Purification of serum amyloid A and its isoforms from human plasma by hydrophobic interaction chromatography and preparative isoelectric focusing.

The present work was aimed at isolating human serum amyloid A, (SAA), an acute-phase protein mainly complexed to high density lipoproteins, directly from human plasma without sequential ultracentrifugation of lipoproteins and subsequent delipidation of the apolipoprotein moiety. Hydrophobic-interaction fast-protein liquid chromatography on Octylsepharose, using stepwise gradient elution profiles under dissociating conditions, followed by fast-protein liquid-gel permeation chromatography on a Superdex TM75 column revealed a higher than 95% purity of isolated SAA. Further purification of SAA from coeluting apolipoproteins C and A-II was achieved by preparative isoelectric focusing between pH5-7 using a Rotofor apparatus. Separation of the main SAA isoforms, SAA1 (pI 6.5) and SAA1 des-Arg (pI 6.0, lacking the N-terminal arginine), was achieved by anion-exchange fast-protein liquid chromatography on a Fractogel EMD DEAE 650-S column. The purity of the SAA1 and SAA1 des-Arg isoforms, thus isolated, was checked by immunochemical techniques and amino acid analysis. With the described method various SAA isoforms can be isolated, purified and separated directly from human plasma/serum without prior ultracentrifugation.     

Recherche de matériauxa`conductivitéionique ame´liore´e de´rivant des hydrurofluorures de calcium CaF2−xHx: conductivite´ ionique des phases Ca1−yNay(F2−xHx)1−y/2

The doping of CaF_2?xH_x hydridefluorides by aliovalent ions is studied, the aim being the preparation of materials of improved ionic conductivity. It is shown that doping by monovalent Na⁺ ions is possible. Three hydrogen-rich phases, formulated Na_yCa_1?y(F_2?xH_x)_1?y/2 have been studied. Their conductivity is mainly ionic, but, compared with the same doping in CaF₂, the conductivity enhancement is low. This result is interpreted from energetic and structural considerations.     

Fabry–Pérot filter cavities for wide-spaced frequency combs with large spectral bandwidth

We use low-finesse Fabry–Pérot cavities in series to generate frequency combs with a large mode spacing in a way that allows its application to a large optical bandwidth. The attenuation of laser modes closest to the pass bands of the cavity exceeds 70 dB for a filter ratio of m=20 relative to the resonant modes centered within the pass bands. We also identify the best cavity geometry to suppress spurious transmission of higher order transversal modes. Such a thinned out frequency comb can be used to calibrate traditional spectrographs for precision astronomy. In the time domain mode filtering generates a pulse train with a multiplied repetition rate. High-fidelity filtering, as described here, implies small variations of the pulse energies.     

Reuse,Recycle, Reduce (3R) – strategies for the calculation of transient magnetic fields

The discretization of transient magneto-dynamic field problems with geometric discretization schemes such as the Finite Integration Technique or the Finite-Element Method based on Whitney form functions results in nonlinear differential-algebraic systems of equations of index 1. Their time integration with embedded s-stage singly diagonal implicit Runge–Kutta methods requires the solution of s nonlinear systems within one time step. Accelerated solution of these schemes is achieved with techniques following so-called 3R-strategies (“reuse, recycle, reduce”). This involves e.g. the solution of the linear(-ized) equations in each time step where the solution process of the iterative preconditioned conjugate gradient method reuses and recycles spectral information of linear systems from previous stages. Additionally, a combination of an error controlled spatial adaptivity and an error controlled implicit Runge–Kutta scheme is used to reduce the number of unknowns for the algebraic problems effectively and to avoid unnecessary fine grid resolutions both in space and time. First numerical results for 2D nonlinear magneto-dynamic problems validate the presented approach and its implementation. The space discretization in the numerical examples is done by Lagrangian nodal finite elements but the presented algorithms also work in combination with other discretization schemes for the Maxwell equations such as the Whitney vector finite elements.     

A NEW FINITE ELEMENT APPROXIMATION OF A STATE-CONSTRAINED OPTIMAL CONTROL PROBLEM

In this paper, we study numerical methods for an optimal control problem with pointwise state constraints. The traditional approaches often need to deal with the deltasingularity in the dual equation, which causes many difficulties in its theoretical analysis and numerical approximation. In our new approach we reformulate the state-constrained optimal control as a constrained minimization problems only involving the state, whose optimality condition is characterized by a fourth order elliptic variational inequality. Then direct numerical algorithms （nonconforming finite element approximation） are proposed for the inequality, and error estimates of the finite element approximation are derived. Numerical experiments illustrate the effectiveness of the new approach.     

Two-dimensional electrophoresis of plasma proteins and high density lipoproteins during inflammation

Plasma protein and lipoprotein fractions of five patients were analyzed on day 1, 5, and 15 after severe head injury by combining three types of two-dimensional electrophoresis (2-DE) to obtain information on lipoprotein and apolipoprotein composition. On analysis under nondenaturing conditions in both dimensions on day 5, the samples show modifications of isoelectric point (pI) and molecular weight (Mr) properties of the high density lipoprotein (HDL) fraction in addition to an increase in inflammatory proteins and a return to a normal pattern on day 15. In the second type of 2-DE the samples were analyzed employing isoelectric focusing without denaturant in the first dimension, followed by sodium dodecyl sulfate (SDS) in the second dimension in order to study the protein composition of lipoprotein fractions. On day 5, a decrease of the apolipoproteins apo A-I, apo A-II, and apo C were noted, with simultaneous appearance of an unidentified protein with Mr 12,000 and pI 6.0. In the third type of 2-DE, employing urea and Nonidet P-40 in the first and SDS in the second dimension, the plasma polypeptide composition was studied. The presence of an unidentified polypeptide could be confirmed on day 5, tending to disappear thereafter. This Mr 12,000 component consists of two major spots at pI 5.7 and 6.0 and four minor ones between pI 6.0 and 8.0. These properties suggest that this protein corresponds to serum amyloid A apolipoprotein.     

Meromorphe Funktionen,die mit ihrer Ableitung Werte teilen

In this paper it is shown that the functions f(z)=e^z are the only nonconstant entire (meromorphic) functions which share two (three) distinct finite values with their derivative.     

On Painlevé's equations I, II and IV

We give a new proof of the fact that the solutions of Painlevé's differential equations I, II and IV are meromorphic functions in the complex plane. The method of proof is based on differential inequality techniques.