ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • gastrointestinal transit  (4)
  • geostatistics
  • Springer  (7)
  • 1990-1994  (3)
  • 1985-1989  (4)
  • 1955-1959
Collection
Keywords
Publisher
  • Springer  (7)
Years
Year
  • 1
    Electronic Resource
    Electronic Resource
    Regionalization in geology by multivariate classification (1990)
    Springer
    Mathematical geology 22 (1990), S. 573-588 
    Details
    ISSN: 1573-8868
    Keywords: classification ; regionalization ; Bayes' theorem ; geostatistics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Mathematics
    Notes: Abstract The concept of multivariate classification of “geological objects” can be combined with the concept of regionalized variables to yield a procedure for typification of geological objects, such as rock units, well records, or samples. Numerical classification is followed by subdivision of the area of investigation, and culminates in a regionalization or mapping of the classification onto the plane. Regions are subdivisions of the map area which are spatially contiguous and relatively homogeneous in their geological properties. The probability of correct classification of each point within a region as being part of that region can be assessed in terms of Bayesian probability as a space-dependent function. The procedure is applied to subsurface data from western Kansas. The geologic properties used are quantitative variables, and relationships are expressed by Mahalanobis' distances. These functions could be replaced by other metrics if qualitative or binary data derived from geological descriptions or appraisals were included in the analysis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00890505
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Production of conditional simulations via the LU triangular decomposition of the covariance matrix (1987)
    Springer
    Mathematical geology 19 (1987), S. 91-98 
    Details
    ISSN: 1573-8868
    Keywords: geostatistics ; kriging ; conditional simulation ; fast Fourier transform
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Mathematics
    Notes: Abstract This paper reviews the turning band method and fast Fourier transform method of producing a nonconditional simulation of a multinormal random function with a given covariance structure. A review of the two common methods of conditioning the simulation to honor the data shows that they are formally equivalent. Another method for directly pondering a conditional simulation based on the LU triangular decomposition of the covariance matrix is presented. Computational and implementation difficulties are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00898189
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Generating large stochastic simulations—The matrix polynomial approximation method (1987)
    Springer
    Mathematical geology 19 (1987), S. 99-107 
    Details
    ISSN: 1573-8868
    Keywords: geostatistics ; simulation ; Toeplitz matrices ; block Toeplitz matrices ; matrix polynomial approximation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Mathematics
    Notes: Abstract An algorithm for producing a nonconditional simulation by multiplying the square root of the covariance matrix by a random vector is described. First, the square root of a matrix (or a function of a matrix in general) is defined. The square root of the matrix can be approximated by a minimax matrix polynomial. The block Toeplitz structure of the covariance matrix is used to minimize storage. Finally, multiplication of the block Toeplitz matrix by the random vector can be evaluated as a convolution using the fast Fourier transform. This results in an algorithm which is not only efficient in terms of storage and computation but also easy to implement.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00898190
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    The effect of density on the gastric emptying of single- and multiple-unit dosage forms (1986)
    Springer
    Pharmaceutical research 3 (1986), S. 208-213 
    Details
    ISSN: 1573-904X
    Keywords: gastrointestinal transit ; pellet density ; floating formulations, gastric emptying
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The gastric emptying of pellets and single units of different densities has been followed in healthy subjects using the technique of gamma scintigraphy. The gastric emptying of the light pellets was affected by their buoyancy in the upper part of the stomach. However, the mean gastric emptying rates of pellets and single units were not significantly affected by density. Floating or buoyant delivery systems may have little advantage over conventional systems. The presence of food in the stomach was found to be the major factor in determining the gastric emptying of single units.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1016334629169
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Correlation of Phenylpropanolamine Bioavailability with Gastrointestinal Transit by Scintigraphic Monitoring of 111In-Labeled Hydroxypropylmethylcellulose Matrices (1989)
    Springer
    Pharmaceutical research 6 (1989), S. 274-278 
    Details
    ISSN: 1573-904X
    Keywords: bioavailability ; scintigraphy ; gastrointestinal transit ; controlled release ; phenylpropanolamine ; hydroxypropylmethylcellulose
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Two controlled-release hydroxypropylmethylcellulose (HPMC) matrix formulations, a single-unit and a multiple-unit system, have been evaluated in human volunteers. Both formulations contained the sympathomimetic drug phenylpropanolamine hydrochloride and each was radiolabeled with 111Inbound Amberlite IR 120 ion-exchange resin. The formulations were administered to each of six healthy male volunteers and gastrointestinal (GI) transit was monitored using a gamma camera. Serum samples were taken at set time intervals and assayed for phenylpropanolamine content, thus allowing blood drug levels to be correlated with the position of the dosage form in the GI tract. The multiple-unit system emptied from the stomach gradually over a period of about 180 min, when administered after a light breakfast, whereas the single-unit dosage forms had extremely variable gastric emptying times (range, 60 to 〉570 min). However, both formulations provided prolonged phenylpropanolamine blood levels. The differences in the blood profiles obtained with the two formulations were attributed to variations in their in vitro release rates and not to any differences in their GI transit times.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1015986121822
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Variation in Gastrointestinal Transit of Pharmaceutical Dosage Forms in Healthy Subjects (1991)
    Springer
    Pharmaceutical research 8 (1991), S. 360-364 
    Details
    ISSN: 1573-904X
    Keywords: gamma scintigraphy ; variability ; gastrointestinal transit ; pharmaceutical dosage forms
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The variability in the gastrointestinal transit of a multiple-unit and single-unit dosage form was investigated following a light breakfast in six, healthy, male volunteers after repeated weekly administration. The dosage forms were labeled with gamma-emitting radionuclides and the transit of the formulations was monitored on 4 separate study days using the technique of dual-isotope gamma scintigraphy. Gastric emptying times and small intestinal transit times were calculated and compared statistically within and between subjects using the standard deviation and coefficient of variance. The variability in gastric emptying of single- and multiple-unit systems was large; the intrasubject variation being less than the intersubject. There was less variation in small intestinal transit times for the single- and multiple-unit formulations than in gastric emptying, intrasubject variation again being less than intersubject variation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1015849700421
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    In Vivo Evaluation of Enteric-Coated Naproxen Tablets Using Gamma Scintigraphy (1992)
    Springer
    Pharmaceutical research 9 (1992), S. 1436-1441 
    Details
    ISSN: 1573-904X
    Keywords: naproxen ; enteric-coated tablets ; samarium-153 ; neutron activation ; gastrointestinal transit
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Seven healthy, male volunteers were entered into a randomized, open crossover study of the gastrointestinal transit of two enteric-coated 500-mg naproxen tablets. Two radiolabeled tablets were given to each volunteer on two occasions separated by 7 days, once in the fasted state and once after breakfast. Radiolabeling of tablets was achieved by the incorporation of samarium-152 oxide during manufacture, followed by neutron activation of the tablet to produce the gamma-emitting isotope samarium-153. No loss of tablet integrity was seen in the stomach and all tablets disintegrated in the small intestine. Onset of tablet disintegration was controlled predominantly by gastric emptying. Time in the small intestine prior to tablet disintegration was independent of food intake. Naproxen blood levels with time were consistent with the delayed release of naproxen from the tablets. Overall, transit, disintegration, and absorption were as expected from an enteric-coated tablet.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1015858829187
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...