PubMed Health⌕ Search

Biomedical subjects

B Raue

Publications and source records attributed to B Raue.

11 recordsLinked to original sources
PubMed2005

Thioarsenates in sulfidic waters.

It has long been recognized that the formation of soluble arsenic sulfur complexes plays a key role for the mobility and toxicity of arsenic in sulfate-reducing environments. Knowledge of the exact arsenic species is essential to understand the behavior of arsenic in sulfidic aquifers and to develop remediation strategies. In the past, monomeric and trimeric thioarsenites were assumed to be the existing species in sulfidic systems. In this study, thioarsenates were identified by IC-ICP/MS in arsenite- and sulfide-containing solutions as well as in a reduced groundwater from a contaminated site. The unexpected finding of an oxidation of As(lll) to As(V) in thioarsenates in strongly reducing systems can be explained by the high affinity between As(Ill) and sulfur. In sulfide-containing solutions without oxidant, As(lll) therefore undergoes disproportionation to thioarsenates (As(V)) and elemental arsenic. It has previously been supposed that mobility as well as toxicity of arsenic increases if the redox state decreases. For sulfidic waters, the opposite is probably the case. Thus, the formation of thioarsenates could be used in connection with remediation strategies. Thioarsenates are highly sensitive to oxygen and pH. This is important for analytical procedures. A loss of soluble arsenic as well as a conversion to arsenite and arsenate may occur if water samples containing thioarsenates are analyzed with conventional methods.

Arsenates↗
PubMed2004

Measurement of the electric form factor of the neutron at Q2=0.5 and 1.0 GeV2/c2.

The electric form factor of the neutron was determined from measurements of the d-->(e-->,e'n)p reaction for quasielastic kinematics. Polarized electrons were scattered off a polarized deuterated ammonia (15ND3) target in which the deuteron polarization was perpendicular to the momentum transfer. The scattered electrons were detected in a magnetic spectrometer in coincidence with neutrons in a large solid angle detector. We find G(n)(E)=0.0526+/-0.0033(stat)+/-0.0026(sys) and 0.0454+/-0.0054+/-0.0037 at Q(2)=0.5 and 1.0 (GeV/c)(2), respectively.

Journal Article↗
PubMed2003

Measurements of GnE/GnM from the 2H(e-->,en-->)1H Reaction to Q2=1.45 (GeV/c)2.

We report new measurements of the ratio of the electric form factor to the magnetic form factor of the neutron, G(n)(E)/G(n)(M), obtained via recoil polarimetry from the quasielastic 2H(e-->,e(')n-->)1H reaction at Q2 values of 0.45, 1.13, and 1.45 (GeV/c)(2) with relative statistical uncertainties of 7.6% and 8.4% at the two higher Q2 points, which points have never been achieved in polarization measurements.

Journal Article↗
PubMed1977

[Protein and amino acid metabolism in laying hens receiving N-15 labeled casein. 6. Patterns of N-15 incorporation into the N fraction and amino acids of the follicles and residual ovaries].

4 experimental hens were fed labelled casein as sole protein source for a period of 6 days. The dietary nitrogen contained a 15N excess of 0.69 atom%. Hens 1 and 2 were slaughtered 2 days and hens 3 and 4 four days after receiving the last 15N' dose. 10 follicles with diameters more than 6 mm were investigated for their content of N, for the TCE-soluble portion of N (TCE=trichloracetic acid) and for the content of different amino acids in protein. The corresponding 15N' data were established and the same analyses were carried out with the residual ovaries. The mean proportion of the TCE soluble N fraction in the total amount of N was 90% in the follicles and 88% in the residual ovaries. The content of certain kinds of amino acids in follicular protein depends on the degree of maturity of the follicles. There were differences in the percentage composition of amino acids between the follicles and residual ovaries. The mean percentage of lysine contained in follicular protein was 7,2%, that in the residual ovaries 7,9%. Corresponding data for arginine were 6,9% and 7,9%, those for glutamic acid 11,5% and 13,8%, for glycine 3,1% and 5,7%, for alanine 5,0% and 6,1%, for methionine 2,8% and 1,7% and for cystine 3,7% and 2,4%. Less than half of the 15N' atom % and less than half of the percentage of 15N' in the total amount of N and of the amount of amino acids in both the follicles and the residual ovaries were found in the hens killed 144 hrs after the last 15N dose than in the hens slaughtered 48 hrs after the last 15N intake. The atom % of 15N' in the N contained in the amino acids serine, threonine, glutamic acid, proline and leucine decreased with the process of ageing of the follicles. On an average, 88% of the total quantity of 15N' contained in the follicle samples were found as amino acid N, while in the residual ovaries 90% were found.

Amino Acids↗
PubMed1975

[Studies on the protein and amino acid metabolism of laying hens using 15N labeled casein. 15N concentration in the intestinal content and intestinal tissue in relation to the time of the last 15N administration].

Four laying hens with anus praeternaturalis were fed 15N casein for a period of 6 experimental days. Each experimental bird thus received a 15N excess (15N') of 154.44 mg. 11.54 mg of 15N' were found in lysine 3.99 mg in histidine and 9.58 mg in arginine. 2 hens were slaughtered 48 hours after the last 15N dose; another 2 were sacrificed after 144 hrs. In this investigation the N content of the intestinal contents and in the proteins of the small and large intestine were determined. The average N content of the small intestine per hen 2.65% that of the large intestine, 2.60% and, correspondingly, the TCE soluble proportion of N was 21.8% and 20.4%. The percentage of amino acids in the contents of the small intestine was found to change relative to that of the dietary proteins, approximating the protein composition of the intestine. In the first two hens the atom % 15N' was found in the different sections of the intestine and in the intestinal contents varied between 0.14 and 0.28. The data obtained from the two hens slaughtered 144 hours after the last 15N' dose were nearly the same ranging from 0.08 to 0.10 atom % 15n'.

Amino Acids↗