mercury thin-film electrode the base line is reasonably flat down to nanomolar levels of Cd, Cu and Pb with a deposition time of 3–5 min. Compared with d.p.a.s.v., the proposed method has the advantages of a higher scan rate and simple electronic circuitry.     

New 2,2′-Bipyridine Derivatives and Their Luminescence Properties with Europium(III) and Terbium(III) Ions

Twenty differently substituted 2,2′,2″,2? -[(2,2′-bipyridine-6,6′-diyl)bis(methylenenitrilo)]tetrakis(acetc acids) 75–94 were synthesized with the purpose of developing new markers to be used in bioaffinity assays based on the unique luminescence properties of Eu^III and Tb^III ions. The relative luminescence yields, excitation maxima, and emission decay constants were determined for the corresponding Eu^III and Tb^III chelates. The substituents at the bipyridine moiety had a significant effect on the luminescence properties: the best relative luminescence yields R were obtained for ligands with electron-donating substituents (e.g. Me, Ph), electron-withdrawing substituents (e.g. NO₂, COOH) had a reverse effect. However, no clear correlation between the relative luminescence yields and the substituent parameters was found.     

Influence of Chelating Groups on the Luminescence Properties of Europium(III) and Terbium(III) chelates in the 2,2′-bipyridine series

Eight different 2,2′-bipyridine derivatives, i.e. 2, 5, 8, 10, 12, 13, 15 , and 19 (Schemes 1 and 2), were prepared to study the influence of the chelating groups on the luminescence properties of their Eu^III and Tb^III chelates. According to our luminescence results, 2,2′-(methylenenitrilo)bis(acetic acid) as well as (methylenenitrilo)bis-(methylphosphonic acid) in 6- and 6′-position of 2,2′-bipyridine is a suitable group when developing luminescent markers for bioaffinity assays based on time-resolved luminescence measurement.