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  • 1995-1999  (2)
  • 1985-1989  (8)
  • 1975-1979  (6)
  • Engineering General  (9)
  • Chemistry  (5)
  • Biochemistry and Biotechnology  (1)
  • Chimpanzee  (1)
  • Key words Nitrification  (1)
  • 57Q45
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  • 1
    ISSN: 1432-0738
    Keywords: Chenodeoxycholic acid ; Chimpanzee ; Conjugation ; Lithocholic acid ; Sulfation ; Toxicity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Um im Schimpansen die hepatische Biotransformation der primären Gallensäure Chenodeoxycholsäure und deren wichtigstem bakteriellen Metaboliten, Lithocholsäure zu charakterisieren, wurde ein Gemisch aus Spurenmengen von14C-Lithocholsäure und3H-Chenodeoxycholsäure intravenös in zwei Tiere mit Gallenfistel injiziert. Die chemische Form der Radioaktivität, die in der Galle erschien, wurde dünnschichtchromatographisch ermittelt. Etwa 80% der Chenodeoxycholsäure und 70% der Lithocholsäure wurden innerhalb von 90 min ausgeschieden. Die Chenodeoxycholsäure war vollständig konjugiert und erschien vorwiegend als Chenyltaurin (52%) und Chenylglycin (37%). 11% erschienen in einer Form, die bisher nicht identifiziert wurde. Lithocholsäure wurde vollständig als Taurin- und Glycinkonjugat in die Galle eliminiert; der größte Teil (63%) war zusätzlich sulfatiert. Die Sulfatierung nahm stetig mit der Zeit zu und Lithocholylglycine wurde stärker sulfatiert als Lithocholyltaurin. Wir schließen aus diesen Befunden, daß der Schimpanse mit dem Menschen vergleichbar ist, indem er Lithocholsäure effektiv sulfatiert. Dadurch unterscheidet sich der Schimpanse vom Rhesusaffe und Baboon, die die Lithocholsäure nur in geringem Maße sulfatieren. Jedoch unterscheidet sich der Schimpanse auch vom Menschen und ähnelt dem Rhesusaffen und dem Baboon, indem er Gallensäure vorwiegend mit Taurin konjugiert. Die Ergebnisse lassen den Schluß zu, daß die Hepatotoxizität, die im Rhesusaffe und Baboon durch Chenodeoxycholat hervorgerufen wird, und auf eine geringe Sulfatierung der Lithocholsäure zurückgeführt wird, beim Schimpansen nicht bestehen sollte.
    Notes: Abstract To characterize the hepatic biotransformation in the chimpanzee of the primary bile acid chenodeoxycholic acid (chenic) and its major bacterial metabolite lithocholic acid (lithocholic) a mixture of tracer amounts of14C-lithocholic and3H-chenic was injected intravenously into two animals with a bile fistula; the chemical form of radioactivity appearing in bile was inferred using thin layer chromatography. About 80% of chenic, and 70% of lithocholic was recovered in 90 min. Chenic was completely conjugated in bile, appearing predominantly as chenyltaurine (52%) and chenylglycine (37%). An unidentified conjugate (about 11%) was also found. Lithocholic was excreted completely as taurine and glycine conjugates, but the majority (63%) of conjugates was sulfated. Sulfation increased progressively with time, and lithocholylglycine was sulfated more than lithocholyltaurine. We conclude that the chimpanzee is similar to man in that the secondary bile acid lithocholic is efficiently sulfated. The chimpanzee thus differs from the baboon and rhesus monkey which sulfate lithocholic poorly. However, the chimpanzee differs from man and is similar to the baboon and rhesus monkey in showing preferential conjugation of bile acids with taurine. The results imply that hepatotoxicity caused by chenic, which is well documented in the rhesus monkey and baboon and has been related to defective lithocholic sulfation, should not occur in the chimpanzee.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1432-072X
    Keywords: Key words Nitrification ; Hydroxylamine-cytochrome c oxidoreductase ; Ammonia monooxygenase ; Denitrification ; Pseudomonas sp.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Hydroxylamine oxidation was measured in four recently isolated heterotrophic nitrate-reducing bacteria belonging to the genera Pseudomonas, Moraxella, Arthrobacter and Aeromonas. A hydroxylamine-cytochrome c oxidoreductase activity was detected in periplasmic fractions of the Pseudomonas and Aeromonas spp. and in total soluble fractions of the Arthrobacter sp. A monomeric 19-kDa non-haem iron hydroxylamine-cytochrome c oxidoreductase was purified from the Pseudomonas species and shown to be similar to hydroxylamine-cytochrome c oxidoreductase of Paracoccus denitrificans.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 0887-3585
    Keywords: bioactivity ; SK-hep-1 hepatoma ; interleukin-1 ; recombinant protein ; crystals ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The gene for human interleukin-1β was cloned from SK-hep-1 hepatoma cellular RNA and expressed at high levels in Escherichia coli both as the naturally processed form (rIL-1β) and as a variant with an additional sequence of three amino acids on the N-terminus (rIL-1β+). Expressed protein was purified to homogeneity by a sequence of steps, which included low pH incubation, adsorption and desorption from Procion Red Sepharose, sizing on a Superose 12 fast-performance liquid chromatography (FPLC) column, and anion exchange chromatography on QAE Sepharose. The final step provided a biologically active protein that migrates on twodimensional (2-D) gels as a single spot with a pI of 6.7 ± 0.2 and a molecular mass of 17,500 daltons. Concentrated solutions of rIL-1β have produced crystals by ammonium sulfate precipitation. The crystals are tetragonal, show the symmetry of space group P41 or its enantiomer, have lattice constants of a = 58.46 (1) and c = 77.02 (3) A, and scatter to at least 2 Å resolution. A structure determination based on these crystals is under way.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 21 (1975), S. 380-382 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    Journal of Biomedical Materials Research 12 (1978), S. 1-12 
    ISSN: 0021-9304
