Electrostatic potential in a superconductor

The electrostatic potential in a superconductor is studied. To this end Bardeen's extension of the Ginzburg-Landau theory to low temperatures is used to derive three Ginzburg-Landau equations - the Maxwell equation for the vector potential, the Schroedinger equation for the wave function and the Poisson equation for the electrostatic potential. The electrostatic and the thermodynamic potential compensate each other to a great extent resulting into an effective potential acting on the superconducting condensate. For the Abrikosov vortex lattice in Niobium, numerical solutions are presented and the different contributions to the electrostatic potential and the related charge distribution are discussed.Comment: 19 pages, 11 figure

Automated plasmapheresis compared with other plasma collection methods in the horse

The purpose of this study was to evaluate plasmapheresis as a method for plasma extraction in comparison with centrifugation or gravity sedimentation. The study was designed as a cross over trial with six Freiberger horses undergoing plasma donation by plasmapheresis followed by whole-blood donation and subsequent plasma production 4 weeks later. Automated plasmapheresis and whole-blood donation were well tolerated in all horses. The plasmapheresis method achieved an almost complete removal of erythrocytes and leucocytes from plasma at all flow rates. After blood bag centrifugation, significantly more erythrocytes (P 0.05). However, the activity of factor VIII was significantly lower 24 h after gravity sedimentation of blood than activity prior to blood collection (P < 0.01). In conclusion, automated plasmapheresis is the method of choice for the production of high quality equine plasma

Integrated capillary electrophoresis on flexible silicone microdevices: analysis of DNA restriction fragments and detection of single DNA molecules on microchips.

Microchips for integrated capillary electrophoresis systems were produced by molding a poly(dimethylsiloxane) (PDMS) silicone elastomer against a microfabricated master. The good adhesion of the PDMS devices on clean planar surfaces allows for a simple and inexpensive generation of networks of sealed microchannels, thus removing the constraints of elaborate bonding procedures. The performance of the devices is demonstrated with both fast separations of φX-174/HaeIII DNA restriction fragments labeled with the intercalating dye YOYO-1 and fluorescently labeled peptides. Detection limits in the order of a few zeptomoles (10(-)(21) mol) have been achieved for each injected DNA fragment, corresponding to a mass detection limit of ∼2 fg for the 603 base pair fragment. Single λ-DNA molecules intercalated with YOYO-1 at a base pair-to-dye ratio of 10:1 could be detected with an uncomplicated laser-induced fluorescence detection setup. High single-molecule detection efficiency (>50%) was achieved under electrophoretically controlled mass transport conditions in PDMS microchannels

Sinusitis beim Pferd: Eine retrospektive Untersuchung anhand von 55 Fällen

The records of 55 horses with paranasal sinus disease that were admitted to the Equine clinic, University of Zurich in the years from 1996 to 1999 were reviewed. The horses were 26 mares, 28 geldings and 1 stallion of different breeds aged between 4 and 30 years (10.9±5.3). Physical examination, rhinoscopy, diagnostic imaging, treatment and prognosis were evaluated. Dental disease (n=34) was the most common cause of chronic sinusitis. The typical clinical sign of sinusitis was nasal discharge in 52 cases that was unilateral in 49 cases. In 29 horses the nasal discharge was purulent and had a fetid odor resulting from dental disease in 28 cases. With radiography in 47 cases a fluid line could be visualized in 1 or more sinuses. Signs of dental involvement in 1 or more tooth roots were suspected in 39 cases. However, only in 20 cases it could be diagnosed with certainty based on the radiographs. 25 horses were treated conservatively. Of these horses 5 had to undergo surgery after conservative treatment had failed. Altogether 21 horses underwent surgery. One tooth had to be removed in 13 cases and 2 teeth in one case. They were M1 (n=8), PM4 (n=5), M2 (n=1) or PM3 (n=1). Postoperative complications were common and consisted of chronic sinusitis (n=5), draining tracts (n=4), oral fistula (n=4) or facial wound dehiscence (n=2). Because of complications 6 horses required on additional surgical procedure. 26 horses that were treated for either primary sinusitis or sinusitis caused by dental disease were available for follow-up after 2 months. At this time 18 horses revealed no clinical signs of sinusitis

Reverse protein arrays as novel approach for protein quantification in muscular dystrophies

The definite molecular diagnosis in patients with muscular dystrophies often requires the assessment of muscular expression of multiple proteins in small amounts of muscle tissue. The sample material obtained in muscle biopsies is limited and the measurement of multiple proteins is often restricted to conventional, non-quantitative assays, i.e. immunohistochemistry and immunoblotting. Here, we demonstrate that reverse protein arrays are a novel and excellent material-saving method for the measurement and quantification of changes in protein expression between healthy and diseased muscle tissue as well as cultured primary myotubes. We evaluated a set of antibodies and found reproducible differences between Duchenne muscular dystrophy/limb-girdle muscular dystrophy patients and control samples for dystrophin, the sarcoglycans and the dystroglycans. As little as 10 mg of tissue is sufficient for the analysis of all diagnostically relevant proteins. The average coefficient of variation calculated for the sample signals confirmed that the method is highly reproducible. Thus, our experiments provide strong evidence that quantitative protein detection from very small amounts of muscle tissue is possible using reverse protein arrays. This technology may not only be of interest for diagnostic purposes, but also for protein quantification of multiple, follow-up biopsies during clinical trials when protein expression in muscle is considered an important outcome measure or biomarker

Influence of solvents and detergents on matrix-assisted laser desorption/ionization mass spectrometry measurements of proteins and oligonucleotides.

The effect of solvents was found to be critical for sample preparation in matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). For proteins and oligonucleotides the use of 2-propanol/water as a solvent for different matrices can significantly improve the quality of spectra. This effect is demonstrated with proteins ranging in molecular weight from 12 to 150 kDa and with a special 19-mer oligonucleotide. A comparison of MALDI-MS using of 2-propanol as matrix solvent and high-performance capillary electrophoresis resulted in identical relative peak intensities for a p(dT)12-18 oligonucleotide mixture. Additionally, the effect of detergents for characterization of high molecular weight proteins in very dilute solutions was studied with this solvent. It was found that Triton X-100, up to a concentration of 1%, was highly compatible with MALDI measurements and even could improve the quality of spectra. Use of detergents for cell profiling has extended the detectable mass range to about m/z 75,000