Filtyp
The influence of poisoning of ruthenium catalysing the selective hydrogenation of benzene to cyclohexene has been studied. Both the yield of cyclohexene and the rate of hydrogenation are greatly affected by the degree of poisoning (e.g. FeSO4, FeCl3, TiCl3 and oxygen), and may also be optimised. A reproducible catalyst has been prepared by precipitating the catalyst precursor, as the hydroxide, in
The equivalence of existence of a Borel section to nonexistence of recurrent aperiodic points for homeomorphisms of locally compact topological spaces is proved using the theory of C*-algebras.
Most applications of positron beams require knowledge of the implantation characteristics for an appropriate interpretation of the experimental data. In this work, the median implantation depth as a function of implantation energy, z1/2(E), of 3–18 keV positrons and their implantation profile P(z,E) in a total of 13 thin films of atactic polystyrene, poly(styrene-co-acrylonitrile), and polymethylm
The reversibly photochromic pigment, phycochrome c, was extracted from the blue-green alga Nostoc muscorum strain A. Action spectra were determined for in vitro conversions of the pigment from the short wavelength to the long wavelength form and vice versa. The action peak for the absorbance decrease at 650 nm is at 630 nm. During this decrease there is only a slight increase of the absorbance in
Popular Abstract in Swedish Det huvudsakliga bidraget i denna avhandling är approximationsalgoritmer för flera problem inom beräkningsgeometri. Den underliggande strukturen för de flesta problemen är ett geometriskt nätverk. Ett geometriskt nätverk är, i sin mest abstrakta form, en mängd noder parvis kopplade med en kant, sådan att vikten på denna kant är lika med det Euklidiska (geometriska) avstThe main contribution of this thesis is approximation algorithms for several computational geometry problems. The underlying structure for most of the problems studied is a geometric network. A geometric network is, in its abstract form, a set of vertices, pairwise connected with an edge, such that the weight of this connecting edge is the Euclidean distance between the pair of points connected. S
Many studies have supported a genetic etiology for autism. Here we report mutations in two X-linked genes encoding neuroligins NLGN3 and NLGN4 in siblings with autism-spectrum disorders. These mutations affect cell-adhesion molecules localized at the synapse and suggest that a defect of synaptogenesis may predispose to autism.
The solubility of tri-n-octylamine (TOA) in water and phosphoric acid is reported. Equilibration is achieved by circulating the solutioin through PVC pieces saturated with the absorbed amine in a glass tube. The dissolved TOA is determined by capillary gas chromatography which can detect amine concentrations down to 10 μg l−1. The solubility of TOA in water is 0.039 mg l−1 and in 5.5 M phosphoric
Whole-lake additions of dissolved inorganic C-13 were used to measure allochthony (the terrestrial contribution of organic carbon to aquatic consumers) in two unproductive lakes (Paul and Peter Lakes in 2001), a nutrient-enriched lake (Peter Lake in 2002), and a dystrophic lake (Tuesday Lake in 2002). Three kinds of dynamic models were used to estimate allochthony: a process-rich, dual-isotope flo
A method for the simultaneous determination of N-methyl-2-pyrrolidone (NMP) and its metabolites 5-hydroxyl-N-pyrrolidone (5HNMP), N-methylsuccinimide (MSI) and 2-hydroxy-N-methylsuccinimide (2HMSI) in plasma and urine has been developed. Samples were purified by SPE using an ASPEC XL4. Analysis was performed using LC-MS equipped with an APCI interface. The analysis provided linear responses in the
About authorial intention and fictional truth in film studies.
The homolytic cleavage of the organometallic Co-C bond in vitamin B-12-dependent enzymes is accelerated by a factor of similar to 10(12) in the protein compared to that of the isolated cofactor in aqueous solution. To understand this much debated effect, we have studied the Co-C bond cleavage in the enzyme glutamate mutase with combined quantum and molecular mechanics methods. We show that the cal
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Backgrounds and aims: To investigate mortality, determinants of mortality, and time until death among elderly subjects receiving public long-term care. Methods: This study comprises 626 respondents (age: 65-98 years). Data were collected for two cohorts (2001 and 2002). Cox regression analysis was used to identify determinants of mortality. Those who died and those who did not die were compared by
Human height is a classic, highly heritable quantitative trait. To begin to identify genetic variants influencing height, we examined genome-wide association data from 4,921 individuals. Common variants in the HMGA2 oncogene, exemplified by rs1042725, were associated with height (P= 4x10(-8)). HMGA2 is also a strong biological candidate for height, as rare, severe mutations in this gene alter body
High-spin states of the neutron deficient nucleus Nb-88 have been studied following the reaction Fe-56 (Cl-35, 2pn) Nb-88 at 120 and 123 MeV bombarding energy. Neutron gated and pure gamma gamma-coincidences were measured with a neutron-gamma gamma-coincidence setup; in addition gamma gamma-coincidences were detected with the OSIRIS-cube at the Cologne tandem accelerator. Via the analysis of gamma
A total of 12 patients previously treated for acute hepatitis of unknown aetiology were retrospectively found to be anti-hepatitis E virus (HEV) IgG-positive. Four patients were anti-HEV IgM- and IgG-positive consistent with an acute HEV infection. All 4 had travelled to or were immigrants from HEV-endemic countries. One anti-HEV IgM-negative patient seroconverted from anti-HEV IgG-negative to pos
