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Digitale Medien

Single-dose toxicokinetics of aluminum in the rat (1992)

Wilhelm, M. ; Zhang, X. -J. ; Hafner, D. ; [weitere]

Springer

Archives of toxicology 66 (1992), S. 700-705

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ISSN: 1432-0738

Schlagwort(e): Aluminum ; Toxicokinetics ; Rat ; Parenterals

Quelle: Springer Online Journal Archives 1860-2000

Thema: Medizin

Notizen: Abstract The toxicokinetics of aluminum (Al) in male Wistar rats was studied after single intragastric (IG) doses of 1000 and 12000 μg Al/kg and intravenous (IV) doses of 10, 100, 1000, and 12000 μg Al/kg. Serial blood samples, daily samples of urine and feces as well as brain, liver, kidney, spleen, quadriceps muscle, and femur samples were collected. Al was measured by atomic absorption spectrometry. Al blood profiles after IV doses were adequately described by a two-compartment open model. Al toxicokinetics was dose dependent and appeared to plateau at 12000 μg/kg. At IV doses between 10 and 1000 μg/kg the terminal half-life of elimination from whole blood (t1/2β) increased from 29.9±7.8 to 209.3±32.6 min, and the total body clearance (CL) decreased from 2.45±0.64 to 0.28±0.03 ml min−1 kg−1. Following an IV bolus of 10 and 100 μg/kg the administered Al was recovered completely from urine (94.4%±9.9% and 98.5%±3.2%). Twenty-nine days after the IV dose of 1000 μg/kg daily renal excretion decreased to baseline values while only 55.1%±8.0% of the dose was excreted. Nineteen days after the single IV dose of 1000 μg/kg Al accumulated in liver (28.1±7.7 versus 1.7±0.5 μg/g of control rats) and spleen (72.5±21.1 versus 〈0.4 μg/g). After the single 1000 μg/kg IG dose no absorption of Al was detectable. The IG dose of 12000 μg/kg resulted in a maximum blood Al level of 47.9±12.4 μg/l after 50 min. The blood concentration time curve fitted a one-compartment open model with a half-life of absorption of 28.2±3.6 min and a t1/2β of 81.2±20.2 min. Cumulative renal Al excretion was 0.18%±0.10% of the dose and oral bioavailability was 0.02%. Seventeen days after the 12000 μg/kg IG dose the Al content in femur samples was increased (2.7±1.3 versus 0.6±0.4 μg/g). In no case was fecal elimination of incorporated Al observed.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1007/BF01972620

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Digitale Medien

Application of the finite element method to the simulation of sheet forming processes: Comparison of calculations and experiments (1990)

Keck, P. ; Wilhelm, M. ; Lange, K.

Chichester [u.a.] : Wiley-Blackwell

International Journal for Numerical Methods in Engineering 30 (1990), S. 1415-1430

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Details

ISSN: 0029-5981

Schlagwort(e): Engineering ; Engineering General

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Mathematik , Technik allgemein

Notizen: Elastic-plastic finite element calculations have been carried out to analyse sheet forming processes such as hydrostatic bulging of circular and rectangular blanks and the axisymmetric stretching of sheets (with different punch radii). The results, partly obtained by different finite element models, are compared with experimental data. It could be shown that, regarding the examples considered, experiments and calculations fit well and that a more sophisticated modelling of the contact boundary conditions improves the accuracy of the results. As a first attempt to handle more complex sheet forming operations, the deep drawing of a rectangular cup has been analysed. A summary of the theoretical background as well as some comments on the solution method and the implementation are given.

Zusätzliches Material: 15 Ill.