Mask-based dual-axes tomoholography using soft x-rays

We explore tomographic mask-based Fourier transform x-ray holography with respect to the use of a thin slit as a reference wave source. This imaging technique exclusively uses the interference between the waves scattered by the object and the slit simplifying the experimental realization and ensuring high data quality. Furthermore, we introduce a second reference slit to rotate the sample around a second axis and to record a dual-axes tomogram. Compared to a single-axis tomogram, the reconstruction artifacts are decreased in accordance with the reduced missing data wedge. Two demonstration experiments are performed where test structures are imaged with a lateral resolution below 100 nm

Purification and quantification of recombinant Epstein-Barr viral glycoproteins gp350/220 from Chinese hamster ovary cells

Truncated Epstein-Barr virus (EBV) membrane antigen gp350/220 (EBV-MA) lacking the membrane anchor was expressed and secreted into the medium of recombinant Chinese hamster ovary cells that had been cultured in Plasmapur hollow-fibre modules using defined serum-free medium. The EBV-MA in the medium was concentrated by 70% (w/v) ammonium sulphate precipitation and subsequently purified by immunoaffinity chromatography using an anti-EBV-MA (EBV.0T6) monoclonal antibody (mAb) column. Adsorbed antigen was eluted with 3 M MgCl2 in phosphate-buffered saline, concentrated by Mono Q anion-exchange chromatography and analysed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis, silver staining and Western blotting using EBV-positive serum and anti-EBV-MA specific mAbs. Monospecific polyclonal rabbit antibodies against the purified EBV-MA were raised and purified by protein G affinity chromatography. For the measurement of EBV-MA antigen levels a sandwich enzyme-linked immunosorbent assay using rabbit polyclonal antibodies and a horseradish peroxidase-conjugated anti-MA mAb was developed having a detection level of 10 ng/ml

Protein S binding in relation to the subunit composition of human C4b-binding protein

AbstractThe human regulatory complement component C4b-binding protein (C4BP) circulates in plasma either as a free protein or in a bimolecular complex with the vitamin K-dependent protein S. The major form of C4BP is composed of 7 identical, disulfide-linked 70 kDa subunits (α-chains), the arrangement of which gives the C4BP molecule a spider-like appearance. Recently, we identified a unique 45 kDa subunit (β-chain) in C4BP. We have now isolated a subpopulation of C4BP, which does notbind protein S. This C4BP species, which had a molecular weight slightly lower than that of the predominant form, was found to lack the β-chain. Another lower molecular weight form of C4BP was also purified. It contained the β-chain and was efficient in binding protein S. Its subunit composition was judged to comprise six α-chains and one β-chain. These results indicate C4BP in plasma to be heterogeneous at a molecular level vis-a-vis subunit composition and/or protein S binding ability and provide support for the concept that the β-chain of C4BP contains the single protein S binding site

Systems of donor transfer

The development of medical knowledge has resulted in a demand in society for donor organs, but the recruitment of donor organs for transplantation is difficult. This paper aims to provide some general insights into the complex interaction processes involved. A laissez-faire policy, in which market forces are relied on, is not acceptable from an ethical and legal point of view in most western European countries. Especially at the demand side of the exchange of donor organs, commercialism is to be opposed. We judge the use of commercial incentives at the supply side less unacceptable in theory but not feasible in western European countries. Since market forces are deemed unacceptable as instruments for coordinating demand and supply of donor organs, donor procurement has to be considered as a collective good, and therefore governments are faced with the responsibility of making sure that alternative interaction and distribution mechanisms function. The role of organ procurement agencies (OPAs) in societal interaction concerning postmortem organ donation is described using a two-dimensional conceptualisation scheme. Medical aspects of living organ donation are described. An international comparative description of legal systems to regulate living organ donation in western European countries completes this survey

Needy or Greedy? The Social Psychology of Individuals Who Fraudulently Claim Unemployment Benefits

This study explored the relationships between diverse social psychological and economic variables and self‐reported and officially documented unemployment benefit fraud. Two groups receiving unemployment benefit were studied; a fraudulent group of 45 individuals and an honest group of 51 individuals. Interview measures of financial strain, social norms, opportunity for fraud, social controls, personal strain, personal orientation, perceived risk of punishment, and intolerance of fraud were obtained. The results of univariate and regression analyses revealed that although financial strain and social norms did not differ between the two groups, the fraudulent group had more opportunity, were less well educated, were more alienated and inclined to take risks, and had more positive attitudes toward a variety of kinds of fraud. Copyrigh