Poison resistant catalysis with microporous catalyst membranes

Amorphous microporous metal oxide membranes containing 1% Pt have been prepared by a modified sol-gel process. The pore diameters of these membranes range from 6 to 9 A and the membranes show a cutoff at MW 180 in liquid phase separation. The membranes are active hydrogenation catalysts and by separating the liquid phase from the hydrogen by the membrane, poison resistant hydrogenation has been achieved. This novel approach to the processing of three phase reactions combines the unique properties of nanofiltration membranes and platinum to obtain a better control over heterogeneous catalysis.     

Anticipatory immune suppression and nausea in women receiving cyclic chemotherapy for ovarian cancer.

Nausea and immune function were assessed in 20 cancer patients in the hospital prior to chemotherapy and compared with assessments conducted at home. Proliferative responses to T-cell mitogens were lower for cells isolated from hospital blood samples than for home samples obtained several days earlier. Patients also experienced increased nausea in the hospital. Hierarchical multiple regression analyses indicated that decreased immune function in the hospital was not related to increased anxiety. The observed anticipatory immune suppression is consistent with the hypothesis that chemotherapy patients may develop conditioned immune suppression as well as conditioned nausea after repeated pairings of hospital stimuli with the emetic and immunosuppressive effects of chemotherapy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Application of robotic technology to automated sequence fingerprint analysis by oligonucleotide hybridisation

We describe our production line for the rapid analysis of large cDNA libraries applying robotic techniques to automatically pick, amplify, array, hybridise and analyse the clones. We also outline the current state of the hybridisation techniques and describe anticipated future developments of the system. Our approach faces the large-scale analysis of cDNA clones with partial sequence analysis by oligonucleotide fingerprinting in the following way: after picking of individual colonies and arraying them automatically in quadruple density (384-well) microtitre plates, the cDNA clones are amplified by an automated waterbath polymerase chain reaction (PCR), which allows us to run about 46,000 reactions in parallel. The PCR products are automatically transferred to nylon membranes in a high density pattern using a robotic device. We routinely produce twelve 22 cm x 22 cm membranes in 90 min. Each membrane contains 20,736 clones, although much higher densities might be feasible using both miniaturized glass matrices and fluorescence based hybridisation techniques. Theoretical analysis and preliminary computer simulations indicate that about 100-200 sequence specific hybridisations of octanucleotides to about 100,000 PCR products of 1000-1500 base-pairs length will generate sufficient information for classifying the clones into groups of identical or related genes and to identify a large number of previously uncharacterized cDNA clones.     

The smallest known eukaryotic genomes encode a protein gene: towards an understanding of nucleomorph functions

Cryptomonads are unicellular algae with plastids surrounded by four membranes. Between the two pairs of membranes lies a periplastidal compartment that harbours a DNA-containing organelle, termed the nucleomorph. The nucleomorph is the vestigial nucleus of a phototrophic, eukaryotic endosymbiont. Subcloning of parts of one nucleomorph chromosome revealed a gene coding for an Hsp70 protein. We demonstrate the expression of this nucleomorph protein-coding gene and present a model for protein transport from the host to the endosymbiont compartment.     

Stressor controllability and the pituitary-adrenal system.

Stressor controllability can alter both behavior and pituitary-adrenal (PAD) activity. Potential mediation of these behavioral effects by differential PAD output requires that the precise conditions that lead to differential behavioral consequences also produce differential PAD activity. In 2 experiments, plasma adrenocorticotropic hormone (ACTH) and corticosterone levels were measured in 152 male Holtzman rats at various times following escapable and yoked inescapable electric shock conditions known to produce differential behavioral outcomes. The escapable and inescapable shock procedures did not produce a detectable differential effect. Both shock conditions produced equivalent elevation of ACTH and corticosterone. Neither decay rates nor the ACTH and corticosterone response to shock reexposure differed among shocked groups. Implications for alterations in immune function and for conceptions of the relation between stress and PAD activity are discussed. (32 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Enhancement of the quality of the reactor pressure vessel used in light water power plants by advanced material,fabrication and testing technologies

Fracture safe assessment of nuclear reactor pressure vessels (RPV) is based upon an adequate stress analysis, reliable material characteristics and acceptable defect sizes.Problems may arise concerning inhomogeneities, low toughness and crack phenomena as observed in the base material and heat affected zone (HAZ). Therefore, efforts have been made to develop a steel which would be both non-susceptible to embrittlement and/or cracking in the HAZ, and have a higher upper-shelf toughness of base and HAZ material. Tests have been made on inhomogeneities and defects and also on improvement of chemical composition, the steel-making process, welding procedures and the optimum temperature cycle and level for stress-relief heat treatment.To solve these problems, common testing methods were supplemented by tangential-cut techniques, small HAZ-tensile test procedures and HAZ-simulation techniques.Results indicate that 50 per cent of 100 investigated component-strength welds are affected by micro stress-relief cracking (SRC) on a micro- and millimetre scale. The 22 NiMoCr 37 steel with optimised chemical composition, and the 20 MnMoNi 55 steel are both resistant to stress-relief embrittlement and SRC. Specific welding techniques are found to limit SRC and proposals for optimum stress-relief temperatures are given.For the generation of new components, the fracture-safe analysis can now be based completely upon homogeneous and high upper-shelf base materials including the HAZ.     

Späneabsaugung an Maschinen

For the exhaustion of wood particles from chipping woodworking machines, a minimum amount of transport air is neede. This amount results from the requirements of the machine concerned and must be specified by the machine manufacturer. Useless great air volumes are of manifold disadvantage: they require expensive exhausters with great capacity, they further cause higher energy cost, increase noise development as well as the tendency to blow out chips. A streamline design of chip conducting machine parts generates advantageous condition and diminishes the required air volume. The constructive principles to be considered are summarized, discussed and are demonstrated by a practical example.