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: The rotating ring-disk electrode technique has been applied to the study of anodic dissolution of dental amalgam in a simulated saline solution.The electroactive domains of the silver, tin, and mercury couples (the main constituents of the amalgam) were determined from current-potential curves obtained at a rotating gold-disk electrode in solutions containing salts of the respective metals. Subsequently, anodic currents were applied to a rotating amalgam-disk electrode and the soluble products produced were identified using a concentric gold ring electrode, i.e., using the rotating gold-ring, amalgam-disk electrode. Species generated at the amalgam disk are transferred to the gold ring by convective diffusion. Tin ions were found to be the only soluble species generated at the amalgam disk. No evidence for dissolution of other components was found. The selective dissolution of tin from the amalgam is also consistant with potential shifts observed in repetitive current-potential curves of an amalgam disk.This study provides a direct proof for the selective dissolution of tin during corrosion of dental amalgam in an in vitro environment.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    Journal of Biomedical Materials Research 22 (1988), S. 137-148 
    ISSN: 0021-9304
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: Studies have shown synthetic calcium phosphates such as hydroxyapatite and beta tricalcium phosphate to be biocompatible in vivo. However, few studies have quantitated histological responses to the implants.The aim of this study was to develop a method for the quantitative assessment of tissue biocompatibility to ceramic materials in vivo and to use this method to compare noncarbonated and carbonated apatite implants. Synthetic sintered apatites of 0, 3, and 6% carbonate by weight were prepared and cut into implants 4 × 4 × 1 mm. These were placed 2 mm into the medial aspect of rat fermurs. Following sacrifice at 4 weeks, the femurs were fixed in formalin, demineralized in formic acid, and embedded in glycol methacrylate. Sections were cut on an ultramicrotome set at 1.5 μm and stained with toluidine blue. A point counting technique using standard stereological grids and a low-power microscope was used to measure areas of new bone formation. The width of the connective tissue zone adjacent to muscle was measured using an image analyzer. All implants were well accepted by the host tissues judging from criteria of minimal inflammation and degree of fixation. Results showed an increase in new bone formed in the marrow cavity with increasing carbonate content. This may improve stability of the implant in the host bone, particularly during the initial healing period. A technique which should enable quantitative histological evaluation of different ceramic materials has been developed. The use of this method indicates that further studies are warranted to investigate carbonated apatite as an implant material.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 0021-9304
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: In order to study the influence of residual stresses on dimensional accuracy and mechanical properties of denture bases, an experimental model was devised for measurement of residual stresses in acrylic denture base polymers. Rectangular bar coupons were cut from resin plates heat processed by conventional dental methods. They included samples which had been slow and fast cooled after polymerization and had been stored in dry and wet environments. Uniaxial residual stress distributions for each coupon were disclosed by removing layers of known thicknesses and measuring the ensuing deflection of the specimens. Coupons of a commercial acrylic resin were annealed and used as controls. ANOVA and Scheffe's test were used to compare experimental conditions at the 95% confidence level. Dry specimens exhibited residual surface compressive stresses from 0.43-0.83 MPa (62-120 psi). Water-stored specimens showed higher stress levels, 2.86-3.24 MPa (414-470 psi). Slow cooled pigmented acrylic coupons which were dry showed higher residual stresses compared with other dry but nonpigmented specimens. No significant differences were found between pigmented or clear coupons which contained moisture.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    International Journal for Numerical and Analytical Methods in Geomechanics 11 (1987), S. 61-77 
    ISSN: 0363-9061
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Architecture, Civil Engineering, Surveying , Geosciences
    Notes: The complete solution is presented for the transient effects of pumping fluid from a point sink embedded in a saturated, porous elastic half-space. It is assumed that the medium is homogeneous and isotropic with respect to its elastic properties and homogeneous but anisotropic with respect to the flow of pore fluid. The soil skeleton is modelled as a linear elastic material obeying Hooke's law, while the pore fluid is assumed to be incompressible with its flow governed by Darcy's law. The solution has been evaluated for a particular value of Poisson's ratio of the solid skeleton, i.e. 0.25, and the results have been presented graphically in the form of isochrones of excess pore pressure and surface profile for the half-space. The solutions presented may have application in practical problems such as dewatering operations in compressible soil and rock masses.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    International Journal for Numerical and Analytical Methods in Geomechanics 10 (1986), S. 137-150 
    ISSN: 0363-9061
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Architecture, Civil Engineering, Surveying , Geosciences
    Notes: Closed-form solutions are presented for the steady-state distributions of displacement, pore pressure and stress around a point sink embedded in a homogeneous, isotropic elastic half space. These solutions have been evaluated for a typical case of a sink (pump) buried in sand and the magnitude of the settlement of the ground surface has been estimated.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    International Journal for Numerical and Analytical Methods in Geomechanics 1 (1977), S. 25-43 
    ISSN: 0363-9061
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Architecture, Civil Engineering, Surveying , Geosciences
    Notes: Presented in this paper is a formulation and a numerical solution method for problems which involve finite deformations of an elasto-plastic material. The governing equations are cast in rate form and the constitutive laws are formulated in a frame indifferent manner. Particular reference is made to the finite deformation of soil. Plastic failure is described by a general yield condition and plastic deformation by an arbitrary flow rule. Several examples are treated numerically.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
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