The homolytic Co-C bond dissociation energy (BDE) is central to the understanding of the function of vitamin B12, an important coenzyme of many proteins. We investigate why earlier density functional (B3LYP) estimations of the BDE in methylcobalamin have given so poor results (91-117 kJ/mol) compared to the experimental estimate (155 ± 13 kJ/mol). Improving the basis set increases the discrepancy,

Intracellular lipolysis is a major pathway of lipid metabolism that has roles, not only in the provision of free fatty acids as energy substrate, but also in intracellular signal transduction. The latter is likely to be particularly important in the regulation of insulin secretion from islet beta-cells. The mechanisms by which lipolysis is regulated in different tissues is, therefore, of considera

Exit of recycling cholesterol from late endosomes is defective in Niemann-Pick C1 (NPC1) and Niemann-Pick C2 (NPC2) diseases. The traffic route of the recycling proteoglycan glypican-1 (Gpc-1) may also involve late endosomes and could thus be affected in these diseases. During recycling through intracellular compartments, the heparan sulfate (HS) side chains of Gpc-1 are deaminatively degraded by

Popular Abstract in Swedish "Varje text hur utan värde än / blir lysande som död och sol och stränder, / när jag spelar er förväntan, / detta ojämförligt rika instrument" Så säger Harlequin till sin publik i Paul Anderssons Berättarna från 1955. Spelar med publikens förväntan gör också diktverkets upphovsman. I diktens spegel iscensätts den författargestalt som hade blivit ett fenomen i den litteBeing one of the central poets in the Swedish neo-Romantic movement of the early 1950's, Paul Andersson (1930-1976) was surrounded by a bright authorial aura even before he published his first poems at the age of 21. In 1953, Andersson's reputation became nationwide when the influential poet and critic Karl Vennberg declared him to be a genius. Three years later, Andersson had published his last b

A manikin test probe has been developed to simulate the thermal behaviour of human skin when exposed to thermal conditions likely to occur in fires. The threshold for second-degree burn injuries is evaluated from the temperature readings using a damage integral. The probe has been exposed to different radiation fluxes and the calculated damage criterion for second-degree burn injuries is in agreem

We present a complete Monte Carlo simulation of the transport properties of a Si/SiGe quantum well. The scattering mechanisms, viz. intervalley phonons, acoustic phonons, interface roughness and impurity scattering (including resonant scattering), are considered in detail, and we derive analytic expressions for the scattering rates, in each case properly taking the quantized electron wave function

Doppler shift attenuation lifetime measurements have been carried out for the 3qp and isomeric rotational bands in Y-83 using the reaction (Ni(Si,3p))-Ni-58-Si-28. While the transitional quadrupole moments in the 3qp bands are slightly lower than in the 1 qp bands, we found evidence for a strong reduction in \Q(t)\ for the isomeric band.

Artikeln är en populärvetenskapligt orienterad presentation av forskningsprojektet med samma namn.

An experiment utilizing a double fragmentation reaction was performed to study isobaric analogue states in A similar to 50 nuclei approaching the proton drip-line. gamma-ray spectroscopy will be used to identify excited states in the neutron-deficient nuclei produced in the second fragmentation reaction. Excited state level schemes will be obtained, through comparison with states in their well-kno

Abstract is not available

The dynamics of visible-to-ultraviolet upconversion in YAlO3: 1% Er3+ crystal has been investigated using the time-resolved laser spectroscopy when the sample was excited into the S-4(3/2) multiplets. It is found that the upconverted luminescence is produced by energy-transfer upconversion or by excited-state absorption depending on the excitation wavelength. The dependence of upconverted luminesc

For linear time-invariant systems Bode's sensitivity integral is a well-known formula that quantifies some of thelimitations in feedback control. In this paper we show that a very similar formula holds for linear time-periodicsystems. We use the infinite-dimensional frequency-response operator called the harmonic transfer function to prove the result. It is shown that the harmonic transfer functio

In several organisms, expression of a gene encoding dimeric hemoglobin (VHb) from the obligate aerobic bacterium Vatreoscilla stercoraria has been shown to increase microaerobic cell growth and enhance oxygen-dependent cell metabolism. In an attempt to further improve these effects of VHb, a gene encoding two vhb genes connected by a short linker of six base pairs was constructed and expressed in

In this report slow frequency-hopping systems are analyzed with respect to the probability of successful transmission of packets, and with respect to the throughput. It is assumed that collisions result in a loss of all information contained in the colliding packets, irrespective of the distance between the units of the system. Units transmit packets of different types with a certain probability,

BACKGROUND: The Cromer blood group system consists of seven high-incidence and three low-incidence antigens carried on decay-accelerating factor (DAF). This report describes the identification and characterization of a new Cromer high-incidence antigen, named GUTI. STUDY DESIGN AND METHODS: RT-PCR and sequence analysis were performed on cDNA prepared from a Chilean donor whose serum contained the